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Aims: To develop and validate equations predicting heart rate (HR) at the first and second ventilatory thresholds (VTs) and an optimized range-adjusted prescription for patients with cardiometabolic disease (CMD). To compare their performance against guideline-based exercise intensity domains., Methods and Results: Cross-sectional study involving 2868 CMD patients from nine countries. HR predictive equations for first and second VTs (VT1, VT2) were developed using multivariate linear regression with 975 cycle-ergometer cardiopulmonary exercise tests (CPET). 'Adjusted' percentages of peak HR (%HRpeak) and HR reserve (%HRR) were derived from this group. External validation with 1893 CPET (cycle-ergometer or treadmill) assessed accuracy, agreement, and reliability against guideline-based %HRpeak and %HRR prescriptions using mean absolute percentage error (MAPE), Bland-Altman analyses, intraclass correlation coefficients (ICC). HR predictive equations (R²: 0.77 VT1, 0.88 VT2) and adjusted %HRR (VT1: 42%, VT2: 77%) were developed. External validation demonstrated superiority over widely used guideline-directed intensity domains for %HRpeak and %HRR. The new methods showed consistent performance across both VTs with lower MAPE (VT1: 7.1%, VT2: 5.0%), 'good' ICC for VT1 (0.81, 0.82) and 'excellent' for VT2 (0.93). Guideline-based exercise intensity domains had higher MAPE (VT1: 6.8-21.3%, VT2: 5.1-16.7%), 'poor' to 'good' ICC for VT1, and 'poor' to 'excellent' for VT2, indicating inconsistencies related to specific VTs across guidelines., Conclusion: Developed and validated HR predictive equations and the optimized %HRR for CMD patients for determining VT1 and VT2 outperformed the guideline-based exercise intensity domains and showed ergometer interchangeability. They offer a superior alternative for prescribing moderate intensity exercise when CPET is unavailable., Competing Interests: Conflicts of interest: No potential conflict of interest is reported by the authors., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Purpose: Cardiopulmonary exercise test (CPET) is a common method for preliminary evaluating coronary heart disease (CHD), but it may experience false positive. The present study aimed to reveal the potential factors relating to the false positive of CPET, including blood glucose and lipids., Methods: This observational cohort study included 103 subjects with false positive of CPET and 65 subjects with true positive of CPET. The baseline characteristics, blood glucose, and blood lipids between the true and false positive groups were compared. After adjusting for the age and sex, logistic regression analysis was performed to reveal the potential risk factors of false positive. Receiver operating characteristic curve analysis was performed to evaluate the potential of related factors in distinguishing between true and false positive results., Results: Males, smokers, and patients with diabetes were less likely to suffer from false positive of CPET. Compared with the true positive group, the false positive group exhibited significantly higher levels of high-density lipoprotein (HDL) and apolipoprotein A1 (Apo-A1), and lower levels of fasting blood glucose (FBG) and glycosylated hemoglobin (GHb). After adjustment, FBG and GHb were protective factors of the true positive of CPET, and they both had moderate ability to distinguish false positive from true positive in females. However, their combination did not improve the discriminative effect more obviously than FBG alone., Conclusions: Sex, smoking, diabetes, and blood glucose were associated with the false positive of CPET. FBG was valuable in predicting the risk of false positive of CPET in females with suspected CHD., Trial Registration: The present study is registered in Chinese Clinical Trial Register (ChiCTR2400089239)., Competing Interests: Declarations Ethics approval and consent to participate The studies involving humans were approved by The First affiliated Hospital of Ningbo University (2023-185RS-01). Written informed consent was obtained from all participates. The present study is registered in Chinese Clinical Trial Register (ChiCTR2400089239). Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

Background: Endurance training enhances exercise capacity and triggers cardiovascular adaptations in both males and females. We investigated the relationship between the dimensions of great vessels and exercise capacity in amateur cyclists while considering sex differences., Methods: Using resting transthoracic echocardiography, we measured the dimensions of the main pulmonary artery (PA), aorta, and inferior vena cava (IVC) in 190 participants, who subsequently underwent a cardiopulmonary exercise test (CPET) until exhaustion., Results: The mean age of study participants was 30 years. Males (71%) exhibited a larger aortic annulus (approximately 3.5 mm, p<0.0001) and PA diameter (2.4 mm, p<0.0001) than females. No significant sex differences were found in expiratory or inspiratory IVC diameters. Males achieved greater peak exercise capacity, including workload, O2 consumption (VO2), and O2 pulse. Aortic and PA dimensions showed strong correlations with energy expenditure, workload, VO2, and O2 pulse. However, these correlations weakened when analyzed separately by sex. Multivariate linear regression revealed associations between CPET results, vessels size, and sex, with sex differences observed only in the intercepts-not in interactions between sex and vessels size. Despite males having better CPET results and larger vessels, the relationships between peak exercise capacity parameters and vessel dimensions were similar in both sexes., Conclusion: Larger vessel dimensions (of the aorta, PA, and IVC) were associated with greater peak exercise capacity in amateur cyclists, with no significant sex differences in these associations., Competing Interests: I have read the journal’s policy and the authors of this manuscript have the following competing interests: This study and the Open Access article publication charges was partially funded by the budget for the Project "Development of the University Centre for Sports and Medical Studies in Poznan, Poland" (Number: NdS/544750/2021/2022) with Principal Investigator Prof. Przemysław Guzik. The Ministry of Education and Science, Warsaw, Poland, funded the Project within the "Science for Society" Program. The funding for this scientific work was partially provided by the budget for the science of The Polish Ministry of Science and Higher Education as a research project of the program "Diamond Grant" (0184/DIA/2020/49). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the ’Author Contributions’ Section. This does not alter our adherence to PLOS ONE policies on sharing data and materials., (Copyright: © 2024 Pytka et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

We retrospectively investigated the relationship between cardiopulmonary exercise testing (CPET) parameters and coronary microvascular dysfunction (CMD) using a novel angiography-based index of microcirculatory resistance (AccuIMR) in patients with ST-elevation myocardial infarction (STEMI) who underwent primary percutaneous coronary intervention (PCI) with complete revascularization. In 418 patients, the culprit vessel AccuIMR was calculated after successful primary PCI. CPET was conducted 44.04 ± 19.28 days after primary PCI. Overall, 157 patients (37.6%) showed elevated AccuIMR (> 40 U) in the culprit vessels. The LVEF was significantly lower in the CMD group than in the Non-CMD group. The CMD group showed worse results in VO2peak, peak O2-pulse, and VE/VCO2 slope than the Non-CMD group. Spearman correlation analysis suggested that VO2peak (r = -0.354), peak O2-pulse (r = -0.385) and VE/VCO2 slope (r = 0.294) had significant linear correlations with AccuIMR (P < 0.001). Multivariable logistic regression analysis showed that AccuIMR was the independent predictor of reduced VO2peak and elevated VE/VCO2 slope. The proportions of positive and equivocal ECG results and early O2-pulse flattening in the CMD group were significantly higher than those in the Non-CMD group, and AccuIMR was the only independent predictor of these ischemia-relating indicators, suggesting that patients with CMD had significant noninvasively detectable myocardial ischemia., (© 2024. The Author(s).)

Vertical jump height measures our ability to oppose gravity and lower body neuromuscular function in athletes and various clinical populations. Vertical jump tests are principally simple, time-efficient, and extensively used for assessing athletes and generally in sport science research. Using the force platform for jump height estimates is increasingly popular owing to technological advancements and its relative ease of use in diverse settings. However, ground reaction force data can be analyzed in multiple ways to estimate jump height, leading to distinct outcome values from the same jump. In the literature, four equations have been commonly described for estimating jump height using the force platform, where jump height can vary by up to ∼ 15 cm when these equations are used on the same jump. There are advantages and disadvantages to each of the equations according to the intended use. Considerations of (i) the jump type, (ii) the reason for testing, and (iii) the definition of jump height should ideally determine which equation to apply. The different jump height equations can lead to confusion and inappropriate comparisons of jump heights. Considering the popularity of reporting jump height results, both in the literature and in practice, there is a significant need to understand how the different mathematical approaches influence jump height. This review aims to investigate how different equations affect the assessment of jump height using force platforms across various jump types, such as countermovement jumps, squat jumps, drop jumps, and loaded jumps., Competing Interests: Declarations Author contributions Conceptualization and design: I.E., Ø.G., H.R., A.W., G.E., F.M., P.S., K.L., and G.P. Literature search: I.E., G.P., and P.S. Data interpretation: I.E., Ø.G., H.R., A.W., G.E., F.M., P.S., K.L., and G.P. Writing—original draft preparation: I.E., G.P., and Ø.G. Figures: I.E., A.W., Ø.G., and H.R. Writing—reviewing and editing: I.E., Ø.G., H.R., A.W., G.E., F.M., P.S., K.L., and G.P. All authors read and approved the final version. Funding No funding was received for the present study. Availability of data and materials Not applicable. Code availability Not applicable. Ethics approval and consent to participate: Not applicable Consent for publication Not applicable. Conflict of interest The authors declare no conflicts of interest., (© 2024. The Author(s).)

Objectives: The study aimed to establish a normative reference value for the agility T-test and Illinois test in football players, on the basis of sex and playing position., Design: Cross-sectional study., Setting: Himachal Pradesh Football Association and Maharishi Markandeshwar Medical College and Hospital-Himachal Pradesh., Participants: 138 football players including 69 male and 69 female players aged 18-25 years were included., Main Outcome Measures: Illinois and agility T-test., Results: Normative values of male and female player's are established for agility T-test 10.06 ± 0.87; 11.27 ± 0.84 and for Illinois test were 15.56 ± 0.80; 17.75 ± 1.37 s, respectively. Mann Whitney U- test was used to compare the agility of both sexes and showed a significant difference (p-value <0.001) in male and female players. Intra-rater reliability was checked for between trials and revealed excellent reliability with greatest single measure ICC (0.972) and average measure ICC (0.936) for Illinois test and single measure ICC (0.891) and average measure ICC (0.903) for agility T-test., Conclusion: Both agility tests concluded that female players are statistically and clinically less agile than male players. Similar results were found when agility was compared according to playing position. On the basis of sex, midfielders are more agile compared with other playing position., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The reliability of blood pressure (BP) measured during submaximal and maximal exercise, and confounding effects of biological sex, remain to be fully established but have implications for using exercise BP as a cardiovascular risk factor. We hypothesize that exercise BP test-retest reliability will not differ between sexes but will be higher during submaximal compared to maximal exercise. Eighty-four participants (22 ± 5 yr; 36 females) completed two maximal treadmill tests (modified Bruce protocol) separated by ≥2 days. Exercise BP was measured every 90 s using automated auscultation (Tango M2 monitor). Breath-by-breath oxygen uptake was analyzed. Test-retest reliability was assessed using two-way, mixed-effects, consistency, single-rater intraclass correlation coefficient (ICC) analysis on the total group and separated by sex at submaximal and maximal exercise. Systolic BP during submaximal (ICC = 0.65 [0.49-0.76], P < 0.01) and maximal (ICC = 0.66 [0.52-0.77], P < 0.01) exercise both displayed substantial reliability between visits. In contrast, the SBP/MET slope showed poor submaximal (ICC = 0.12 [-0.09-0.33], P = 0.13) but substantial maximal (ICC = 0.63 [0.48-0.75], P < 0.01) exercise reliability. Females showed substantial reliability in submaximal systolic BP (ICC = 0.73 [0.53-0.85], P < 0.01) and peak systolic BP (ICC = 0.74 [0.54-0.87], P < 0.01) and SBP/MET slope (ICC = 0.78 [0.60-0.88], P < 0.01); the submaximal SBP/MET slope had fair reliability (ICC = 0.28 [-0.06-0.56], P = 0.05). Males showed moderate reliability in submaximal systolic BP (ICC = 0.53 [0.26-0.72], P < 0.01) and peak systolic BP (ICC = 0.41 [0.15-0.62], P < 0.01) and SBP/MET slope (ICC = 0.48 [0.22-0.67], P < 0.01); the submaximal SBP/MET slope had poor reliability (ICC = 0.06 [-0.18-0.31], P = 0.32). Systolic BP showed similar reliability during submaximal and maximal exercise, with females demonstrating higher reliability in exercise systolic BP compared to males. NEW & NOTEWORTHY Limited work has assessed the reliability of exercise blood pressure (BP) in young healthy males and females. Our results demonstrate that systolic BP test-retest reliability did not differ between submaximal and maximal exercise. Sex-specific analysis found that females had higher reliability in exercise systolic BP than males. Despite the acceptable average reliability, exercise BP measured using automated auscultation possesses wide confidence intervals, which impact sample size requirements in future trials.

Background: Two common indications for pediatric heart transplantation are congenital heart disease and cardiomyopathy. Prior studies suggest differences in chronotropy on cardiopulmonary exercise testing outcomes depending on indication for heart transplantation. We aimed to determine whether the number of pretransplant sternotomies is associated with differences in heart rate response during exercise testing., Methods: A retrospective analysis of our institutional pediatric heart transplant data between 2004 and 2022 was performed. Patients were categorized by indication for transplantation into a cardiomyopathy (CM) group if they had a congenital or acquired cardiomyopathy or a congenital heart disease (CHD) group including all other forms of congenital cardiac anatomic abnormalities., Results: CHD patients (n = 40) differed from CM patients (n = 53) by mean number of sternotomies prior to transplant (2.4 ± 1.8 vs. 0.5 ± 0.9, p < 0.001). There were no significant differences in echocardiographic function or catheterization hemodynamics. In cardiopulmonary exercise testing performance, the congenital heart disease group had a significantly higher resting heart rate (91.8 ± 11.2 vs. 86.4 ± 10.2 bpm, p = 0.019), lower percent predicted age-predicted maximal heart rate achieved (78.3 ± 8.5% vs. 83.2 ± 11.4%, p = 0.032), and lower heart rate reserve (68.6 ± 19.8 vs. 84.4 ± 24.0 bpm, p = 0.001) despite a similar age and average time from transplantation. Regression analysis confirmed number of pretransplant sternotomies as a main predictor of heart rate metrics., Conclusions: There is greater chronotropic incompetence in patients who underwent transplantation due to congenital heart disease compared to cardiomyopathy. The groups differ significantly by number of sternotomies, potentially supporting the hypothesis that prior surgical disruption of cardiac innervation may cause decreased chronotropic response to exercise following transplantation., (© 2024 Wiley Periodicals LLC.)

Cardiac complications are the leading cause of morbidity and mortality in recipients of liver transplant (LT). Previous guidelines recommended stress testing to exclude coronary artery disease (CAD), although recent guidelines recommend coronary computed tomography angiography (CCTA). We aimed to assess the prevalence and predictors of CAD on CCTA and compare CCTA with stress testing in consecutive adult candidates for LT who underwent CAD noninvasive assessment between 2020 and 2023. Patients who underwent a stress test between January and December 2020 formed the stress cohort, and patients who underwent CCTA between January 2021 and September 2023 formed the CCTA cohort. There were 141 patients in the stress test cohort and 269 patients in the CCTA cohort. Stress test results were nondiagnostic or inconclusive in 18 patients (12.8%) whereas CCTA was nondiagnostic in 6 patients (2.2%). In patients evaluated with CCTA, mean coronary artery calcium (CAC) score was 332 ± 716 AU, with moderate or greater (>50%) stenosis in 33 patients (12.3%). New CAD was diagnosed in 158 patients (58.7%) using CCTA and in 5 patients (3.5%) using stress tests. Clinically actionable CAD (coronary artery calcium >100) on CCTA was present in 96 patients (35.7%). The number of CAD risk factors was associated with the presence of CAD on CCTA. In conclusion, there was a great burden of CAD, mainly nonobstructive, in a large cohort of candidates for LT who underwent CAD testing over a 4-year period. The current recommended risk-based evaluation of candidates for LT using CCTA as a first-line test was feasible and effective. Diagnosis of clinically actionable CAD on CCTA provides a vast opportunity for optimizing cardiac care in candidates for and recipients of LT., Competing Interests: Declaration of competing interest The authors have no competing interest to declare., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Cerebral hemodynamics have been quantified during exercise via transcranial Doppler ultrasound, as it has high-sensitivity to movement artifacts and displays temporal superiority. Currently, limited research exists regarding how different exercise modalities and postural changes impact the cerebrovasculature across the cardiac cycle. Ten participants (4 females and 6 males) ages 20-29 completed three exercise tests (treadmill, supine, and upright cycling) to volitional fatigue. Physiological data collected included middle cerebral artery velocity (MCAv), blood pressure (BP), heart rate, and respiratory parameters. Normalized data were analyzed for variance and effect sizes were calculated to examine differences between physiological measures across the three exercise modalities. Systolic MCAv was greater during treadmill compared to supine and upright cycling ( p  < 0.001, (large) effect size), and greater during upright versus supine cycling ( p  < 0.017, (large)). Diastolic MCAv was lower during treadmill versus cycling exercise only at 60% maximal effort ( p  < 0.005, (moderate)) and no differences were observed between upright and supine cycling. No main effect was found for mean and diastolic BP ( p  > 0.05, (negligible)). Systolic BP was lower during treadmill versus supine cycling at 40% and 60% intensity ( p  < 0.05, (moderate-large)) and greater during supine versus upright at only 60% intensity ( p  < 0.003, (moderate)). The above differences were not explained by partial pressure of end-tidal carbon dioxide levels (main effect: p  = 0.432) . The current study demonstrates the cerebrovascular and cardiovascular systems respond heterogeneously to different exercise modalities and aspects of the cardiac cycle. As physiological data were largely similar between tests, differences associated with posture and modality are likely contributors., Competing Interests: The authors declare they have no conflicts of interest.

Background: Myocardial perfusion SPECT (MPS) and exercise electrocardiography (Ex-ECG) results are of prognostic importance for short-term follow up duration. However, the value of MPS or Ex-ECG findings for long-term risk assessment is less evident as underlying risk factors for ischemic heart disease (IHD) gain in importance., Objectives: To assess the short- and long-term prognostic value of MPS and Ex-ECG in relation to known risk factors., Methods and Materials: An observational study of 908 patients (age 63 years, 49% male, 45% prior IHD) referred for MPS and Ex-ECG. Follow-up was divided into two periods (short-term: <5 years and long-term: >5 years). Cardiac events were defined as a composite of acute myocardial infarction, unstable angina, unplanned revascularization and cardiovascular death., Results: The composite endpoint occurred in 95 patients (short-term follow up) and in 94 patients (long-term follow up). In multivariable models stress testing had a strong predictive value for short-term follow up (HR for MPS = 2.9, CI = 1.9-4.5, p < 0.001 and HR for Ex-ECG = 2.1, CI 1.3-3.3, p = 0.002), but no predictive value for long-term follow up (HR for MPS = 0.9, CI = 0.5-1.5, p = 0.70 and HR for Ex-ECG = 1.0, CI = 0.6-1.6, p = 0.92). Male sex and prior IHD were significant predictors regardless of follow up duration. Age, diabetes and decreased exercise capacity were risk factors for long-term follow up., Conclusions: The prognostic value of MPS and Ex-ECG results are strong for short-term follow up but diminish over time and do not contribute significantly in multivariable models after 5 years. Long-term prognosis is primarily governed by underlying risk factors and exercise capacity., (© 2024 The Author(s). Clinical Physiology and Functional Imaging published by John Wiley & Sons Ltd on behalf of Scandinavian Society of Clinical Physiology and Nuclear Medicine.)

Purpose: We studied the effect of O 2 supplementation on physiological response to exercise in patients with moderate to severe interstitial lung disease (ILD)., Methods: Thirteen patients (age 66 ± 10 yr, 7 males) with ILD (total lung capacity, 71% ± 22% predicted; carbon monoxide diffusion capacity, 44% ± 16% predicted) and 13 healthy individuals (age 50 ± 17 yr, 7 males) were tested. ILD patients performed symptom-limited cardiopulmonary exercise tests and constant work rate (WR) tests at 80% of the WR at the gas exchange threshold. Tests breathing room air (RA; 21% O 2 ) were compared with tests performed breathing 30% O 2 . Oxygen uptake (V̇O 2 ) kinetics were calculated from the constant WR test results., Results: In the ILD group, peak WR, peak V̇O 2 , and V̇O 2 at the gas exchange threshold improved significantly when breathing 30% O 2 compared with RA (mean ± SD, 75 ± 26 vs 66 ± 23 W, 17 ± 4 vs 15 ± 2 mL·kg -1 ·min -1 , and 932 ± 245 vs 854 ± 232 mL·min -1 ; P = 0.004, P = 0.001, and P = 0.01, respectively). O 2 saturation (SpO 2 %) at peak exercise was higher with 30% O 2 (97% ± 4% vs 88% ± 9%, P = 0.002). The time constant (tau) of V̇O 2 kinetics was faster in ILD patients while breathing 30% O 2 (41 ± 10 s) compared with RA (52 ± 14 s, P = 0.003). There was a negative linear relation between tau and SpO 2 % with RA ( r = -0.76, P = 0.006) and while breathing 30% O 2 ( r = -0.68, P = 0.02)., Conclusions: Using a clinically applicable level of O 2 supplementation (30%) improved maximal, aerobic exercise capacity and V̇O 2 kinetics in ILD patients, likely due to increased blood O 2 content subsequently increasing the O 2 delivery to the working muscles., (Copyright © 2024 by the American College of Sports Medicine.)

The exercise stress testing may unmask the type 1 Brugada pattern on the surface electrocardiogram in a portion of patients with Brugada syndrome. The occurrence of the type 1 Brugada pattern during an exercise test in pediatric patients is not common. Consequently, the diagnostic yield of the exercise test in this population is still to be explored. We present a case of exercise-induced type 1 Brugada pattern in a 12-year-old child with episodes of palpitations and discuss the available evidence on the role of the exercise stress test in the diagnosis and risk stratification of patients with Brugada syndrome., (© 2024 Wiley Periodicals LLC.)

Background: Cardiopulmonary exercise testing (CPET) is a preoperative risk stratification tool providing an objective measure of fitness and functional capacity. There is however little evidence on the use of this compared to non-physiological test in vascular surgery despite its current use. This study investigates whether CPET perioperatively has value alongside non-physiological testing for patients undergoing elective open abdominal aortic aneurysm (AAA) repair., Method: Retrospective data was collected at 2 vascular centres between 2015-2019 in a CPET centre vs non-CPET centre in patients undergoing elective AAA repair. Outcomes measured included: length of stay in an intensive care unit (ICU); total length of stay; post-operative complications and acute kidney injury (AKI). Statistical analysis was performed using IBM SPSS software., Results: There were 38 patients at each centre. The mean duration of stay in ICU for patients in CPET centre was 2.5 ± 2.13 days whilst in non-CPET centre it was 3.68 ± 4.08 days ( P = 0.05). The mean duration of stay in ICU and total length of stay was significantly shorter in CPET centre ( P = 0.05 and P = 0.015 respectively). Mortality in CPET centre was 2.63% and 5.26% in non-CPET centre (not significant). The number of patients developing AKI post-operatively was 13.61% in CPET vs 28.95% in non-CPET centre., Conclusion: CPET tested patients have statistically significant lower length of total and ICU stay compared to non-CPET patients. CPET is therefore a useful adjunct in selecting patients for open surgery compared to non-physiological testing. This study provides some evidence on the use of this routinely but not validated assessment tool in aortic aneurysm repair., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Objective: Providing an overview of the clinimetric properties of the steep ramp test (SRT)-a short-term maximal exercise test-to assess cardiorespiratory fitness (CRF), describing its underlying physiological responses, and summarizing its applications in current clinical and research practice., Data Sources: MEDLINE (through PubMed), CINAHL Complete, Cochrane Library, EMBASE, and PsycINFO were searched for studies published up to July 2023, using keywords for SRT and CRF., Study Selection: Eligible studies involved the SRT as research subject or measurement instrument and were available as full text articles in English or Dutch., Data Extraction: Two independent assessors performed data extraction. Data addressing clinimetric properties, physiological responses, and applications of the SRT were tabulated., Data Synthesis: In total, 370 studies were found, of which 39 were included in this study. In several healthy and patient populations, correlation coefficients between the work rate at peak exercise (WR peak ) attained at the SRT and oxygen uptake at peak exercise during cardiopulmonary exercise testing (CPET) ranged from .771-.958 (criterion validity). Repeated measurements showed intraclass correlation coefficients ranging from .908-.996 for WR peak attained with the first and second SRT (test-retest reliability). Physiological parameters, like heart rate and minute ventilation at peak exercise, indicated that the SRT puts a lower burden on the cardiopulmonary system compared to CPET. The SRT is mostly used to assess CRF, among others as part of preoperative risk assessment, and to personalize interval training intensity., Conclusions: The SRT is a practical short-term maximal exercise test that is valid for CRF assessment and to monitor changes in CRF over time in various healthy and patient populations. Its clinimetric properties and potential applications make the SRT of interest for a widespread implementation of CRF assessment in clinical and research practice and for personalizing training intensity and monitoring longitudinal changes in CRF., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Objective: To improve preoperative risk stratification in lung cancer lobectomy by identifying and comparing optimal thresholds for peak oxygen uptake (VO 2peak ) presented as weight-indexed and percent of predicted values, respectively., Methods: This was a longitudinal cohort study including national registry data on patients scheduled for cancer lobectomy that used available data from preoperative cardiopulmonary exercise testing. The measured VO 2peak was indexed by body mass (mL/kg/min) and also compared with 2 established reference equations (Wasserman-Hansen and Study of Health in Pomerania, respectively). By receiver operating characteristic analysis, a lower 90% specificity and an upper 90% sensitivity threshold were determined for each measure, in relation to the outcome of any major complication or death. For each measure and based on these thresholds, patients were categorized as low risk, intermediate risk, or high risk. The frequency of complications was compared between groups using χ 2 ., Results: The frequency of complications differed significantly between the proposed low-, intermediate-, and high-risk groups when using % predicted Study of Health in Pomerania (5%, 21%, 35%, P = .007) or % predicted Wasserman-Hansen (5%, 25%, 35%, P = .002) but not when using the weight-indexed VO 2peak groups (7%, 23%, 15%, P = .08). Nonsignificant differences were found using the threshold <15 mL/kg/min (P = .34)., Conclusions: This study showed that weight-indexed VO 2peak was of less use as a marker of risk at the lower range of exercise capacity, whereas % predicted VO 2peak was associated with a continuously increasing risk of major complications, also at the lower end of exercise capacity. As identifying subjects at high risk of complications is important, % predicted VO 2peak is therefore preferable., Competing Interests: Conflict of Interest Statement The authors reported no conflicts of interest. The Journal policy requires editors and reviewers to disclose conflicts of interest and to decline handling or reviewing manuscripts for which they may have a conflict of interest. The editors and reviewers of this article have no conflicts of interest., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Purpose: This study reports the results of a 20-yr (2005 to 2024) follow-up study of two 2-time Olympic and 6-time world champion rowing athletes. To provide a comprehensive picture of adaptations in physiological and performance characteristics to long-term training, we monitored the athletes' physiological and performance data annually through five 4-yr developmental phases., Methods: Maximal oxygen uptake (V̇O 2max ), maximal minute power (MMP), and power output corresponding to anaerobic threshold (PAT) were derived from a rampwise exercise test on a rowing ergometer. In addition, average power output sustained during all-out tests over 2000 and 6000 m on a rowing ergometer was also obtained., Results: V̇O 2max peaked at age 22 for athlete A and at age 25 for athlete B (at ~7 L·min -1 ) before stabilizing and then gradually declining to a range of 6.2 to 6.5 L·min -1 for both athletes. MMP stabilized in both rowers at values between 550 and 575 W and displayed minimal fluctuations over the final two phases of the study. In addition, MMP closely resembled the corresponding average power output sustained during the 2000-m all-out tests on a rowing ergometer. Average power output during 2000 and 6000-m all-out tests showed steady improvements over the monitored phases of the study, with the highest power output crew averages for both 2000-m (532 W; 5 min 48 s) and 6000-m (463 W; 18 min 4 s) tests recorded during the last 4-yr phase of the assessment., Conclusions: Improvements in rowing ergometer performance over 2000 and 6000 m appear to be largely independent of the multiyear changes in V̇O 2max . Long-term rowing training resulted in continuous improvements in MMP and PAT throughout the monitored phases, which more closely mimicked improvements in rowing ergometer performance., (Copyright © 2024 by the American College of Sports Medicine.)

Background: In patients with chronic obstructive pulmonary disease (COPD), the clinical use of the minute ventilation-carbon dioxide production ([Formula: see text] E -[Formula: see text] CO2 ) slope has been reported as a measure of exercise efficiency, but the oxygen uptake efficiency slope (OUES), i.e., the slope of oxygen uptake ([Formula: see text] O2 ) versus the logarithmically transformed [Formula: see text] E , has rarely been reported., Methods: We hypothesized that the [Formula: see text] E -[Formula: see text] CO2 slope is more useful than OUES in clinical use for the pathophysiological evaluation of COPD. Then, we investigated the cardiopulmonary exercise testing parameters affecting each of these slopes in 122 patients with all Global Initiative for Chronic Obstructive Lung Disease (GOLD) COPD grades selected from our database., Results: Compared with the GOLD I-II group (n = 51), peak [Formula: see text] O2 (p < 0.0001), OUES (p = 0.0161), [Formula: see text] E at peak exercise (p < 0.0001), and percutaneous oxygen saturation (SpO 2 ) at peak exercise (p = 0.0004) were significantly lower in the GOLD III-IV group (n = 71). The GOLD III-IV group was divided into two groups by the exertional decrease in SpO 2 from rest to peak exercise: 3% or less (the non-desaturation group: n = 23), or greater than 3% (the desaturation group: n = 48). OUES correlated only weakly with peak [Formula: see text] O2 , [Formula: see text] E at peak exercise, and the difference between inspired and expired mean O 2 concentrations (ΔF O2 ) at peak exercise, i.e., an indicator of oxygen consumption ability throughout the body, in the GOLD III-IV group with exertional hypoxemia. In contrast, the [Formula: see text] E -[Formula: see text] CO2 slope was significantly correlated with ΔF O2 at peak exercise, regardless of the COPD grade and exertional desaturation. Across all COPD stages, there was no correlation between the [Formula: see text] E -[Formula: see text] CO2 slope and [Formula: see text] E at peak exercise, and stepwise analysis identified peak [Formula: see text] O2 (p = 0.0345) and ΔF O2 (p < 0.0001) as variables with a greater effect on the [Formula: see text] E -[Formula: see text] CO2 slope., Conclusions: The OUES may be less useful in advanced COPD with exertional hypoxemia. The [Formula: see text] E -[Formula: see text] CO2 slope, which is independent of [Formula: see text] E , focuses on oxygen consumption ability and exercise tolerance in COPD, regardless of the exertional hypoxemia level and COPD grade. Therefore, the [Formula: see text] E -[Formula: see text] CO2 slope might be useful in establishing or evaluating tailor-made therapies for individual patient's pathologies in COPD as an indicator focusing on oxygen consumption ability., (© 2024. The Author(s).)

Hypertension is a fatal but preventable risk factor for cardiovascular disease and an important cause of death from cardiovascular disease. Exercise training has a definite clinical effect on blood pressure control. However, inappropriate exercise is ineffective and may also cause disease. The aim of this study was to evaluate the possible factors influencing blood pressure level in an exercise treadmill test and its relationship with accompanying clinical diseases. Five hundred sixty-four patients who underwent exercise treadmill test were selected and divided into the abnormal exercise blood pressure group (n = 156, age 60.46 ± 9.2 years) and normal exercise blood pressure group (n = 408, age 56.57 ± 8.8 years) according to whether the peak exercise systolic blood pressure was more than or equal to 180 mm Hg. General clinical data and associated clinical diseases were collected from both groups. The prevalence of hypertension and coronary atherosclerotic heart disease in the abnormal exercise blood pressure group was significantly higher than that in the normal exercise blood pressure group (all P < .05). At the same time, the smoking rate and glycohemoglobin level of the patients with abnormal exercise blood pressure were significantly increased (all P < .05), but there was no statistically significant difference in age, sex, body mass index, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and other indicators between the 2 groups (all P > .05). Patients with abnormal exercise blood pressure response have a higher prevalence of hypertension and coronary heart disease. Exercise blood pressure level may be an important factor affecting patients' cardiovascular prognosis., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

Competing Interests: Conflict of interest: none declared.

Background and Objectives: Few comparative studies have evaluated wearable single-lead electrocardiogram (ECG) devices and standard multi-lead ECG devices during exercise testing. This study aimed to validate the accuracy of a wearable single-lead ECG monitor for recording heart rate (HR) metrics during graded exercise tests (GXTs)., Methods: A cohort of 50 patients at a tertiary hospital underwent GXT while simultaneously being equipped with wearable single- and conventional multi-lead ECGs. The concordance between these modalities was quantified using the intraclass correlation coefficient and Bland-Altman plot analysis., Results: The minimum and average HR readings between the devices were generally consistent. Parameters such as ventricular ectopic beats and supraventricular ectopic beats showed strong agreement. However, the agreement for the Total QRS and Maximum RR was not sufficient. HR measurements across different stages of the exercise test showed sufficient agreement. Although not statistically significant, the standard multi-lead ECG devices exhibited higher noise levels compared to the wearable single-lead ECG devices., Conclusions: Wearable single-lead ECG devices can reliably monitor HR and detect abnormal beats across a spectrum of exercise intensities, offering a viable alternative to traditional multi-lead systems.

Purpose: The objective of this study was to investigate the role of myocardial perfusion imaging (MPI) stress tests using stress cardiac magnetic resonance (sCMR) and single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI) in non-cardiac surgery (NCS) pre-operatory management., Materials and Methods: This monocentric retrospective study enrolled patients with coronary artery disease or a minimum of two cardiovascular risk factors undergoing intermediate-to-high-risk non-cardiac surgeries. The primary composite endpoint comprised cardiac death, cardiogenic shock, acute coronary syndromes (ACS), and cardiogenic pulmonary edema occurring within 30 days after surgery, while the secondary endpoint was ACS., Results: A total of 1590 patients were enrolled; among them, 669 underwent a MPI stress test strategy (sCMR: 287, SPECT-MPI: 382). The incidence of 30-day cardiac events was lower in the stress-tested group compared to the non-stress-tested group (1.2% vs. 3.4%; p 0.006). Adopting a stress test strategy showed a significant reduction in the risk of the composite endpoint (OR: 0.33, 95% CI: 0.15-0.76, p 0.009) and ACS (OR: 0.41, 95% CI: 0.17-0.98, p 0.046) at multivariable analysis, with similar cardiac events rate between stress CMR and SPECT (1.1% vs. 1.3%, p 0.756). Stress CMR showed a greater accuracy to predict coronary artery revascularizations (sCMR c-statistic: 0.95, ischemic cut-point: 5.5%; SPECT c-statistic: 0.85, ischemic cut-point: 7.5%)., Conclusion: Stress test strategy is related to a lower occurrence of cardiac events in high-risk patients scheduled for intermediate-to-high-risk non-cardiac surgeries. Both sCMR and SPECT-MPI comparably reduce the likelihood of cardiac complications, albeit sCMR offers greater accuracy in predicting coronary artery revascularization., (© 2024. The Author(s).)

Despite exercise intolerance being predictive of outcomes in pulmonary arterial hypertension (PAH), its underlying cardiac mechanisms are not well described. The aim of the study was to explore the biventricular response to exercise and its associations with cardiorespiratory fitness in children with PAH. Participants underwent incremental cardiopulmonary exercise testing and simultaneous exercise echocardiography on a recumbent cycle ergometer. Linear mixed models were used to assess cardiac function variance and associations between cardiac and metabolic parameters during exercise. Eleven participants were included with a mean age of 13.4 ± 2.9 yr old. Right ventricle (RV) systolic pressure (RVsp) increased from a mean of 59 ± 25 mmHg at rest to 130 ± 40 mmHg at peak exercise ( P < 0.001), whereas RV fractional area change (RV-FAC) and RV-free wall longitudinal strain (RVFW-S l ) worsened (35.2 vs. 27%, P = 0.09 and -16.6 vs. -14.6%, P = 0.1, respectively). At low- and moderate-intensity exercise, RVsp was positively associated with stroke volume and O 2 pulse ( P < 0.1). At high-intensity exercise, RV-FAC, RVFW-S l , and left ventricular longitudinal strain were positively associated with oxygen uptake and O 2 pulse ( P < 0.1), whereas stroke volume decreased toward peak ( P = 0.04). In children with PAH, the increase of pulmonary pressure alone does not limit peak exercise, but rather the concomitant reduced RV functional reserve, resulting in RV to pulmonary artery (RV-PA) uncoupling, worsening of interventricular interaction and LV dysfunction. A better mechanistic understanding of PAH exercise physiopathology can inform stress testing and cardiac rehabilitation in this population. NEW & NOTEWORTHY In children with pulmonary arterial hypertension, there is a marked increase in pulmonary artery pressure during physical activity, but this is not the underlying mechanism that limits exercise. Instead, right ventricle-to-pulmonary artery uncoupling occurs at the transition from moderate to high-intensity exercise and correlates with lower peak oxygen uptake. This highlights the more complex underlying pathological responses and the need for multiparametric assessment of cardiac function reserve in these patients when feasible.

Purpose: This study aimed to analyze the shared genetic background of physical fitness tests in children., Methods: Physical fitness was assessed in 198 Portuguese twin pairs (6-18 yr old, 40% monozygotic) through 15 tests from the Eurofit and Fitnessgram test batteries. Genetic twin modeling was used to estimate the heritability of each test and the genetic correlations between them., Results: Girls performed better than boys in flexibility, whereas boys performed better than girls in cardiorespiratory endurance and muscular strength. No sex differences were found in the influence of genetic factors on the physical fitness tests or their mutual correlations. Genetic factors explained 52% (standing long jump) to 79% (sit and reach) of the individual variation in motor performance, whereas individual-specific environmental factors explained the remaining variation. Most of the tests showed modest to moderate genetic correlations. Out of all 105 genetic correlations, 65% ranged from 0.2 to 0.6 indicating that they shared from 4% to 36% of genetic variation. The correlations between individual-specific environmental factors were mostly negligible., Conclusions: Tests measuring the strength of different muscle groups showed only modest correlations, but moderate correlations were found between tests measuring explosive strength, running speed/agility, and cardiorespiratory endurance. Genetic factors explained a major portion of the variation in tests included in the Eurofit and Fitnessgram test batteries and explained the correlations between them. The modest to moderate genetic correlations indicated that there is little redundancy of tests in either Eurofit or Fitnessgram test batteries., (Copyright © 2024 by the American College of Sports Medicine.)

Background: Studies have shown a positive relationship between cardiorespiratory fitness (CRF) and executive functioning in older adults. Although this relationship has been well established, there seems to be a gap in the literature on the role of sex differences concerning CRF and executive functions. The current study aimed to assess the effect of sex in the relationship between CRF and cognition in older adults by stratifying the results to examine effects in males and females., Methods: Ninety-six older adults (61 females) gave their written, informed consent to participate in this cross-sectional study. All participants underwent a maximal continuous graded exercise test on a cycle ergometer to assess their maximal oxygen uptake (VO2max) and a computerized Stroop task (naming, inhibition, and switching) to assess their executive functions. According to VO2max test results and the American College of Sports Medicine's guidelines, females and males were classified into higher-fit and lower-fit groups. A general linear model and estimated marginal means analyses were applied., Results: Results showed no significant differences in the naming, inhibition and switching performance tests between male and female older adults (P>0.05)., Conclusions: Based on the observed positive relationship between CRF and executive functioning, the data of the current study supports the idea that aerobic exercise, which typically increases CRF, is well-situated to improve executive functioning in older adults, irrespective of sex.

Purpose: Ventilatory constraints are common during exercise in children, but the effects of obesity and sex are unclear. The purpose of this study was to investigate the effects of obesity and sex on ventilatory constraints (i.e., expiratory flow limitation (EFL) and dynamic hyperinflation) during a maximal exercise test in children., Methods: Thirty-four 8- to 12-yr-old children without obesity (18 females) and 54 with obesity (23 females) completed pulmonary function testing and maximal cardiopulmonary exercise tests. EFL was calculated as the overlap between tidal flow-volume loops during exercise and maximal expiratory flow-volume loops. Dynamic hyperinflation was calculated as the change in inspiratory capacity from rest to exercise., Results: Maximal minute ventilation was not different between children with and without obesity. Average end-inspiratory lung volumes (EILV) and end-expiratory lung volumes (EELV) were significantly lower during exercise in children with obesity (EILV: 68.8% ± 0.7% TLC; EELV: 41.2% ± 0.5% TLC) compared with children without obesity (EILV: 73.7% ± 0.8% TLC; EELV: 44.8% ± 0.6% TLC; P < 0.001). Throughout exercise, children with obesity experienced more EFL and dynamic hyperinflation compared with those without obesity ( P < 0.001). Also, males experienced more EFL and dynamic hyperinflation throughout exercise compared with females ( P < 0.001). At maximal exercise, the prevalence of EFL was similar in males with and without obesity; however, the prevalence of EFL in females was significantly different, with 57% of females with obesity experiencing EFL compared with 17% of females without obesity ( P < 0.05). At maximal exercise, 44% of children with obesity experienced dynamic hyperinflation compared with 12% of children without obesity ( P = 0.002)., Conclusions: Obesity in children increases the risk of developing mechanical ventilatory constraints such as dynamic hyperinflation and EFL. Sex differences were apparent with males experiencing more ventilatory constraints compared with females., (Copyright © 2024 by the American College of Sports Medicine.)

The Fontan procedure results in chronic hepatic congestion and Fontan-associated liver disease (FALD) characterized by progressive liver fibrosis and cirrhosis. Exercise is recommended in this population, but may accelerate the progression of FALD from abrupt elevations in central venous pressure. The aim of this study was to assess if acute liver injury occurs after high-intensity exercise in patients with Fontan physiology. Ten patients were enrolled. Nine had normal systolic ventricular function and one had an ejection fraction < 40%. During cardiopulmonary exercise testing, patients had near-infrared spectroscopy (NIRS) to measure oxygen saturation of multiple organs, including the liver, and underwent pre- and post-exercise testing with liver elastography, laboratory markers, and cytokines to assess liver injury. The hepatic and renal NIRS showed a statistically significant decrease in oxygenation during exercise, and the hepatic NIRS had the slowest recovery compared to renal, cerebral, and peripheral muscle NIRS. A clinically significant increase in shear wave velocity occurred after exercise testing only in the one patient with systolic dysfunction. There was a statistically significant, albeit trivial, increase in ALT and GGT after exercise. Fibrogenic cytokines traditionally associated with FALD did not increase significantly in our cohort; however, pro-inflammatory cytokines that predispose to fibrogenesis did significantly rise during exercise. Although patients with Fontan circulation demonstrated a significant reduction in hepatic tissue oxygenation based on NIRS saturations during exercise, there was no clinical evidence of acute increase in liver congestion or acute liver injury following high-intensity exercise., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Cancer survivors exposed to anthracycline chemotherapy are at risk for developing cardiomyopathy, which may have delayed clinical manifestation. In a retrospective cross-sectional study, we evaluated the utility of cardiopulmonary exercise testing (CPET) for detecting early cardiac disease in 35 pediatric cancer survivors by examining the associations between peak exercise capacity (measured via percent predicted peak VO 2 ) and resting left ventricular (LV) function on echocardiography and cardiac magnetic resonance imaging (cMRI). We additionally assessed the relationships between LV size on resting echocardiography or cMRI and percent predicted peak VO 2 since LV growth arrest can occur in anthracycline-exposed patients prior to changes in LV systolic function. We found reduced exercise capacity in this cohort, with low percent predicted peak VO 2 (62%, IQR: 53-75%). While most patients in our pediatric cohort had normal LV systolic function, we observed associations between percent predicted peak VO 2 and echocardiographic and cMRI measures of LV size. These findings indicate that CPET may be more sensitive in manifesting early anthracycline-induced cardiomyopathy than echocardiography in pediatric cancer survivors. Our study also highlights the importance of assessing LV size in addition to function in pediatric cancer survivors exposed to anthracyclines., (© 2023. The Author(s).)

Objectives: Paradoxical associations between high occupational physical activity (OPA) and cardiovascular disease may be explained by exaggerated cardiovascular responses from high work-related stress or low worker fitness., Methods: OPA, blood pressure (BP), heart rate (HR), and rate-pressure product (RPP; HR × BP) were measured objectively for 24 hours in 19 male workers. Work-related stress was measured using the Stress in General Scale. Fitness was estimated using a submaximal treadmill test. Effect modification by work-related stress and fitness on associations between OPA and cardiovascular responses was examined using mixed models with interactions., Results: Associations between OPA and RPP, HR, and BP were stronger with high stress ( P < 0.05). Associations of work-time moderate and vigorous physical activity and RPP were attenuated with higher fitness ( P < 0.05)., Conclusions: OPA performed under high work-related stress or by workers with low fitness may exaggerate cardiovascular responses to OPA., Competing Interests: Conflict of Interest: None declared., (Copyright © 2024 American College of Occupational and Environmental Medicine.)

Background: Evidence regarding the performance-related effects of Actovegin is limited, despite legislated restrictions being in place for this supplement within sport settings., Objectives: Our study examined the effects of Actovegin on physiological responses and performance during maximal cardiopulmonary exercise in collegiate athletes., Methods: A randomized, double-blind, placebo-controlled experimental design was adopted. Moderately trained collegiate athletes from various sports were randomly allocated to placebo ( n = 8) or Actovegin ( n = 8) groups. All athletes consumed three capsules across each day for seven days of loading. Athletes underwent two separate cardiopulmonary exercise tests one week apart. Separate 2 × 2 mixed ANOVAs and effect sizes (ηp2) were used to assess for between- and within-group differences., Results: A significant time * group effect ( p = 0.036, ηp2 = 0.278) was observed in systolic blood pressure. Significant main effects were only observed for time in several variables, with increases in peak oxygen uptake (VO 2 ) ( p < 0.001, ηp2 = 0.893), peak minute ventilation ( p = 0.004, ηp2 = 0.456), ventilatory equivalents for carbon dioxide ( p = 0.002, ηp2 = 0.517), oxygen pulse ( p = 0.006, ηp2 = 0.434), VO 2 at first ventilatory threshold ( p = 0.002, ηp2 = 0.520), velocity at second ventilatory threshold ( p < 0.001, ηp2 = 0.997), VO 2 at second ventilatory threshold ( p < 0.001, ηp2 = 0.628), and peak velocity ( p = 0.010, ηp2 = 0.386), and a decrease in respiratory exchange ratio ( p < 0.001, ηp2 = 0.695)., Conclusions: Our findings suggest that although physiological and performance alterations were evident with Actovegin supplementation during cardiopulmonary exercise, no further benefits beyond those obtained with a placebo were attained.

Objective: To investigate the changes in cardiopulmonary exercise testing (CPET) characteristics before and after the outbreak of COVID-19 in patients with acute coronary syndrome (ACS) who underwent percutaneous coronary intervention (PCI). Methods: This is a cross-sectional study that included ACS patients who underwent PCI at the General Hospital of the Northern Theater Command from July 2018 to February 2023. Based on the timeline of the COVID-19 pandemic, patients were divided into two groups: the pre-pandemic group and the during-pandemic group, with January 2020 as the dividing line. Clinical data were collected from both groups, and a comparative analysis was performed on their postoperative CPET outcomes, including peak oxygen uptake (peak VO 2 ), peak metabolic equivalents (peak MET), and other indicators. Weber's classification was used to assess cardiac function. In addition, the 7-tiem generalized anxiety disorder scale (GAD-7) and the patient health questionnaire-9 (PHQ-9) were used to assess the patients' psychological anxiety and depression states, respectively. Multivariate logistic regression was used to analyze the influencing factors of CPET after PCI. Results: A total of 4 310 post-PCI ACS patients were included, with an average age of (58.7±9.1) years, and 3 464 (80.37%) were male. There were 1 698 patients in the pre-pandemic group and 2 612 patients in the during-pandemic group. The main indicator of the CPET, peak VO 2 (15.04±3.93) ml·min -1 ·kg -1 in the during-pandemic group, was lower than that in the pre-pandemic group (15.52±3.68) ml·min -1 ·kg -1 , and the difference was statistically significant ( P <0.001). Multivariate logistic regression analysis showed that advanced age, female gender, high body mass index, elevated high-sensitivity C-reactive protein, reduced high-density lipoprotein cholesterol, smoking history, history of myocardial infarction, more severe ACS classification, and mild to moderate degree of depression were related to poor cardiopulmonary outcomes ( P <0.05). Conclusion: The COVID-19 pandemic had a negative impact on the cardiopulmonary outcomes of ACS patients after PCI. Reduced physical activity, and increased psychological stress should be given consideration and attention regarding their impact on patients' cardiopulmonary function.

Objective: Routine screening for cardiovascular disease before kidney transplantation remains controversial. This study aims to compare cardiac testing rates in patients with end-stage renal disease, referred and not referred for transplantation, and assess the impact of testing on transplant wait times., Methods: This is a retrospective cohort study of 22 687 end-stage renal disease patients from 2011 to 2022, within an integrated health system. Cardiac testing patterns, and the association between cardiac testing and transplant wait times and post-transplant mortality were evaluated., Results: Of 22 687 patients (median age 66 years, 41.1% female), 6.9% received kidney transplants, and 21.0% underwent evaluation. Compared with dialysis patients, transplant patients had a 5.6 times higher rate of stress nuclear myocardial perfusion imaging with single-photon emission (rate ratio (RR) 5.64, 95% CI 5.37 to 5.92), a 6.5 times higher rate of stress echocardiogram (RR 6.51, 95% CI 5.65 to 7.51) and 16% higher cardiac catheterisation (RR 1.16, 95% CI 1.06 to 1.27). In contrast, revascularisation rates were significantly lower in transplant patients (RR 0.46, 95% CI 0.36 to 0.58). Transplant wait times were longer for patients who underwent stress testing (median 474 days with no testing vs 1053 days with testing) and revascularisation (1796 days for percutaneous intervention and 2164 days for coronary artery bypass surgery). No significant association was observed with 1-year post-transplant mortality (adjusted OR 1.99, 95% CI 0.46 to 8.56)., Conclusions: This study found a higher rate of cardiac testing in dialysis patients evaluated for kidney transplants. Cardiac testing was associated with longer transplant wait time, but no association was observed between testing and post-transplant mortality., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Competing Interests: Conflict of interest: A.R.T. has participated in advisory boards for Janssen and Merck Pharmaceuticals. All other authors have no financial conflicts.

Understanding the changes in running mechanics caused by fatigue is essential to assess its impact on athletic performance. Changes in running biomechanics after constant speed conditions are well documented, but the adaptive responses after a maximal incremental test are unknown. We compared the spatiotemporal, joint kinematics, elastic mechanism, and external work parameters before and after a maximal incremental treadmill test. Eighteen recreational runners performed 2-minute runs at 8 km·h-1 before and after a maximal incremental test on a treadmill. Kinematics, elastic parameters, and external work were determined using the OpenCap and OpenSim software. We did not find differences in spatiotemporal parameters and elastic parameters (mechanical work, ankle, and knee motion range) between premaximal and postmaximal test conditions. After the maximal test, the runners flexed their hips more at contact time (19.4°-20.6°, P = .013) and presented a larger range of pelvis rotation at the frontal plane (10.3°-11.4°, P = .002). The fatigue applied in the test directly affects pelvic movements; however, it does not change the lower limb motion or the spatiotemporal and mechanical work parameters in recreational runners. A larger frontal plane motion of the pelvis deserves attention due to biomechanical risk factors associated with injuries.

Cardiopulmonary exercise testing (CPET) is a comprehensive and invaluable assessment used to identify the mechanisms that limit exercise capacity. However, its interpretation remains poorly standardised. This scoping review aims to investigate which limitations to exercise are differentiated by the use of incremental CPET in literature and which criteria are used to identify them. We performed a systematic, electronic literature search of PubMed, Embase, Cochrane CENTRAL, Web of Science and Scopus. All types of publications that reported identification criteria for at least one limitation to exercise based on clinical parameters and CPET variables were eligible for inclusion. 86 publications were included, of which 57 were primary literature and 29 were secondary literature. In general, at the level of the cardiovascular system, a distinction was often made between a normal physiological limitation and a pathological one. Within the respiratory system, ventilatory limitation, commonly identified by a low breathing reserve, and gas exchange limitation, mostly identified by a high minute ventilation/carbon dioxide production slope and/or oxygen desaturation, were often described. Multiple terms were used to describe a limitation in the peripheral muscle, but all variables used to identify this limitation lacked specificity. Deconditioning was a frequently mentioned exercise limiting factor, but there was no consensus on how to identify it through CPET. There is large heterogeneity in the terminology, the classification and the identification criteria of limitations to exercise that are distinguished using incremental CPET. Standardising the interpretation of CPET is essential to establish an objective and consistent framework., Competing Interests: Conflict of interest: I. Gyselinck reports grants from Research Foundation Flanders, and support for attending meetings from AstraZeneca. W. Janssens reports grants from AstraZeneca and Chiesi, consultation fees from AstraZeneca, Chiesi, GSK and Sanofi, payment or honoraria for lectures, presentations, manuscript writing or educational events from AstraZeneca, Chiesi and GSK, support for attending meetings from AstraZeneca and Chiesi, and the following financial (or non-financial) interests: co-founder and chairholder of ARTIQ, a spin-off company of KULeuven. M. Staes, K. Goetschalckx and T. Troosters have nothing to disclose., (Copyright ©The authors 2024.)

Background: There are few studies on the safety of sub-maximal exercise testing of aerobic exercise in apparently healthy Chinese populations. The purpose of this study was to explore the frequency of exercise electrocardiography (ECG) abnormalities and the corresponding exercise intensities, as well as the associated influencing factors, during a symptom-limited stepwise incremental cardiopulmonary exercise test (CPET) in an apparently healthy Chinese population., Methods: A cross-sectional study was done in four communities, one urban and one rural in the North (Beijing) and in the South (Hezhou, Guangxi) of China from 1 January 2017 to 31 December 2018, respectively. Total of 1642 participants was recruited, 918 were eligible and completed demographic indicators, routine blood indicators, physical activity status, symptom-limited CPET and exercise ECG were included in the analysis., Results: Of the exercise ECG outcomes, 10 (1.1%) were positive and occurred at exercise intensities ≥ 62.50% heart rate reserve (HRR); 44 (4.8%) were equivocal and 864 (94.1%) were normal. Individuals with Cardiovascular Disease Risk Factor (CVDRF) = 3-4 were 2.6 times more likely to have a equivocal and abnormal exercise ECG than those with CVDRF = 0-2. Exercise ECGs of individuals with CVDRF = 5-7 were 5.4 times more likely to be positive and abnormal than exercise ECGs of individuals with CVDRF = 0-2., Conclusions: The exercise intensity of 62.5% HRR can be used as a safe upper limit for safe participation in exercise in apparently healthy Chinese population; the greater the number of CVDRFs, the greater the likelihood of cardiovascular risk during exercise., (© 2024. The Author(s).)

Background: This study was designed to evaluate the effect of using maximal cadence criteria cut points established during overground and treadmill walking, on intensity outputs measured during community ambulation. The second aim was to establish the relationship between cardiovascular fitness (predicted VO 2 max capacity) and community ambulation intensity performance, in typically developing individuals., Research Question: What is the effect on intensity measures when using cadence cut point criteria derived from overground and treadmill walking and does predicted VO 2 max correlate with exercise related community activity in a typically developing population?, Methods: A group of 37 typically developing participants between 8 and 27 years of age, underwent a graded submaximal VO 2 testing protocol followed by a typical week of community ambulation, recorded with a step activity monitor. Maximum cadence criteria established during overground and treadmill walking were applied and the data were compared. The weekly step activity variables included: total steps, total ambulatory time, intensity, duration, and volume. Predicted VO 2 Max was calculated, and correlations calculated to step activity outputs., Results: Results showed significant differences (p<0.001) between cadence cut point criteria across all intensity measures except in the amount of time spent in the 30-60 % intensity category (p=0.182). Predicted VO 2 max did not significantly correlate with step activity outputs related to exercise (moderate+ intensity and long duration ambulatory bouts; p>0.277)., Significance: This study illustrates the importance of close consideration in applying recommended cut off criteria when assessing intensity outputs from step activity data. Cadence from both overground and treadmill walking were collected in a controlled lab setting, but the influence of the treadmill mechanical and forced cadence criteria must be considered when selecting intensity cut points., Competing Interests: Declaration of Competing Interest none, (Published by Elsevier B.V.)

Background: Aerobic fitness is a predictor of cardiovascular health which correlates with health-related quality of life in the general population. The aim is to evaluate the aerobic capacity by cardiopulmonary exercise test (CPET) in children with sickle cell disease in comparison with healthy matched controls., Methods: Controlled cross-sectional study., Results: A total of 72 children (24 with sickle cell disease and 48 healthy controls), aged 6-17 years old were enrolled. Children with sickle cell disease had a poor aerobic capacity, with median VO 2max Z-score values significantly lower than matched controls (-3.55[-4.68; -2.02] vs. 0.25[-0.22; 0.66], P < 0.01, respectively), and a high proportion of 92% children affected by an impaired aerobic capacity (VO 2max Z-score < -1.64). The VO 2max decrease was associated with the level of anemia, the existence of a homozygote HbS/S mutation, restrictive lung disease and health-related quality of life., Conclusion: Aerobic capacity is poor in children with sickle cell disease. VO 2max decrease is associated with the level of anemia, the existence of a homozygote HbS/S mutation, lung function, and health-related quality of life. These results represent a signal in favor of early initiation of cardiac rehabilitation in patients with sickle cell disease., Clinical Trials: NCT05995743., Impact: Aerobic fitness is a predictor of cardiovascular health which correlates with health-related quality of life in the general population. Aerobic capacity (VO 2max ) is poor in children with sickle cell disease, despite the absence of any pattern of heart failure. VO 2max decrease was associated with the level of anemia, the existence of a homozygote HbS/S mutation, restrictive lung disease, and health-related quality of life. These results are in favor of early initiation of cardiac rehabilitation in children with sickle cell disease., (© 2024. The Author(s), under exclusive licence to the International Pediatric Research Foundation, Inc.)

Background: Conventional measures of heart rate variability (HRV) have shown only modest associations with sudden cardiac death (SCD). Detrended fluctuation analysis (DFA), with novel methodological developments to evaluate the short-term scaling exponent, is a potentially superior method compared to conventional HRV tools., Objectives: In this study, the authors studied the analysis of the association between DFA and SCD., Methods: The investigators studied the predictive value of ultra-short-term heart rate fluctuations (1-minute electrocardiogram samples) with DFA at rest and during different stages of physical exertion for incident SCD among 2,794 participants undergoing clinical exercise testing in the prospective FINCAVAS (Finnish Cardiovascular Study). The novel key DFA measure, the short-scale scaling exponent computed with second-order detrending (DFA2 α 1 ), was the main exposure variable. SCDs were defined by American Heart Association/European Society of Cardiology criteria using death certificates with written accounts of the events., Results: During a median follow-up of 8.3 years (Q1-Q3: 6.4-10.5), 83 SCDs occurred. DFA2 α 1 measured at rest (but not in exercise) associated highly significantly with the risk of SCD, with 1-SD lower values associating with a 2.4-fold (Q1-Q3: 2.0-3.0) risk (P < 0.001). The results persisted when adjusting for other major risk factors for SCD, including age, cardiovascular morbidities, cardiorespiratory fitness, heart rate reduction, and left ventricular ejection fraction. Associations between conventional HRV parameters (measured at any stage of exercise or at rest) and SCD were substantially weaker and statistically nonsignificant after adjusting for other risk factors., Conclusions: Ultra-short-term DFA2 α 1 , when measured at rest, is a powerful and independent predictor of SCD. The association between DFA2 α 1 and SCD is modified by physical exertion., Competing Interests: Funding Support and Author Disclosures FINCAVAS has been financially supported by the Competitive Research Funding of Tampere University Hospital (grants 9M048 and 9N035); the Finnish Cultural Foundation; the Finnish Foundation for Cardiovascular Research (to T.L); the Emil Aaltonen Foundation; the Tampere Tuberculosis Foundation, EU Horizon 2020 (grants 755320 for TAXINOMISIS and 848146 for To Aition); and the Academy of Finland (grant 322098). Additional funding has been also granted by Business Finland, R2B Funding 2022-23 (to E.R). The authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Purpose : In this study we evaluated the reliability of blood lactate levels (BLa), energy expenditure and substrate utilization during prolonged exercise at the intensity that elicits maximal fat oxidation (FATmax). Furthermore, we investigated the accuracy of a single graded exercise test (GXT) for predicting energy metabolism at FATmax. Methods : Seventeen young men with obesity (26 ± 6 years; 36.4 ± 7.2 %body fat) performed a GXT on a treadmill in a fasted state (10-12 h) for the assessment of FATmax and cardiorespiratory fitness. Afterward, each subject performed two additional prolonged FATmax trials (102 ± 11 beats·min -1 ; 60-min) separated by 7 days. Indirect calorimetry was used for the assessment of energy expenditure and substrate utilization kinetics whereas capillary blood samples were taken for the measurement of BLa. Results : The BLa (limits of agreement (LoA): -1.2 to 0.8 mmol∙L -1 ; p = 1.0), fat utilization (LoA: -8.0 to 13.4 g∙h -1 ; p = 0.06), and carbohydrate utilization (LoA: -27.6 to 22.4 g∙h -1 ; p = 0.41) showed a good agreement whereas a modest systematic bias was found for energy expenditure (LoA: -16811 to 33355 kJ∙h -1 ; p < 0.05). All the aforementioned parameters showed a moderate to good reliability (Intraclass correlation coefficient: 0.67-0.92). The GXT overestimated fat (~46%) and carbohydrate (~26%) utilization as well as energy expenditure (36%) during steady-state exercise at FATmax. Conversely the GXT underestimated BLa (~28%). Conclusion : a single GXT cannot be used for an accurate prediction of energy metabolism during prolonged exercise in men with obesity. Thus, an additional steady-state FATmax trial (40-60 min) should be performed for a tailored and precise exercise prescription.

Background: Alterations caused by face masks on physiological responses vary among different population groups. This study aimed to investigate whether physically active and sedentary individuals respond differently to face mask use during exercise., Methods: Sixteen healthy college students were divided into two groups: Physically active group (N.=10; 26.50±2.80 years) and Sedentary group (N.=6; 26.33±2.81 years). They performed three maximal cardiopulmonary exercise test (CPET)s following the Bruce protocol: one without a face mask (NON), one with a surgical mask (SUR) and one with a cloth mask (CLO). Cardiorespiratory parameters and heart rate were monitored continuously during the test. Blood pressure, oxygen saturation and lactate level were measured immediately before and after exertion., Results: Significant differences were found between the Physically active and the Sedentary group in peak VO2 (VO2peak) in NON (P=0.030). However, this difference disappeared when the face masks were used. Furthermore, VO2/kg (P=0.002) and METs (P=0.002) decreased significantly at the respiratory compensation point (RCP) only in the Physically active group with face masks. No significant differences were found between the two groups for exercise time, lactate level and dyspnea (P>0.05)., Conclusions: The decrease in exercise tolerance and cardiorespiratory responses, particularly VO2peak, due to face mask use was greater in physically active individuals compared to sedentary individuals. Population group characteristics should be considered when adapting face masks to daily life.

Background: While numerous studies have explored age and playing position effects on fitness levels in male adolescent soccer players, research on female players in this context is lacking. The purpose of this study was to examine the effects of age and playing position on field-based physical fitness measures in adolescent female soccer players, with consideration for maturity., Methods: This cross-sectional study involved 284 females aged 12.0-15.9 years. Participants performed the 20-m multi-stage fitness test (20MSFT) to assess estimated maximum oxygen uptake (VO2max), 10-m and 20-m sprints, 505 Test to evaluate change of direction speed (CODS), the medicine ball chest throw (MBCT) and countermovement vertical jump (CMVJ) to assess muscle power. For data analysis, participants were separated into age groups (12, 13, 14, and 15 years), and playing position (forward, midfielder, defender, and goalkeeper). Age at peak height velocity was considered a covariate to account for maturity status., Results: Players aged 14 years demonstrated faster CODS compared to 15 years old (P=0.014), while superior MBCT performance was noted at both ages compared to younger ages (P<0.001). Goalkeepers exhibited lower VO2max than midfielders and defenders (P<0.05). Defenders and goalkeepers exhibited greater hip circumference and body mass compared to midfielders (P≤0.01), along with a larger waist circumference for defenders compared to midfielders (P=0.003). Age and position interactions were absent. When analyses were run without controlling for maturity, all results were the same except for CODS where no age effect was found., Conclusions: This study suggests that upper body power, and flexibility may be impacted by age and playing position in adolescent female soccer players, regardless of maturity status. The CODS appears to be influenced by age only when controlling for maturity.

Introduction: Field tests are commonly used as complements of cardiopulmonary exercise test (CPET) to evaluate the functional exercise capacity. The aims of this study were to validate the one-minute sit-to-stand test (STST) in congenital heart disease (CHD) children and to evaluate the possibility of predicting the peakVO 2 using the STST in this paediatric population., Methods: Children (8- to 18-year-old) followed for a CHD and performing CPET were recruited prospectively. Concomitantly, they performed STST. The heart rate (HR), oxygen saturation (SpO 2 ), muscular fatigue and dyspnoea were recorded before (t0), immediately after (t1) and 1min after the end of the STST (t2)., Results: We observed a poor but significant correlation between the STST and the peakVO 2 (r=0.306; p=0.013). A significant difference between girls and boys were observed for peakVO 2 (p<0.001), HR t0 (p=0.030), HR t1 (p=0.002) and HR t2 (p<0.001). The proposed model of prediction, including the number of STST, weight, height and age explains 37% of the predicted peakVO 2 variance., Conclusion: The STST can provide relevant data on physical capacity in children with CHD. When CPET cannot be performed, we therefore propose an alternative equation using the STST as a surrogate of peakVO 2 in CHD children., (Copyright © 2024 SEPAR. Published by Elsevier España, S.L.U. All rights reserved.)

Detailed heart rate (HR) response patterns during exercise in patients with heart failure (HF) and sinus rhythm remain uncertain. We screened consecutive patients with HF who underwent cardiopulmonary exercise tests at a large academic center from November 2013 to July 2023. HR response during exercise was statistically classified using logistic differential equation models. A total of 99 patients were included. Of them, 75 patients were assigned to "sigmoidal pattern" and the other 24 to "exponential pattern." Patients with the sigmoidal pattern were older and exhibited higher plasma B-type natriuretic peptide levels. Increases in HR and oxygen consumption (V̇o 2 )/kg up to the anaerobic threshold level were not different between both patterns. However, beyond the threshold, the sigmoidal pattern group showed no further increase in HR and significantly lower V̇o 2 /kg than their counterparts (interactions for P < 0.001). HR response during exercise in patients with heart failure and sinus rhythm was categorized into two unique groups: sigmoidal and exponential patterns. More detailed clarification of the sigmoidal pattern, potentially indicating sinus node dysfunction, should offer new clinical insights for chronotropic incompetence. NEW & NOTEWORTHY Heart rate response patterns can be classified into two groups among patients with chronic heart failure reaching maximal exertion: sigmoidal and exponential.

Objectives: To compare reach distances between the YBT-LQ and SEBT using the correct protocols as outlined by the developers. This will provide an accurate insight on the actual magnitude differences in reach distance between the movement screen tests and will safeguard practitioners on the subsequent use of these outcomes to inform clinical decision making., Design: Observational., Setting: Laboratory., Participants: Participants included sixteen healthy female subjects from the university and amateur sports teams., Main Outcome: Reach distances in the anterior direction (ANT), posterior medial (PM) and posterior lateral (PL) between participants on the YBT-LQ and SEBT., Results: The principal findings highlighted that a statistically significantly greater reach distance on the left and right side for the YBT-LQ compared to the SEBT in the ANT, PM, and PL directions (p < 0.0005)., Conclusion: The results of this study suggest that the YBT-LQ and SEBT are not comparable tests due to the differences in reach distance and methodological differences. Therefore, previous, and future research using the YBT-LQ and SEBT cannot be used interchangeably. Not following developed guidelines questions the applicability of the findings of reach distance scores to infer on performance and assessment of injury risk., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: Diabetes is a risk factor for the development of vascular disease, chronic kidney disease, retinopathy, and neuropathy. Diabetes is a co-morbid condition commonly present in patients with respiratory disorders but the extent to which it influences ventilatory capacity, gas exchange, and functional capacity is not well known. Research question Does the presence of diabetes contribute to impairment in spirometry, gas transfer, and exercise capacity?, Methods: Retrospective analysis of all subjects who performed incremental cardio-pulmonary exercise testing (CPET) between 1988 and 2012 at McMaster University Medical Centre. The impact of diabetes on physiological outcomes and maximum power output (MPO) was assessed using stepwise multiple additive linear regression models including age, height, weight, sex, muscle strength, and previous myocardial infarct as co-variates, and was also stratified based on BMI categories., Results: 40,776 subjects were included in the analysis; 1938 (5%, 66% male) had diabetes. Diabetics were older (59 vs. 53 years), heavier (88.3 vs.78.0 kg), and had a higher BMI (31 vs. 27 kg/m 2 ). The presence of diabetes was independently associated with a reduction in FEV1 (- 130 ml), FVC (- 220 ml), DLCO (- 1.52 ml/min/mmHg), and VA (- 340ml) but not KCO. Patients with diabetes achieved a lower % predicted MPO[diabetic subjects 70% predicted (670 kpm/min ± 95% CI 284) vs. 80% in non-diabetics (786 kpm/min ± 342), p < 0.001]. With the exception of KCO, these differences persisted across BMI categories and after adjusting for MI., Conclusion: The presence of diabetes is independently associated with weaker muscles, lower ventilatory and gas transfer capacity and translates to a lower exercise capacity. These differences are independent of age, height, weight, sex, and previous MI., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Objectives: Hemodynamic gain index (HGI), a novel hemodynamic index obtained from cardiopulmonary exercise testing (CPX), is associated with adverse cardiovascular outcomes. However, its specific relationship with ventricular arrhythmias (VAs) is unknown. We aimed to assess the association of HGI with risk of VAs in a prospective study. Design: Hemodynamic gain index was estimated using heart rate and systolic blood pressure (SBP) responses ascertained in 1945 men aged 42-61 years during CPX from rest to maximum exercise, using the formula: [(Heart rate max x SBP max ) - (Heart rate rest x SBP rest )]/(Heart rate rest x SBP rest ). Cardiorespiratory fitness (CRF) was measured using respiratory gas exchange analysis. Hazard ratios (HRs) (95% confidence intervals, CIs) were estimated for VAs. Results: Over a median follow-up duration of 28.2 years, 75 cases of VA were recorded. In analysis adjusted for established risk factors, a unit (bpm/mmHg) higher HGI was associated with a decreased risk of VA (HR 0.72, 95% CI: 0.55-0.95). The results remained consistent on adjustment for lifestyle factors and comorbidities (HR 0.72, 95% CI: 0.55-0.93). Comparing the top versus bottom tertiles of HGI, the corresponding adjusted HRs (95% CIs) were 0.51 (0.27-0.96) and 0.52 (0.28-0.94), respectively. The associations were attenuated on addition of CRF to the model. HGI improved risk discrimination beyond established risk factors but not CRF. Conclusions: Higher HGI is associated with a reduced risk of VAs in middle-aged and older Caucasian men, but dependent on CRF levels. Furthermore, HGI improves the prediction of the long-term risk for VAs beyond established risk factors but not CRF.

In pre-pubertal children the factors affecting maximal oxygen uptake have yet to be fully understood. Therefore, the purpose of this analysis is to present cardiorespiratory fitness in prepubertal boys and girls and to determine if there are any differences based on sex, exercise testing modality or if maximal or peak oxygen consumption metrics are used. PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were followed. For statistical analysis, multilevel models grounded in Bayesian principles were used. Selected studies obtained: maximal effort during the test, peak or maximal oxygen consumption (V̇O 2 ) values, boys and girls (sex specific groups only) age under 11, cycle ergometry or treadmill, pre-intervention or no intervention data. In boys using cycle ergometry, 118 studies were included in the analysis, in boys using treadmill 115, in girls using cycle ergometry 83 and in girls using treadmill testing 95 study entries were included. As children get older, their cardiorespiratory fitness increases (P ≈ 100%). Studies with participants having smaller body mass have higher V̇O 2 relative to body mass values (P ≈ 100%). Boys have higher V̇O 2 values than girls (P ≈ 100%). Studies using treadmill reported higher values than those using cycle ergometer (P ≈ 100%). Regarding the influence of measurement method (max vs. peak) on V̇O 2 values we did not find significant differences. In conclusion, we present reference values for cardiorespiratory fitness in prepubertal boys and girls using cycle ergometry or treadmill. Prepubertal boys have higher cardiorespiratory fitness than girls and using treadmill testing might be a preferred method to cycle ergometry, especially in older children. Maximal or peak oxygen consumption metrics might be used interchangeably in prepubertal children., (© 2024. The Author(s).)

Objectives: In this study, we aimed to assess the maximal oxygen uptake (VO 2max ) of young, healthy, non-athletic Saudi men using maximum graded exercise with instant breath-by-breath analysis and to compare this value to the predicted VO 2max by international formulae. Methods: In this cross-sectional study, 88 young non-athletic normal-weight Saudi subjects were recruited from Eastern Province of Saudi Arabia with mean age (21.3 ± 1.5 years), weight: (64.7 ± 7.5 kg), height: (172.3 ± 6.1 cm) and body mass index: (21.8 ± 2.1). All subjects were interviewed and examined for eligibility, after which they performed maximum graded exercise testing on a treadmill to obtain VO 2max . The predicted VO 2max was also generated using the following formulae (Edvardsen, Fairbarns, FRIENDS, Hansen, and Jones). Results: The mean measured VO 2max was 41.9 ± 7.2 ml/kg/min. While the predicted VO 2max using the formulae were: Edvardsen = 66.8 ± 7.9, Fairbarns = 64.1 ± 4.7, FRIENDS = 53.5 ± 2.2, Hansen = 42.8 ± 0.54, and Jones = 50.9 ± 5.1 ml/kg/min. There was a significant difference between all the predicted VO 2max and the measured one using the paired t-test (P < 0.001), except for the Hansen's predicted value (P = 0.212). The effect size index (Cohen's d) for the comparison of Hansen's VO 2max and measured VO 2max was trivial and equal to 0.13. The Bland-Altman test showed good agreement between the measured and Hansen's predicted VO 2max . Conclusion: This study demonstrated the mean VO 2max value of young, healthy, and non-athletic Saudi men. This value was lower than Western values, which might be due to low physical activity or racial differences. Most international formulae overestimate the VO 2max in this population, except for the Hansen equation. Therefore, Hansen's predicted VO 2max might be the best available reference value for the diagnosis and prognosis of young Saudi individuals undergoing maximum exercise testing., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Competing Interests: Conflict of interest: None declared.