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Abstract: Bordelon, NM, Agee, TW, Wasserberger, KW, Downs-Talmage, JL, Everhart, KM, and Oliver, GD. Field-testing measures related to youth baseball hitting performance. J Strength Cond Res 39(2): 210-216, 2025-The purpose of the study was to determine the relationship between field tests and youth hitting performance (batted-ball velocity). Forty-nine youth baseball athletes (age: 11.1 ± 1.6 years; height: 151.7 ± 13.2 cm; body mass: 47.1 ± 15.1 kg) were rotated through the following field tests: passive bilateral hip and shoulder internal rotation (IR) and external rotation (ER) range of motion (ROM), bilateral hip and shoulder ER and IR isometric (ISO) strength, bilateral grip strength, trunk rotation ROM, standing broad jump (SBJ), triple broad jump, single leg lateral rotational jumps, and 3 maximal effort hits off a stationary tee. Regression analyses were performed to determine the associations between grip strength, hip strength, jump tests, and ROM with batted ball velocity. For the grip strength, hip strength, and jump tests regression models, body mass (kg) and height (cm) were entered first to estimate the proportion of variance accounted for by anthropometrics. A Bonferroni correction was applied a priori to α = 0.013. The jump-testing model, including only SBJ distance, was the best predictor of batted ball velocity above and beyond the predictive effects of anthropometric measures. Although less than the jump-testing model, the results determined that the hip strength model, including only nondominant hip ER ISO strength, was the second-best predictor of batted ball velocity. Practitioners can use these tests to monitor training progression in youth baseball athletes and identify deficits in physical ability that can be improved., (Copyright © 2025 National Strength and Conditioning Association.)

AbstractBecause symptoms of cardiopulmonary disease often occur with exertion, cardiopulmonary exercise testing (CPET) has a unique role in the assessment of patient symptoms, disease severity, prognosis, and response to therapy. In addition to the evaluation of cardiovascular and pulmonary physiology, CPET provides an assessment of the interaction of the cardiovascular and pulmonary systems with the musculoskeletal, nervous, and hematological systems. In this article, we review key CPET variables, protocols, and clinical indications.

This study aims to determine the validity of the linear critical power (CP) and Peronnet models to estimate the power output associated with the second ventilatory threshold (VT2) and the maximal aerobic power (MAP) using two-time trials. Nineteen recreational runners (10 males and 9 females and maximum oxygen uptake: 53.0 ± 4.7 mL/kg/min) performed a graded exercise test (GXT) to determine the VT2 and MAP. On a second test, athletes performed two-time trials of 9 and 3 min interspaced by 30 min. The CP was determined from the linear CP model and compared with the power output associated with the VT2. The MAP was determined from the linear Peronnet model, established at 7 min, and compared with the MAP determined in the GXT. The CP model was valid for determining the VT2, regardless of sex (p = 0.130; 9/3 vs. GXT: 3.5 [-1.1 to 8.2] W). The MAP was overestimated (p = 0.015) specifically in males (9/3 vs. GXT: 9.2 [3.3 to 15.1] W) rather than in females (p = 9/3 vs. GXT: 1.7 [-4.4 to 8.0] W). Therefore, MAP estimates were determined introducing the CP and W' parameters to a stepwise multiple linear regression analysis. For females, the CP was the unique significant predictor of MAP (p < 0.001) explaining 96.7% of the variance. In males, both CP and W' were significant predictors of MAP (p < 0.001) explaining 97.7% of the variance. Practitioners can validly estimate the VT2 and MAP through a practical testing protocol in both male and female recreational runners., (© 2025 The Author(s). European Journal of Sport Science published by Wiley‐VCH GmbH on behalf of European College of Sport Science.)

We assessed the validity, reliability, and transferability of gas exchange and ventilatory variables from two commonly used metabolic measurement systems (COSMED Quark and VO2Master Pro). Two identical devices from each system were independently connected to a metabolic simulator (VacuMed), and 2 min of steady-state data was recorded at simulated oxygen uptake (V̇O 2 ) of 1, 2, 3, and 4 L∙min -1 achieved through minute ventilation (V̇ E ) of 30, 60, 105, and 150 L∙min -1 . Each metabolic analyzer recorded data three times for each "intensity" in a randomized order, and assessments were completed on two separate days. Douglas bag-based measurements were also made once at each simulated "intensity". Measured steady-state data (average of final 1.5 min) for both V̇O 2 (STPD) and V̇ E (ATPS) were compared with simulated values to assess validity, repeated values between and within days assessed reliability, and between-device comparisons provided transferability. Including both COSMED devices at all intensities, the mean percent error for V̇O 2 was 3.5% (range: -2.5%-8.1%) and, for V̇ E , was 2.0% (-0.5%-7.6%). For the VO2Master, these values averaged 0.6% (-9.3%-4.8%) and 1.1% (-6.3%-4.0%) for V̇O 2 and V̇ E , respectively. Mean percent error for Douglas Bag was 1.5%, -3.7%, -3.1%, and -2.0% for 1, 2, 3, and 4 L∙min -1 , respectively. Between-day differences (reliability) for V̇O 2 of both COSMED devices ranged from -4.1% to 2.2% (mean 0.1%) and, for both VO2Masters, between -1.6% and 11.1% (mean 1.2%). Between-device differences (transferability) ranged from -3.5% to 0.5% (mean 1.3%) for COSMED and from -11.0% to 3.6% (mean 0.0%) for VO2Master. Mean values and ranges for V̇ E were similar. When used appropriately in laboratory settings, the COSMED Quark and VO2Master Pro systems provide gas exchange and ventilatory data within an acceptable range for metabolic testing equipment that are both reliable and transferable between optimally performing devices., (© 2025 The Author(s). Scandinavian Journal of Medicine & Science In Sports published by John Wiley & Sons Ltd.)

Purpose: This study aimed to explore the association and prediction of hip abduction-adduction and knee flexion-extension isokinetic absolute and relative strength and power at 60°/s and 180°/s from functional tests performance (i.e., Up-and-Go Test [seconds], 30-Second Chair Stand Test [repetitions and relative and allometric power], 30-Second Arm Curl Test [repetitions], and 6-Minute Walk Test [meters]) in older adults., Methods: Five hundred and fifty participants (404 women; age: 69.12 ± 5.29 years) enrolled in this cross-sectional study. Participants attended the laboratory once. Isokinetic concentric-concentric strength was assessed before physical fitness tests. Agility and dynamic tests were completed before strength and aerobic resistance tests within the physical fitness tests., Results: Significant trivial-to-moderate correlations (positive and negative) were found between all the tests and the isokinetic strength and power of the knee and the hip. The performance in the UGT and 6MWT showed the best direct correlations with isokinetic strength and power (|r| = 0.09-0.48), and the 30CS and 30 AC showed inconsistent positive and negative correlations (r = -0.46-0.44). Significant regression equations including the functional tests, age, and sex were found, with higher values for knee isokinetic strength and power (R 2  = 0.19-0.44) compared to hip (R 2  = 0.09-0.35) and no clear pattern regarding better or worse predictability at higher angular velocities., Conclusions: Isokinetic knee and hip strength and power are associated with functional fitness in older adults. The functional fitness tests, along with age and sex are predictive variables of older adults' lower-limb isokinetic strength, although explaining at most 44 % of the variance., Competing Interests: Declaration of competing interest The authors declare that they have no competing interests., (Copyright © 2025 The Authors. Published by Elsevier Inc. All rights reserved.)

Purpose: Physical activity and a healthy lifestyle play an essential role in optimizing long-term health in patients with Fontan physiology. Wrist-worn activity trackers may be useful in medically directed exercise programs for patients with Fontan physiology. The objective of this study was to measure the validity of Garmin and Fitbit activity tracker heart rate detection in patients with Fontan circulation when compared with electrocardiogram during cardiopulmonary exercise testing (CPET)., Methods: Forty-seven Fontan patients undergoing CPET for clinical indications were included and wore activity trackers during CPET. Heart rate via the activity tracker was collected at baseline, maximal exercise, and recovery. Patient heart rates, peak V̇O 2 , and peak respiratory exchange ratio were collected using standard CPET protocols and equipment. Heart rate at each time point was compared between the activity trackers and CPET electrocardiogram., Results: Median age of participants was 17.1 yr, 15.1 yr since Fontan completion. Mean percentage of predicted peak V̇O 2 was 56.8%, with a z -score of -3.2, and 61.7% of participants completing a maximal CPET. Baseline mean oxygen saturation was 92.9% and 90.0% at maximal exercise. Activity trackers demonstrated mean absolute percentage error <10% at most time points, comparable with other studies. Demographics, Fontan-associated comorbidities, and echocardiogram findings did not impact the accuracy., Conclusions: Consumer-oriented wrist-worn activity trackers show promising accuracy for heart rate monitoring in medically directed exercise programs for adolescents and young adults with Fontan physiology. Further validation across different exercise modalities is needed., (Copyright © 2024 by the American College of Sports Medicine.)

Background: Central Augmentation Index (AIx) is a surrogate marker of large artery stiffness that may provide valuable insight to cardiovascular health. The aim of this study was to evaluate the relationship between AIx and components of physical fitness., Methods: One hundred eighty-five healthy men and women (aged 20-79 years) underwent non-invasive assessment of arterial wave reflection to determine AIx, which was corrected to a heart rate of 75 beats per minute (AI×75). Body composition was evaluated using dual energy X-ray absorptiometry (DXA) and aerobic capacity (VO2max) was derived from expired gas analysis during a symptom limited exercise test on a treadmill., Results: A multiple linear regression revealed age and VO2max as significant predictors of AI×75 [AI×75=32.055 + (0.252×age) - (0.722×VO2max)]. Upon removal of VO2max from regression analysis, resting heart rate (RHR) and % body fat (BF%) were revealed to be significant predictors of AI×75: AI×75=-61.316 + (0.481×age) + (0.565×BF%) + (0.56×RHR)., Conclusions: Our findings demonstrate that central Augmentation Index can be reliably predicted in healthy adults who undergo a maximal exercise or body composition assessment. These prediction equations may be applied in non-medical settings to assist in creating comprehensive health and fitness profiles for healthy clientele.

Abstract: King, BW, Snow, TK, and Millard-Stafford, M. Peak lower-extremity power unadjusted for body mass predicts fastball velocity in collegiate baseball pitchers. J Strength Cond Res 39(2): 217-226, 2025-The relationship between lower-extremity power production and fastball velocity in collegiate pitchers remains unclear. This study aimed to evaluate the relationship between lower-extremity power and throwing velocity in 33 National Collegiate Athletic Association Division I baseball pitchers. Lower-extremity power was quantified using countermovement jump (CMJ) testing on force plates and the Wingate anaerobic cycling test. In-game fastball velocities were collected using TrackMan technology. Pearson correlations and linear regressions were used to evaluate the association between lower-body power and fastball velocity. The strongest predictor of peak fastball velocity was body mass ( r = 0.58, p = 0.0004), followed by lean mass ( r = 0.52, p = 0.002). Peak power (W) produced on the Wingate and CMJ tests were each statistically significant predictors of peak velocity ( r = 0.44, p = 0.011; r = 0.43, p = 0.014, respectively), but CMJ power relative to body mass ( r = 0.19), jump height ( r = 0.07), and Sparta Scores ( r = -0.06) were not ( p > 0.05). Linear regression indicated Wingate and CMJ absolute peak power tests each independently explained 19% of the variance in fastball velocity but added little to the model when combined with body mass (∼34 vs. 32% of total variance). Because total body mass and lower-body power are important predictors of pitching velocity, absolute power output is a more relevant predictor of baseball pitching velocity than lower-body power variables influenced by body mass (e.g., jump height and Sparta Score)., (Copyright © 2024 National Strength and Conditioning Association.)

Abstract: Talpey, SW, Drake, M, Haintz, L, Belanger, A, O'Grady, MW, Young, WB, Mundy, PD, James L, Gabbett, TJ, Gardner, EC. The reliability and validity of the rebound countermovement jump in National Collegiate Athletic Association Division I American football players. J Strength Cond Res 39(2): 200-209, 2025-The purpose of this study was to investigate the reliability and validity of the rebound countermovement jump (R-CMJ), as an alternate test of leg muscle function to the CMJ and drop jumps (DJs). Because the first phase of the R-CMJ mimics that of the CMJ, it is hypothesized that variables obtained in phase I of the R-CMJ will be like those of a CMJ. Similarly, because the second phase of a R-CMJ mimics a DJ, it is believed that the variables obtained from phase II will be like those from a DJ. Collegiate male American football players ( N = 46) aged 18-24 years completed CMJs and R-CMJs on a portable force plate. Tests were completed on 3 separate days to determine the repeatability of select variables and to establish their validity. In addition, a subgroup ( N = 20) of players from the cohort completed DJs from both 30 cm (DJ30) and 45 cm (DJ45) to determine the concurrent validity of the variables obtained from the second phase of the R-CMJ. Most variables obtained from the CMJ and R-CMJ phase I were found to be reliable, except for time-to-take-off. The variables from the DJ30, DJ45, and R-CMJ phase II displayed moderate to good reliability; however, all coefficient of variations were >10%. Jump height achieved in the CMJ was significantly greater than that achieved in phase I of the R-CMJ. The reactive strength index was significantly different in the R-CMJ compared with the DJ from both 30 and 45 cm heights. Although the R-CMJ may be inviting for coaches to use owing to its ease and time efficiency, the results of this study highlight that it may not provide a valid representation of an athlete's reactive strength., (Copyright © 2024 National Strength and Conditioning Association.)

Abstract: Bishop, C. Using ratio data in strength and conditioning: component parts hold the key. J Strength Cond Res 39(2): e176-e179, 2025-In strength and conditioning, ratio data are made up of more than 1 component part and are now commonplace in both research and practice, with an abundance of metrics from strength and jump testing being used as part of the ongoing monitoring process. Given these data have been used for many years, their inherent issues may not be obvious to all practitioners. However, ratio data often exhibit greater measurement error than their individual component parts. In addition, monitoring alterations in ratio data also presents challenges, given there is more than 1 way that the resultant test score can change. This brief review provides some practical examples to illustrate these challenges but also some viable solutions to guide practitioners on how the concurrent monitoring of ratios and their component parts can help guide decision-making in day-to-day practice., (Copyright © 2024 National Strength and Conditioning Association.)

Introduction: The one-minute sit to stand test (1min-STST) is a field test used to assess functional capacity. It is easily implementable and of significant clinical utility; however, no reference values are currently available for the Chilean population. The objective of this study was to establish reference values for the 1min-STST in a healthy Chilean population., Methods: A multicenter cross-sectional study involving data collection from six locations in Chile was conducted. Healthy adults between 18 and 80 years of age were recruited. The anthropometric variables, levels of physical activity, smoking status, Borg scale ratings, and number of repetitions during the 1min-STST were recorded. Reference values were determined according to sex and age range., Results: Four hundred ninety-nine healthy subjects (57.5% women, n = 287; median height, 1.63 (0.14) m; weight, 72.8 (20) kg; average BMI, 27.3 ± 4.1 kg/m2) were included in the study. The median (and the lower limit of normality (LLN) values) for the 1min-STST in men ranged from 18-29 years, with 38 (LLN 27) repetitions and 23 (LLN 15) repetitions for 70-80 years. For women aged 18-29 years, 38 (LLN 28) repetitions were performed, and for women aged 70-80 years, 24 (LLN 17) repetitions were performed., Conclusions: This study established reference values for the healthy adult Chilean population., Competing Interests: None of the authors declare any conflict of interest for this research, (Copyright: © 2025 Otto-Yáñez 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.)

Police tactical group (PTG) officers respond to the most demanding and high-risk police situations. As such, PTG personnel require exceptional physical fitness, and selection for employment often evaluates fitness both directly and indirectly. While heart rate (HR) is often used to measure physical effort, heart rate variability (HRV) may be a valuable tool for measuring stress holistically. The primary aim of this research was to investigate whether HRV was more sensitive than HR at monitoring workload during key PTG selection activities. As aerobic fitness is associated with workload during these tasks, a secondary aim was to investigate relationships between HRV, HR and aerobic fitness during the same tasks. The relationships between HRV (percentage of adjacent R-R intervals varying by 50% or more; pRR50%) and HR, as measured by ambulatory electrocardiograms obtained during a specialist police selection course, as well as aerobic fitness, as determined via total shuttles completed on the 20-meter multistage fitness test (MSFT; 'beep test'), were investigated. This study included a cohort of six male PTG candidates (n = 6) undergoing selection. As illustrated by a time-series plot, HR values were generally unremarkable, but HRV values were potentially depressed, and tentatively indicated overstress when count data from consecutive short-term analyses were derived. The MSFT was significantly, positively, correlated with pRR50% (ρ (6) = 0.812, p = 0.050, Fisher's z = 1.132). The MSFT and nonlinear HRV, frequency domain HRV, and HR were not significantly correlated. When assessed by linear regression, neither HRV nor HR were predicted by MSFT score. These findings indicate that HR alone is likely not sufficiently sensitive to provide detail on the stress response of candidates undertaking essential tactical tasks that combine physical stressors with cognitive load in adverse conditions. HRV analysis may provide additional insights regarding candidate suitability, particularly during dynamic and multifaceted assessments, though the causal direction of the relationship between HRV and aerobic fitness remains unclear., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2025 Tomes 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.)

Aims: Exercise testing remains underused in patients with aortic stenosis (AS), partly due to concerns about an exercise-induced drop in systolic blood pressure (SBP). We aimed to study the SBP response to exercise in patients with severe symptomatic AS prior to surgery and 1 year postoperatively., Methods: Patients scheduled for aortic valve replacement due to severe symptomatic AS were enrolled at a single centre in a prospective observational cohort study. Maximal cardiopulmonary exercise testing (CPET) was performed on a cycle ergometer at baseline and 1 year postoperatively, using standard termination criteria. The SBP response was categorised according to the last measurements of SBP during exercise, in relation to workload (the SBP/watt-slope) as 'normal' (>0.25 mm Hg/watt), 'flat' (0-0.25 mm Hg/watt) or 'drop' (<0 mm Hg/watt)., Results: 45 patients (28 male, 66±9 years, left ventricular ejection fraction 59%±5%, aortic jet velocity 4.6±0.5 m/s) were included, with pairwise comparison available in 31 cases. There were no adverse events. Preoperatively, 4/45 patients were categorised as 'drop', 23 as 'flat' and 18 as 'normal'. There was a change in the distribution of categories from preoperative to postoperative measurements (43% 'normal' vs 74% 'normal', p=0.0046). Maximal SBP and workload-indexed SBP were higher postoperatively than preoperatively (203±26 vs 182±28 mm Hg, p<0.001 and 0.43±0.14 vs 0.29±0.15 mm Hg/watt, p<0.001)., Conclusion: As a drop in SBP was infrequent (<10%) in patients with severe symptomatic AS and no adverse events occurred, our results indicate that CPET may be performed under careful monitoring in AS patients. Postoperatively, the SBP reaction improved, with no patient having a drop in SBP., Trial Registration Number: NCT02790008., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2025. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ Group.)

Background: Treadmill-based gait training is part of rehabilitation programs focused on walking abilities. The use of handrails embedded in treadmill systems is debated, and current literature only explores the issue from a behavioral perspective., Methods: We examined the cortical correlates of treadmill walking in healthy participants using functional near-infrared spectroscopy. We investigated whether the utilization of treadmill handrails at varying walking speeds could affect cortical activation associated with the task, and we evaluated potential differences in task-based functional connectivity across the various walking conditions., Results: Significant differences in cortical activation were found between the two walking speeds (3 and 5 km/h) in the unsupported condition; these differences were reduced when using the handrails. Specifically, cortical activation was significantly higher when the participants swung their arms freely while walking at a speed of 5 compared to 3 km/h in several Brodmann's Areas (BA): left BA10, BA3 and BA39, and right BA10, BA9, BA8, BA3, and BA40. No significant differences were found when participants were holding onto the handrails. A significant difference was found in the left BA40 between the two speeds, regardless of whether the participants were holding onto the handrails. Furthermore, at the higher speed and without the use of handrails, a wider pattern of task-based functional connectivity was observed, with significantly stronger connectivity between the left BA10 and BA40., Conclusions: We suggest that speed and handrails use play a role in walking cortical activity patterns, therefore they are key ingredients to take into account when planning a rehabilitation program., Competing Interests: Declarations. Ethics approval and consent to participate: The study was approved by the University Ethics Committee (CERA), Genoa, Italy (N. 2023/44). The work described has been carried out in accordance with The Code of Ethics of the World Medical Association (Declaration of Helsinki) for experiments involving humans. All participants provided informed consent to participate in the study. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

An example of chemotherapy-induced cardiotoxicity in cancer survivors is acquired long QT syndrome (aLQTS), which may cause serious yet preventable life-threatening consequences. Our objective was to identify and characterize childhood acute lymphoblastic leukemia (ALL) survivors with possible aLQTS using maximal exercise testing. In this cross-sectional study with exploratory analysis, a total of 250 childhood ALL survivors were evaluated for abnormal QT interval prolongation using the McMaster cycle exercise test. A total of 198 survivors (102 males; 96 females), having reached their V ̇ O 2 peak (mean 32.1 ± 8.4 mL/kg/min; range 15.5-57.8 mL/kg/min), were included in our analyses. Two survivors were excluded for possible congenital LQTS. QT intervals were corrected for heart rate using the Bazett, Fridericia, and Rautaharju formulas at rest (supine, sitting, and standing positions), at the end of each stage of the CPET, and at 1, 3, and 5 minutes into the recovery period. The corrected QT (QTc) of borderline (n = 37) and long QT survivors (n = 20) was significantly longer than normal survivors (n = 141) at rest, exercise, and recovery. Out of 57 survivors presenting an abnormal QTc prolongation, 40 survivors (70%) showed no QT interval anomalies at rest but developed various anomalies during exercise. No significant differences were found between the groups for any of the measured clinical characteristics or cardiac parameters. The standardization of exercise testing in the regular follow-up of oncology patients is necessary for appropriate cardiac prevention and surveillance to enhance the health and quality of life of the ever-increasing number of cancer survivors., (© 2024 The Author(s). International Journal of Cancer published by John Wiley & Sons Ltd on behalf of UICC.)

Background: The one-minute sit-to-stand test (1STST) is an easy-to-administer, space and time-saving test for determining functional exercise capacity in cardiac disease. This study aimed to investigate the 1STST -test-retest reliability and convergent validity and compare its physiological responses to the six-minute walk test (6MWT) in patients with Atrial fibrillation (AF)., Methods: Forty-five patients with AF were included in this study. Functional exercise capacity was evaluated using the 1STST and 6MWT. For assessing test-retest reliability, the intraclass correlation coefficient and Bland-Altman plots were utilised. Convergent validity was determined by correlation analysis 1 STST and 6MWT, age, European Heart Rhythm Association score, ejection fraction, and quality of life. The cut-off point of 1STST was defined using ROC analysis., Results: With an intraclass correlation coefficient value of 0.975 [95 % confidence interval (CI) 0.954-0.986], the 1STST demonstrated excellent-test-retest reliability. Physiological responses after tests were similar in the 1STST and 6MWT (p > 0.05). The number of 1STST repetitions was strongly associated with 6MWT distance (r = 0.809; p < 0.001). A cut-off value of ≤13 repetitions in the number of 1STST repetitions was defined as functional impairment related to an increased risk of clinical events [sensitivity: 100 %, specificity: 84.6 %; AUC:0.94; 95 % CI 0.82 to 0.98; p < 0.001]., Conclusions: The 1STST is a reliable and valid assessment tool that produced comparable hemodynamic responses to the 6MWT in patients with AF. Considering its feasibility and time efficiency, healthcare professionals can use the 1STST rather than the 6MWT test to measure functional exercise status in a constrained environment for this patient group., Competing Interests: Declaration of competing interest None., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Exercise Based Cardiac Rehabilitation (EBCR) is highly beneficial to improve the outcome and quality of life of patients suffering from cardiac diseases. Most of the time, it increases cardiorespiratory and muscle capacity. However, not all patients elicit these benefits because of the high variability in their response to EBCR. In this context, the present study aimed to determine the potential of a specific parameter, the Contractility index (CTi), to predict the response of cardiac patients to EBCR. This parameter is acquired during the baseline Cardiopulmonary Exercise Test (CPET), using Signal-Morphology based Impedance Cardiography (SM-ICG TM )., Methods: 58 cardiac patients (59.7 ± 10.2 years old) were retrospectively enrolled in this study and admitted to EBCR, and 57 could be analyzed., Results: The patients were divided into 2 groups based on their CTi response during CPET (normal versus altered or compromised). After the EBCR program, there was an overall increase in peak oxygen uptake (VO 2 peak) (+13.6 ± 22.9 %). EBCR induced a higher VO 2 peak improvement in patients with normal CTi response compared to their counterparts with altered or compromised CTi profiles (+24.1 ± 21.4 % vs. + 3.36 ± 19.5 %, p < 0.01) Patients with a normal CTi response during the baseline CPET were more likely to have a greater than 5% improvement in VO 2 peak (odds ratio 8.7, p = 0.012) and benefit from EBCR, as compared to the patients in the altered or compromised CTi group., Conclusion: This study demonstrated the predictive potential of the CTi profile observed during the baseline CPET to anticipate the response to EBCR in cardiac patients., Competing Interests: Declaration of competing interest Frank Bour is co-inventor of the SM-ICG(TM) technology and co-founder and managing director of Manatec Biomedical, the company that develops and manufactures the PhysioFlow® device based on this technology., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

This study aimed to assess the intraday reliability of markerless gait analysis using an RGB-D camera versus a traditional three-dimensional motion analysis (3DMA) system with and without a simulated walking assistant. Gait assessments were conducted on 20 healthy adults walking on a treadmill with a focus on spatiotemporal parameters gathered using the RGB-D camera and 3DMA system. The intraday reliability of the RGB-D camera was evaluated using intraclass correlation coefficients (ICC 1, 1), while its consistency with the 3DMA system was determined using ICC (2, 1). The results demonstrated that the RGB-D camera provided high intraday reliability and showed strong consistency with 3DMA measurements regardless of the presence of an assistant. The Bland-Atman analysis indicated no significant systematic bias, with the minimum detectable change remaining within acceptable clinical ranges. These findings highlight the potential of the RGB-D camera for reliable markerless gait analysis in clinical environments in which walking assistance may be needed, thereby expanding its applicability in patients with various impairment degrees. Future research should validate these results in patient populations and explore their utility for measuring kinematic parameters.

Background and Objectives : This study aimed to evaluate and compare the functional capacity of post-COVID-19 patients with a control group and analyze cardiac hemodynamics and muscle tissue oxygenation responses during assessment protocols in both groups. Materials and Methods : A cross-sectional study was conducted involving patients with COVID-19 and a control group who were all aged ≥18 years. Participants underwent two functional capacity tests: the one-minute sit-stand test (1-STS) and the six-minute walk test (6MWT). Cardiac hemodynamic responses were evaluated using impedance during the 1-STS, and tissue perfusion responses in the oxygenation were recorded during and after both tests. The Friedman test was used for within-group and the Mann-Whitney test was used for between-group comparisons. Results : Thirty-six post-COVID-19 patients (median age 36 years, BMI 26.51 kg/m 2 ) and eleven control subjects (median age 25 years, BMI 23.71 kg/m 2 ) were enrolled. The post-COVID-19 group showed a 20% decrease in 6MWT distance ( p = 0.0001) and a 28% decrease in 1-STS repetitions ( p = 0.01) versus the control group. Cardiac hemodynamic differences were observed in the post-COVID-19 group during the 1-STS, with reductions in the stroke volume index (18%, p = 0.004), cardiac index (21%, p = 0.0009), Contractility Index (78%, p = 0.0001), and Ejection Fraction (29%, p = 0.0003) and increases in Systemic Vascular Resistance (25%, p = 0.03) and the Systemic Vascular Resistance Index (27%, p = 0.0007). Tissue oxygenation during the 6MWT and 1-STS showed no significant differences between groups. Conclusions : The post-COVID-19 subjects exhibited a reduction in functional capacity, changes in hemodynamic responses related to cardiac and systemic vascular resistance, and a similar pattern of muscle oxygen delivery and consumption in both tests.

Objectives: Law enforcement agencies require minimum fitness standards to safeguard their officers and training staff. Firearms instructors (FI) are expected to maintain the same standards as their operational counterparts. This study aimed to quantify the daily physiological demands placed on FI., Methods: 19 FI (45 ± 5 years) completed occupational tasks whilst wearing heart rate (HR) monitors for a minimum 10 days. Maximal oxygen consumption (VO2max) testing was conducted on FI during a treadmill test (TT) and a multistage shuttle test (ST). Linear regression models were used to model the relationship between VO2 and HR throughout the TT. This model was applied to HR data from occupational tasks to infer oxygen consumption. Repeated Measures ANOVAs were used to compare time spent in VO2max equivalent zones throughout., Results: The VO2max achieved during ST (45.1 ± 5.6 ml/kg/min) was significantly higher than TT (39 ± 3 ml/kg/min) (p = 0.014). Time to exhaustion (TTE) was sooner on ST (06:26 min) compared to TT (13:16 min) (p < .001). FI spent ~85% of occupational time with an oxygen demand ≤20 ml/kg/min (p < .005). The most intense occupational tasks saw FI achieve VO2max ≥30 ml/kg/min, but <40 ml/kg/min., Conclusion: Using ST to assess cardiorespiratory fitness resulted in a quicker TTE and a higher VO2max. Predominantly, FI occupational tasks are low intensity with sporadic exposures requiring a VO2max of >40 ml/kg/min. To safeguard FI from occupational-related cardiorespiratory or long-term health issues, it is intuitive to suggest fitness standards should exceed a VO2max of 40 ml/kg/min., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2025 Warwick 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.)

Walking is one of the most common forms of self-motion in humans. Most humans can walk effortlessly over flat uniform terrain, but also a variety of more challenging surfaces, as they adjust their gait to the demands of the terrain. In this, they rely in part on the perception of their own gait and of when it needs to be adjusted. Here, we investigated how well N = 48 participants detected speed differences between two belts of a split-belt treadmill. As participants walked at a constant speed, we either accelerated or decelerated one of the belts at quasi-random intervals and asked participants to judge their relative speeds in a two-alternative forced-choice task. Using an adaptive psychophysical procedure, we obtained precise perception-threshold estimates for inter-leg speed differences after accelerating or decelerating one belt. We found that most participants could detect even very small speed differences, with mean threshold estimates of just over 7% for both perturbation types. These were relatively stable within, but highly variable across participants. Increased-speed and decreased-speed thresholds were highly correlated, indicating that despite different biomechanics, the detection mechanisms might be similar. This sheds light on how perceiving their own motion helps humans manage interlimb coordination in perturbed walking., Competing Interests: Competing interests: On behalf of all authors, the corresponding author states that there are no competing interests., (© 2025. The Author(s).)

Objective: This study compared the effects of two different warm-up protocols (normal vs. priming) on the oxygen plateau ([Formula: see text]) incidence rate during a ramp test. It also compared the cardiopulmonary responses during the ramp test and subsequent verification phase., Methods: Eleven recreational cyclists performed two experimental visits. The first visit required a normal warm-up (cycling at 50 W for 10 min) followed by the ramp test (30 W.min-1) and supramaximal verification phase with 30 min rest between tests. The second visit required a priming warm-up (cycling at 50 W for 4 min increasing to 70% difference between the gas exchange threshold [GET] and maximum work rate [WRmax] for 6 min) followed by the same protocol as in the first visit. Physiological responses were collected during the exercise and compared. Oxygen kinetics ([Formula: see text] Kinetics) and [Formula: see text] incidence rate were determined during the ramp tests for both visits., Results: As planned, following the warm-up the priming visit experienced greater physiological response. However, the incidence rate of [Formula: see text] during the ramp test was the same between visits (73%), and maximal oxygen uptake was not different between visits after the ramp test (normal, 4.0 ± 0.8; primed, 4.0 ± 0.7 L·min-1, p = 0.230) and verification phase (normal, 3.8 ± 0.6; primed, 3.8 ± 0.7 L·min-1, p = 0.924) using a Holm-Bonferroni correction for controlling family-wise error rate. [Formula: see text] Kinetics were not different between visits during the ramp test (normal, 10.8 ± 1.1; primed, 10.8 ± 1.2 mL·min-1·W-1, p = 0.407). The verification phase confirmed [Formula: see text] in 100% for both the normal and priming visits., Conclusion: Our hypothesis that a priming warm-up facilitates the incidence rate of [Formula: see text] during a ramp test is not supported by the results. The verification phase remains a prudent option when determining a 'true' [Formula: see text] is required., Competing Interests: The authors have declared that no competing interests exist., (Copyright: This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.)

This study evaluated the influence of cycle computers on the accuracy of power and cadence data. The research was divided into three phases: (1) a graded exercise test (GXT) at different constant loads to record power and cadence data; (2) a self-paced effort lasting 1 min to measure mean maximal power output (MMP); and (3) a short all-out effort. Eight cyclists completed the GXT, ten participated in the 1-min test, and thirty participated in the sprint effort. All participants pedaled on a controlled-resistance cycle ergometer, and the data were recorded using the ergometer itself and ten synchronized cycle computers of the same brand, configured to record at 1 Hz. The results showed minimal variations in power and cadence between devices during the GXT, suggesting adequate accuracy for constant efforts lasting a certain duration. However, in self-paced and high-intensity efforts (1-min and short all-out efforts), significant differences were observed between several devices, particularly in cadence and mean power, highlighting the relevance of device selection in these contexts. These findings suggest that, while variations in constant efforts may be negligible, in short-duration, high-intensity activities, the choice of device may be crucial for the accuracy and reliability of the data.

Introduction: As wearable technology becomes increasingly popular and sophisticated, independent validation is needed to determine its accuracy and potential applications. Therefore, the purpose of this study was to evaluate the accuracy (validity) of VO2max estimates and blood oxygen saturation measured via pulse oximetry using the Garmin fēnix 6 with a general population participant pool., Methods: We recruited apparently healthy individuals (both active and sedentary) for VO2max (n = 19) and pulse oximetry testing (n = 22). VO2max was assessed through a graded exercise test and an outdoor run, comparing results from the Garmin fēnix 6 to a criterion measurement obtained from a metabolic system. Pulse oximetry involved comparing fēnix 6 readings under normoxic and hypoxic conditions against a medical-grade pulse oximeter. Data analysis included descriptive statistics, error analysis, correlation analysis, equivalence testing, and bias assessment, with the validation criteria set at a concordance correlation coefficient (CCC) > 0.7 and a mean absolute percentage error (MAPE) < 10%., Results: The Garmin fēnix 6 provided accurate VO2max estimates, closely aligning with the 15 s and 30 s averaged laboratory data (MAPE for 30 s avg = 7.05%; Lin's concordance correlation coefficient for 30 s avg = 0.73). However, it failed to accurately measure blood oxygen saturation (BOS) under any condition or combined analysis (MAPE for combined conditions BOS = 4.29%; Lin's concordance correlation coefficient for combined conditions BOS = 0.10)., Conclusion: While the Garmin fēnix 6 shows promise for estimating the VO2max, reflecting its utility for both individuals and researchers, it falls short in accurately measuring BOS, limiting its application for monitoring acclimatization and managing pulmonary diseases. This research underscores the importance of validating wearable technology to leverage its full potential in enhancing personal health and advancing public health research.

People with peripheral arterial disease (PAD) and intermittent claudication (IC) experience impaired walking due to an imbalance between muscle oxygen supply and demand during exercise. Studies with near-infrared spectroscopy (NIRS) during treadmill tests reveal notable tissue deoxygenation with slow recovery. This cross-sectional study aimed to compare behavior of calf muscle oxygenation during the incremental shuttle walking test (ISWT) with a continuous treadmill test (3.2 km/h, 10% incline) and to correlate NIRS results between tests in PAD patients. Sixty individuals with IC, 37 men (61.7%), mean age 66.25 ± 10.35 years participated in the study. Both tests were performed on the same day with a 30-minute rest, in randomized order. NIRS-derived calf muscle tissue oxygenation variables were measured at rest and during exercise. Typical PAD tissue oxygenation patterns were observed in both tests, with significant differences (p < 0.05) in oxygenation values during exercise for the variables delta of tissue oxygen saturation (ΔStO 2 ) and reoxygenation rates. All tissue oxygenation variables analyzed, except reoxygenation rate, showed a significant and directly proportional correlation between the two tests. These results suggest that NIRS during ISWT could be a viable method for assessing tissue oxygenation in PAD., Competing Interests: Declarations. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Cardiorespiratory fitness is the most important variable related to health and a strong predictor of mortality. However, it is rarely used in clinics due to costs, specialized equipment, space needs, and the requirements of expert staff such as an exercise physiologist, physician, or other health professional. This work aims to validate and test the reliability of a submaximal step test to estimate VO 2 max of 8-to 16-year-old pediatric populations as a simple and low-cost tool for clinical practice. A cross-sectional study included 242 children and adolescents (42.1% girls) aged 8-16. Cardiorespiratory fitness was determined by a maximal incremental test on a treadmill until exhaustion. The step test entailed maintaining a steady pace of 22 steps per minute for 3 min (60 bpm), with the heart rate being recorded at the end of the test. Nutritional status was computed through BMI z-score. A multiple linear regression model validated the step test and developed a new equation to predict VO 2 max, including the third-minute heart rate, weight, and height. The reliability among predicted and measured VO 2 max was assessed by Bland-Altman analysis. The mean age was 12.5 ± 2.6; 51.6% were overweight or obese. The cardiorespiratory fitness measured as VO 2 max was 35.01 ± 0.58 ml·min- 1 ·kg -1 . A robust correlation was observed between the predicted VO 2 max from the step test and the measured VO 2 max (r = 0.86, p < 0.001). Bland-Altman analysis indicated statistical concordance between predicted and measured VO 2 max. Our findings indicate that the step test protocol is valid and reliable for estimating VO 2 max in children and adolescents. Furthermore, the predictive equation is suitable for application among children aged 8-16., Competing Interests: Declarations. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

This study investigated sex differences in the development of pulmonary edema and exercise-induced arterial hypoxemia (EIAH) in well-trained endurance athletes during near-maximal exercise in a real-world setting. Twenty participants (10M vs. 10F; V̇O 2 peak: 69.3 (8.8) vs. 50.7 (4.1) ml∙kg -1 ∙min -1 ) underwent a maximal incremental treadmill test (visit 1) and a time trial on a steep trail (~2.5 km, ~800 m elevation gain) in North Vancouver (visit 2). Pulmonary edema was evaluated using handheld lung ultrasound ~10-15 min post-exercise and oxygen saturation (SpO 2 ) was monitored using finger pulse oximetry. Males completed the time trial significantly faster than females (M: 31.5 (6.5) vs. F: 40.4 (7.5) min, p = 0.006), while females sustained a higher percentage of their visit 1 heart rate (M: 94 (1) vs. F: 96 (1) %max, p = 0.02). All participants developed EIAH, with no sex differences in end-exercise SpO 2 (M: 89 (4) % vs. F: 90 (3) %, respectively, p = 0.35). There was no evidence of pulmonary edema, assessed through ultrasound b-line scores, with no differences between sexes (M: 0.3 (1.0) vs. F: 0.5 (1.5), respectively, p = 0.60). Pulmonary edema is an unlikely contributor to EIAH in endurance athletes performing near-maximal time trial exercise in a real-world setting., (© 2025 The Author(s). Physiological Reports published by Wiley Periodicals LLC on behalf of The Physiological Society and the American Physiological Society.)

Objectives: To assess the safety, reliability and acceptability of the modified incremental step test (MIST) supervised remotely via videoconferencing in adults with chronic respiratory disease., Methods: Adults with chronic respiratory disease undertaking pulmonary rehabilitation were invited to undertake the MIST under two testing conditions: in-person supervision and remote supervision via video-conferencing. Test order was randomised., Results: 38 participants ( n = 18 Female; mean (SD) age 68 (10) years; 56% chronic obstructive pulmonary disease) undertook two MIST evaluations. There was excellent agreement between tests for total step count (ICC 2,1 0.93, 95%CI 0.86 to 0.96), despite higher counts with in-person supervision (MD 12 steps, 95%CI 1 to 24). There was very good agreement, and no difference between tests, for nadir oxygen saturation (ICC 2,1 0.797, 95%CI 0.643 to 0.889) and peak heart rate (ICC 2,1 0.782, 95%CI 0.620 to 0.880). Participant satisfaction with telehealth was high, and confidence was not different between testing conditions. There were no adverse events and remote testing was acceptable to participants., Discussion: In this single centre cohort study MIST supervised remotely via video-conferencing was safe, reliable and acceptable to people with chronic respiratory disease., 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.

Background: Cardiopulmonary exercise testing (CPET) is usually considered the gold standard for assessing maximal oxygen consumption (V̇O 2max ), a health and performance marker in patients with chronic obstructive pulmonary disease (COPD). Despite the widespread application of CPET, the absolute and relative test-retest reliability of CPET-derived metrics remains unexamined., Objective: To examine and compare test-retest reliability of CPET derived metrics in individuals with COPD and healthy matched controls., Methods: 12 individuals with COPD and 12 healthy age- and sex-matched controls were included in this case-control study. Each participant completed two CPET on a bicycle ergometer on two different days. Absolute reliability was reported as smallest real difference (SRD) and relative reliability as coefficient of variance (CV) and intraclass correlation coefficients (ICC)., Main Results: SRD for peak oxygen uptake was 451.6 (267.4;1006.4) mL/min and CV was 7.8 (4.7;11.0)% in patients with COPD, whereas SRD was 244.2 (151.4;491.5) mL/min and CV was 3.0 (1.8;4.2)% in healthy controls but with no significant between group difference for SRD. CV values for all CPET derived metrics were found to be below 10%. Apart from peak workload achieved and peak minute ventilation, SRD and CV were significantly higher in COPD than in controls for all other CPET-derived metrics., Conclusion: This study provides test-retest reliability estimates of the most widely used CPET derived metrics in individuals with COPD and healthy matched controls. Test-retest reliability for most metrics derived from CPET were found to be lower in individuals with COPD when compared to healthy controls., (© 2025 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.)

Maximal oxygen uptake (VO 2 max) in healthy subjects is primarily limited by systemic oxygen delivery. In chronic kidney disease (CKD), VO 2 max is potentially reduced by both central and peripheral factors. We aimed to investigate the effect on VO 2 peak of adding arm exercise to leg exercise. Ten individuals with CKD stages 3-5 and 10 healthy controls, matched for age, sex, body size, and physical activity level, were included. Subjects performed two maximal exercise tests, one with legs only (L exercise) and one test where arm exercise was added to leg exercise (LA exercise). The increase in VO 2 peak, when comparing LA exercise with L exercise, was significantly higher in CKD (0.20 ± 0.18 L/min or 2.31 ± 1.78 mL/(kg·min)) than in controls (0.019 ± 0.12 L/min or 0.26 ± 1.62 mL/(kg·min); p = 0.02 and 0.01, respectively). The decrease in peak leg workload, when comparing L exercise with LA exercise, was larger in controls than in CKD, in absolute terms (p = 0.002) and relative to body weight (p = 0.01). VO 2 max in individuals with CKD is dependent on the active muscle mass, supporting a peripheral limitation to VO 2 max in CKD. By contrast, the control group appeared to have a more central limitation to VO 2 max., (© 2025 The Author(s). Physiological Reports published by Wiley Periodicals LLC on behalf of The Physiological Society and the American Physiological Society.)

Given the growing concern over the impact of brain health in individuals with overweight, understanding how mental exertion (ME) during exercise affects substrate oxidation and cardiorespiratory outcomes is crucial. This study examines how ME impacts these outcomes during an incremental exercise test in adults with overweight. Seventeen adults who were overweight completed an incremental exercise test on a cycle ergometer two times, with and without the Stroop task. Energy expenditure (EE), carbohydrate and fat oxidation, maximum heart rate (HR max ), maximal oxygen uptake (VO2 max ), maximum fat oxidation (MFO), and the intensity of exercise that elicited MFO (Fat max ) are measured by indirect calorimetry. ME did not change the EE, carbohydrate, and fat oxidation at any stages of the incremental test. However, ME resulted in significantly lower HR max , VO2 max , and MFO (p < 0.01) and increased NASA-TLX scores but showed no change in Fat max . These results show ME decreases the value of HR max , VO2 max , and MFO during the incremental exercise test. Due to the increased mental workload demonstrated by the NASA-TLX test, adults with overweight are unable to complete the test to the same extent as they did in the test without ME according to maximal levels in this study., (© 2025 The Author(s). Physiological Reports published by Wiley Periodicals LLC on behalf of The Physiological Society and the American Physiological Society.)

Objective: In this feasibility study, firstly, we aimed to assess whether intramuscular pH (IMpH) could be measured with a glass-tipped electrode. Secondly, we aimed to explore whether we could monitor changes in skeletal muscle pH before and throughout static (isometric) and after dynamic (treadmill) exercise, comparing individuals with intermittent claudication (IC) to a group of healthy controls., Methods: Forty participants with IC (mean age ± SD) 68 ± 8) and 40 healthy volunteers (63 ± 10) were recruited. Participants in the IC group had an ankle brachial pressure index of <0.7 (mean: 0.62 ± 0.13). The first 20 participants in each group underwent isometric ankle dorsiflexion for 120 s at 30% of maximum voluntary contraction and the remainder underwent treadmill exercise (3.6 km/h, 5° incline) to maximal walking distance. A sterilised reusable 1.5 mm shatterproof, heat strengthened glass tipped pH probe inserted using a peripheral venous cannula and in combination with a pH meter was used to measure IMpH of the tibialis anterior muscle prior to, during and continuously for 1 h after exercise., Results: Resting IMpH was similar between the groups (median 6.8 (interquartile range (IQR) 6.7-6.9)) for IC individuals and 6.7 (6.6 to 6.8) for controls). Following isometric exercise, the magnitude of the decrease in IMpH was greatest in the IC group (median ΔpH max. in patients -0.2 (IQR: -0.2 to -0.1) versus -0.1 (IQR: -0.2 to -0.1) in the control group ( p =  0.002). After treadmill exercise, the magnitude of the decrease in IMpH (ΔpH max) was greatest in individuals with IC (median ΔpH max. in patients -0.3 (IQR: -0.3 to -0.3) versus 0 (IQR: -0.2 to 0) in the control group, p =  0.04., Conclusions: IMpH monitoring with a flexible glass probe inserted into the tibialis anterior muscle is viable and changes in IMpH during static and dynamic exercises are detected., Competing Interests: Declaration of conflicting interestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Exercise testing is frequently incorporated into management of patients with cardiovascular and/or pulmonary disease. A lifelong commitment to exercise promotes cardiac remodeling, leading to changes in structure and function of the atria and ventricles, commonly referred to as the "athletic heart." Stress testing is also incorporated into the management of athletes for a variety of reasons, such as identifying the cause of exertional symptoms, determining level of fitness and training zones, or assessing for acquired cardiomyopathies. Exercise testing should be tailored to the athlete, since performance may vary from other populations as a result of a commitment to exercise training., Competing Interests: Disclosure None., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Cardiopulmonary exercise testing is an active research area in patients with unexplained dyspnea, heart failure, and pulmonary hypertension. Focus has centered on the use of novel hemodynamic parameters to further characterize these disease states, influence therapeutics, and determine prognosis. Translational research focuses on the underlying cardiopulmonary physiology to more precisely quantify the effect of pulmonary vascular disease on the right ventricle and pulmonary function/hemodynamics. In addition, phenotyping unexplained dyspnea is of critical importance, given the significant heterogeneity of this patient population with implications for therapies and clinical trial design., Competing Interests: Disclosure The authors have no disclosures., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Pulmonary arterial hypertension (PAH) is a progressive pulmonary vascular disease that has a high impact on patients' quality of life, morbidity and mortality. PAH is characterized by extensive pulmonary vascular remodeling that results in an increase in pulmonary vascular resistance and right ventricular afterload, and can lead to right heart failure. Patients with PAH exhibit inefficient ventilation, high dead space ventilation, dynamic hyperinflation, and ventricular-arterial uncoupling, which can contribute to high dyspnea and low exercise tolerance. Cardiopulmonary exercise testing can help to diagnose PAH, define prognosis and treatment response in PAH, as well as discriminate between different pulmonary vascular diseases., Competing Interests: Disclosure K. Dmytriiev has nothing to disclose; M.K. Stickland has nothing to disclose, J. Weatherald has received grants or contracts to his institution from Astra Zeneca, Bayer, Janssen, Sanofi, and Merck; consulting fees from Janssen and Merck; honoraria from Janssen and Merck; advisory board payments from Janssen and Merck, payment for expert testimony from Sprigings Intellectual Property Law; travel support from Janssen; participation on Data Safety and Monitoring Board for the Université de Laval; and has unpaid leadership role at the Pulmonary Hypertension Association of Canada., (Copyright © 2024 Elsevier Inc. All rights reserved.)

This study aimed to evaluate the applicability of the 10-minute submaximal treadmill test (T10 test), a self-paced test, in determining critical speed (CS) and predicting running performance. Specifically, we sought to identify the percentage of T10 velocity (vT10) that runners performed in official distance races, and to compare physiological and performance indicators between sexes. 60 recreational runners (n=34 males and n=26 females) underwent a maximum incremental test, the novel T10 test, and ran 1200-m and 2400-m on the track. Runners self-reported their best performance times. Generalized Linear Model was used to compare running performances between sexes. For both males and females, the %vT10 in 5 km, 10 km, and half-marathon races occurred at 107.5% and 106.5%, 99.9% and 100.8%, and 92.6% and 97.1%, respectively. There was no interaction effect (p=0.520) and no main effect of sex (p=0.443). There was a main effect of distance (p<0.001), indicating that %vT10 in the 5km race differed from that found in the 10 km race (p=0.012), as well as in the half-marathon (p<0.001). Our findings suggest that %vT10 values can be used to determine pace in recreational endurance runners for race distances regardless of sex., Competing Interests: The authors declare that they have no conflict of interest., (Thieme. All rights reserved.)

Purpose: Fat free mass (FFM) is considered the metabolically active component of human body and is positively associated with maximal oxygen uptake ( VO 2 max ). However, FFM is composed of metabolically active and inactive subcomponents whose proportion can vary depending on body composition and clinical condition, possibly affecting such association. Although it is known that in facioscapulohumeral dystrophy (FSHD) peculiar changes in body composition occur, it is unclear whether there are alterations in FFM composition and, if so, whether such alterations affect the association towards VO 2 max compared to healthy subjects (HS)., Methods: To address this issue, 27 FSHD patients (mean age 37.3; 9 female) and 27 sex and age matched HS, underwent an assessment of VO 2 max by cardiopulmonary exercise tests (CPET) and body composition, with reference to FFM and its subcomponents, by bioimpedance analysis., Results: In between-groups comparison, patients showed lower amounts of body cell mass (BCM) and intracellular water (ICW) which reflect in lower BCM/FFM ratio and higher extracellular to intracellular water ratio (ECW/ICW). Patients' VO 2 max was lower than HS and, even if with lower associative values than HS, correlated with FFM and BCM, while BCM/FFM and ECW/ICW ratios associations were observed only in HS., Conclusion: FSHD patients showed lower amount of BCM and ICW. BCM resulted as the parameter with the highest associative value with VO2max in both groups. Since VO 2 max is associated with functional ability in dystrophic patients, BCM, rather than FFM, could be an additional body composition-based clinical stratification factor., Competing Interests: Declarations. Conflict of interest: None of the authors has any conflict of interest to disclose., (© 2024. The Author(s).)

Long-term exercise intolerance and functional limitations are common after an episode of acute pulmonary embolism (PE), despite 3 to 6 months of anticoagulation. These persistent symptoms are reported in more than half of the patients with acute PE and are referred as "post-PE syndrome." Although these functional limitations can occur from persistent pulmonary vascular occlusion or pulmonary vascular remodeling, significant deconditioning can be a major contributing factor. Herein, the authors review the role of exercise testing to elucidate the mechanisms of exercise limitations to guide next steps in management and exercise training for musculoskeletal deconditioning., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The American College of Sports Medicine determined the energy consumption of daily activities and sports. Cardiac telerehabilitation (CTR) requires knowing how much energy people consume in daily life outside of cardiac rehabilitation activities. Therefore, we have investigated if the estimated values are valid in CTR. Data from two studies were incorporated. The first study measured ventilatory threshold (VT)1, VT2, and peak exercise on cardiopulmonary exercise testing (CPET) collected from 272 cardiac (risk) patients and compared them to the estimated oxygen consumption (VO 2 ) at low-to-moderate-intense exercise (3-6 metabolic equivalents [METs]). Next, a patient-tailored application was developed to support CTR using these estimated values, and the intervention (the second study) was conducted with 24 coronary artery disease patients using this application during a CTR intervention. In the first study, VO 2 at VT1, VT2 and peak exercise corresponded to 3.2 [2.8, 3.8], 4.3 [3.8, 5.3], and 5.4 [4.5, 6.2] METs, which are significantly different from the estimated VO 2 at low-to-moderate-intense exercise, especially lower in older, obese, female, and post-myocardial infarction/heart failure patients. These VO 2 varied considerably between patients. The telerehabilitation study did not show significant progress in peak VO 2 , but using the application's estimated target, 97.2% of the patients achieved their weekly target, which is a significant overestimate. The estimated and observed exercise-related energy expenditures by CPET were significantly different, resulting in an overestimation of the exercise done by the patients at home. The results can have a significant impact on the quantification of exercise dose during (tele)rehabilitation programs., 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.

Background: Exercise electrocardiogram (ECG) is frequently used for evaluating patients with suspected coronary artery disease (CAD). However, it has been downgraded in international guidelines due to a limited sensitivity and specificity, compared with other non-invasive tests., Methods: We hypothesized, that a sufficient exertion going beyond 85% of the age predicted maximal heart rate (APMHR), by considering the achieved level of workload can improve sensitivity and specificity of the exercise ECG. Secondly, the performance of exercise ECG, when evaluated against a functional reference standard has barely been investigated, although an improved diagnostic accuracy has been reported for other non-invasive tests in this case. Therefore, in this pilot study, a total of 147 patients without known CAD who underwent exercise ECG followed by coronary angiography within 90 days were retrospectively evaluated., Results: The combined end point of 85% of APMHR and 75% of the predicted workload showed a slight but not statistically significant benefit over APMHR alone (66.7% vs. 58.1%; p = 0.545). The sensitivity of ST-segment depression was 51.3% for detecting anatomically defined CAD and 62.5% for functionally relevant CAD (p = 0.378)., Conclusions: Although the results of this pilot study lack statistical significance, the numeric differences clearly justify further research on this topic., (© 2024 The Author(s). Annals of Noninvasive Electrocardiology published by Wiley Periodicals LLC.)

Introduction: Survivors of severe COVID-19 face complex challenges and a high degree of pulmonary sequelae. Therefore, we aim to describe their ongoing health burden., Methods: In this single-center prospective cohort study, COVID-19 ICU survivors were invited 3 and 6 months after ICU discharge. We examined pulmonary function with pulmonary function tests (PFT) and cardiopulmonary exercise testing (CPET), and we established health-related quality of life (HRQL) and health status (HS) with the EuroQol five-dimension five-level (EQ-5D-5L), the short-form health survey 12 (SF-12), and the modified British Medical Research Council dyspnea scale (mMRC) questionnaires., Results: Out of the 53 individuals screened, 23 participated in this study. Throughout both assessment points, participants maintained PFT results within range, apart from a decline in the transfer factor of the lung for carbon monoxide (TLCO). CPET showed improved fitness but persistent ventilatory deficiencies, indicated by altered dead space ventilation (VD/VT) and elevated arterial-alveoli gradient for oxygen (AaDO2). HRQL and HS remained compromised, with both physical (PCS) and mental component summary (MCS) scores significantly lower than the standardized norm population scores. Also, there was a rise in the prevalence of issues related to mobility, pain/discomfort, and anxiety/depression, and an increase in reported dyspnea., Conclusion: These results enhance our comprehension of the complex difficulties faced by COVID-19 ICU survivors. Six months post-discharge, CPET revealed the presence of ventilatory insufficiencies. Additionally, there was a decline in HRQL and HS, notably affected by mental health concerns and an increase in the level of dyspnea., (© 2024 S. Karger AG, Basel.)

Purpose: Previous studies have shown delayed cardiac vagal reactivation after high-intensity endurance exercise when estimated with heart rate variability (HRV). However, the recovery dynamics of RR intervals (RRI) and HRV after a maximal incremental exercise test have been studied less in non-athletic population and especially in females. The main aim of the study was to examine the recovery dynamics of RRI and HRV immediately after a maximal cardiopulmonary exercise test (CPET) in adult females., Methods: Twenty-eight healthy, novice recreational female runners (33.7 ± 4.2 years) were selected to participate in this study from a larger group of participants (Run RCT). RRIs were collected continuously during a controlled rest, a CPET on a treadmill and a 15-min controlled, passive recovery. Minute-by-minute recovery dynamics were analyzed., Results: The dynamic phase of RRI and heart rate recovery (HRR) (from 192.2 ± 9.9 to 111.4 ± 2.4, P < 0.001) occurred during the first 4.5 min with HRR of 36 ± 10 beats during the first minute of the recovery. Resting heart rate was negatively associated (r =  - 0.53, P = 0.016) with HRR during the recovery. No recovery of root mean square of successive RRIs (RMSSD) was detected during the 15-min recovery. RMSSD was 15.0 ± 9.2% of resting values at the end of the recovery., Conclusion: No recovery of vagal-derived HRV was detected immediately after a CPET in novice recreational female runners despite marked changes in sympathovagal balance, detected by rapid recovery of RRI during the first 5 min after exercise cessation., Competing Interests: Declarations. Conflict of interest: Authors have no competing interests to declare., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: COPD is characterized by reduced exercise tolerance, and improving physical performance is an important therapeutic goal. A variety of exercise tests are commonly used to assess exercise tolerance, including laboratory and field-based tests. The responsiveness of these various tests to common COPD interventions is yet to be compared, but the results may inform test selection in clinical and research settings., Research Question: What exercise test possesses the greatest sensitivity to change from before to after intervention in patients with COPD?, Study Design and Methods: One hundred fifty-four patients with symptomatic COPD were recruited and randomized (2:1:1) to 6 weeks of long-acting muscarinic antagonist, pulmonary rehabilitation (PR), or usual care. Before and after intervention, participants performed an incremental cycle exercise test and constant work rate cycle test (CWRCT), incremental shuttle walk test and endurance shuttle walk test (ESWT), 6-min walk test, and 4-m gait speed test., Results: One hundred three participants (mean ± SD age, 67 ± 8 years; 75 male participants [73%]; FEV 1 , 50.6 ± 16.8% predicted) completed the study. Significant improvements in the incremental cycle exercise test, CWRCT, incremental cycle exercise test, ESWT, and 6-min walk test results were observed after PR (P < .05), with the greatest improvements seen in the constant work rate protocols (percentages change: CWRCT, 42%; ESWT, 41%)., Interpretation: The ESWT and CWRCT seemed to be the most responsive exercise test protocols to long-acting muscarinic antagonist and PR therapy. The magnitude of change was much greater after a program of rehabilitation compared with bronchodilator therapy., Clinical Trial Registry: International Standard Randomised Controlled Trial Number (ISRCTN): No. 64759523; URL: https://www.isrctn.com/ISRCTN64759523., Competing Interests: Financial/Nonfinancial Disclosures The authors have reported to CHEST the following: R. T.-S. is a retiree and shareholder of GlaxoSmithKline since 2019. M. A. is a former employee of GlaxoSmithKline. A.H is a former employee of Boehringer Ingelheim (Canada) Ltd. M. C. S reports personal fees and non-financial support from Boehringer Ingelheim and GlaxoSmithKline, outside the submitted work. None declared (T. C.H.-D., M. M. B, M. I. P, M. R, S. A. E, M. D. M, S. J. S)., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

The short-term scaling exponent of detrended fluctuation analysis (DFAα1) applied to interbeat intervals may provide a method to identify ventilatory thresholds and indicate systemic perturbation during prolonged exercise. The purposes of this study were to (i) identify the gas exchange threshold (GET) and respiratory compensation point (RCP) using DFAα1 values of 0.75 and 0.5 from incremental exercise, (ii) compare DFAα1 thresholds with DFAα1 measures during constant-speed running near the maximal lactate steady state (MLSS), and (iii) assess the repeatability of DFAα1 between MLSS trials. Twelve runners performed an incremental running test and constant-speed running 5% below, at, and 5% above the MLSS, plus a repeat trial at MLSS. During 30-min running trials near MLSS, DFAα1 responses were variable (i.e., 0.27-1.24) and affected by intensity (p = 0.031) and duration (p = 0.003). No difference in DFAα1 was detected between MLSS trials (p = 0.597). In the early phase (~ 8 min), DFAα1 measures at MLSS (0.71 [0.13]) remained higher than the DFAα1 identified at RCP from the incremental test (0.57 [0.13]; p = 0.024). In addition, following ~ 18 min of constant speed running at MLSS, DFAα1 measures (0.64 [0.14]) remained higher than 0.5 (p = 0.011)-the value thought to demarcate the boundaries between heavy and severe exercise intensities. Accordingly, using fixed DFAα1 values associated with the RCP from incremental exercise to guide constant-speed exercise training may produce a greater than expected exercise intensity, however; the dependency of DFAα1 on intensity and duration suggest its potential utility to quantify systemic perturbations imposed by continuous exercise., Competing Interests: Declarations. Conflict of interest: MR is the founder of the software application used for data processing, AI Endurance ( https://aiendurance.com ). All other authors declare no conflicts of interest., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The study of split-belt treadmill adaptation provides insight into the priorities determining how we adapt to novel conditions during walking. During split-belt adaptation, young adults reduce their metabolic cost and positive leg work in part by learning to take longer steps on the fast belt, thus adopting a positive step length asymmetry. However, aging may lead to a shift in the work performed by distal versus proximal joints, so it is unknown if older adults can similarly reduce the work performed by the legs during split-belt walking. Therefore, we quantified the relationship between joint work rate and step length asymmetry when fourteen older adults walked on a split-belt treadmill. We hypothesized that total positive joint work would decrease at more positive step length asymmetries and that more positive asymmetries would be associated with a reduction in positive ankle joint work on the fast belt. We found that step length asymmetry was negatively correlated with total positive work (p = 0.01) and that changes in positive joint work were primarily driven by positive ankle work on the fast belt (p = 0.01). Since ankle musculature is hypothesized to be a major contributor to metabolic cost during gait, reductions in ankle joint work likely contribute to the reduction in metabolic cost observed in other studies of split-belt walking. These results demonstrate that healthy aging still allows individuals to take advantage of the work performed by the treadmill to reduce the mechanical energy cost of walking., 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. Published by Elsevier Ltd.)

Perioperative exercise interventions have been shown to mitigate morbidity associated with lung resection. While these interventions have established a role in this patient population, there has been little discussion regarding which metrics are used to standardize perioperative exercise interventions. A better understanding of these metrics is needed to define best practices and ensure interventions are reproducible. A systematic review of the literature was performed using CINAHL, PubMed/MEDLINE, and SCOPUS. The initial review yielded a total of 3456 results. After review of titles and abstracts, 119 studies remained. The included studies underwent detailed review of the manuscript and 29 were found to meet the inclusion criteria for the review. A total of 29 studies were selected for inclusion. Included studies were completed on adult patients with diagnosis of lung cancer who underwent lung resection surgery and participated in a standardized exercise intervention before or after their surgery. The most common metrics used to grade exercise interventions were percent maximal workload (%Wmax) based on preoperative cardiopulmonary exercise testing (CPET), which was used in 41% of included studies, and symptom limited Borg rating of perceived exertion, which was used in 38% of included studies. There was significant variation in metrics used for tracking perioperative exercise interventions. Standardization of validated metrics for perioperative exercise interventions, specifically using percent of maximal workload and the Borg scale, would impact the ability to compare future studies and the effectiveness of exercise interventions., Competing Interests: Disclosure The authors have stated that they have no conflicts of interest., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Purpose: The objective of this study was to assess the effect of exercise-based cardiac rehabilitation (CR) with individualized exercise prescription in patients with chronic heart failure (HF) undergoing transcatheter aortic valve replacement (TAVR) in a randomized controlled trial., Methods: A total of 60 patients with chronic HF who received TAVR treatment were randomly divided into the control group (n = 30) and exercise training (ET) group (n = 30). The control group was treated with conventional rehabilitation, and the ET group was given personalized exercise-based CR based on a cardiopulmonary exercise test (CPX). The CPX parameters, echocardiography, 6-minute walk test distance, and quality of life were evaluated in the two groups., Results: All patients who completed symptom-restricted CPX showed no complications. After the 12-week rehabilitation period, the levels of anaerobic threshold, peak oxygen uptake, peak oxygen pulse, peak power, left ventricular ejection fraction, and 6-minute walk test distance in the ET group were significantly higher than those in the control group ( P  < .05). Scores on the Minnesota Life with Heart Failure Questionnaire in the ET group were lower than those in the control group ( P < .05)., Conclusion: Exercise-based CR significantly improves cardiopulmonary function, exercise tolerance, and quality of life in patients with chronic HF who undergo TAVR., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2025 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: Professional boxing is a sport that requires a high aerobic capacity to prevent fatigue and allow athletes to perform over 4-12 rounds. Typically, athletes will go into a heavy training period in a pre-bout camp lasting 6 to 9 weeks. This study investigates the impact of 3 weeks of repeated Wingate sprint interval training, performed on standard gym ergometer bikes, on skeletal muscle endurance and mitochondrial function., Methods: Ten male professional boxers (age: 26 ± 4 years, height: 175 ± 5 cm, weight: 70 ± 5 kg) participated in the study. Baseline testing involved a NIRS monitor attached to the rectus femoris muscle prior to an incremental time to exhaustion test on a treadmill. After the treadmill test participants underwent a series of arterial occlusions to determine mitochondrial function post-volitional exhaustion. Participants then continued their own training for 3 weeks and then repeated baseline testing. After the second testing session, participants undertook three weekly sprint sessions consisting of 3 × 30 s maximal sprints with 60 s recovery. Testing was repeated 3 weeks later., Results: The time to exhaustion increased by > 6% after 3 weeks of sprint interval training as compared to baseline and control (p < 0.05). Skeletal muscle oxygen saturation (SmO 2 ) at exhaustion was increased by 5.5% after 3 weeks of sprint interval training as compared to baseline and control (p = 0.008). Skeletal muscle mitochondrial rate post exhaustion was increased by 160% after 3 weeks of sprint interval training as compared to baseline and control (p < 0.001)., Conclusion: The study demonstrated that SIT led to increased incremental time to exhaustion, higher SmO 2 levels at volitional exhaustion and increased mitochondrial rates in professional boxers. These findings suggest that SIT should be an integral part of a boxe's conditioning regimen to improve performance and safety within the ring., Competing Interests: Declarations. Conflict of interest: No potential conflict of interest was reported by the authors. Ethical approval: Approval was obtained from the research ethics committee of Abertay University. The procedures used in this study adhere to the tenets of the Declaration of Helsinki with participants informed verbally and in writing about the study before giving their informed consent., (© 2024. The Author(s).)

Background: Stair climbing test (SCT) and gait speed test (GST) are two physical performance measures, both of which are associated with postoperative outcomes. However, few studies have compared these two tests for the prognostic value., Methods: A prospective study was conducted in patients undergoing radical gastrectomy for gastric cancer. Handgrip strength (HGS) test, 7-steps SCT and 6-m GST were performed before surgery. Body compositions were analyzed using abdominal computed tomography (CT). Sarcopenia was diagnosed by low HGS plus either low muscle mass or quality., Results: A total of 548 patients were included in this study. Time of GST and SCT were both significantly correlated with HGS, skeletal muscle index and skeletal muscle density, but not with subcutaneous or visceral fat area. Low SCT performance (SCT time ≥12.65s) was associated with higher incidence of postoperative complications and longer postoperative length of stay, whereas low GST performance (GST time ≥5.45s) did not. Low performance in SCT and GST were both associated with worse overall survival (OS) and disease-free survival (DFS) after surgery. Low SCT performance was an independent predictor for postoperative complications, OS, and DFS, whereas low GST performance was not significant in multivariate analyses adjusting for the same covariates. The combination of sarcopenia with low SCT performance showed higher accuracy in predicting postoperative complications and mortality compared with sarcopenia combined with low GST performance., Conclusion: SCT outperformed GST in predicting outcomes after radical gastrectomy for gastric cancer, either as a singular indicator or in combination with sarcopenia assessments., 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, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.)

Purpose: To evaluate the significance of body surface area-to-mass ratio (BSA/mass) on the heat-tolerance test (HTT) results. We hypothesized that individuals defined as heat tolerant (HT) would have on average higher BSA/mass compared with heat intolerant (HI) individuals., Methods: A retrospective reanalysis of the HTT results of 517 soldiers (age, 18-38 yr; M/F, 96%:4%), who were tested by the Israel Defense Forces HTT protocol. The criterion for heat tolerance in the current analysis was a rectal temperature (T re ) plateau during the second hour of the test. A logistic regression analysis to evaluate the predictive power of BSA/mass for heat intolerance was performed; the spline model was applied to show the odds for heat intolerance across BSA/mass., Results: In men BSA/mass of HI individuals was lower than HT individuals (248 ± 19 vs 262 ± 18 cm 2 ·kg -1 , P < 0.01, d = 0.76). In women a similar trend was noted but with no statistical significance between HT and HI groups. The odd ratio for heat intolerance for every unit increase in BSA/mass was 0.97 (95% confidence interval, 0.95-0.99). The spline model plateaued above BSA/mass of 270 cm 2 ·kg -1 ., Conclusions: The results imply that body-core temperature responses to a standard exercise-heat stress (fixed external work rate and climatic conditions) are influenced by BSA/mass. More specifically, lack of a steady state in T re (indicating heat intolerance) was more likely to occur with every unit decrease in BSA/mass. These findings contribute to a better understanding of the role of body anthropometry in the response to a standard exercise-heat task that might have an implication on clinical decision making about return to duty/play of soldiers, athletes, and others who deemed to be identified as HI., (Copyright © 2024 by the American College of Sports Medicine.)