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Purpose: To investigate performance-determining variables of an on-snow sprint cross-country skiing competition and the evolvement in their relationship with performance as the competition progresses from the individual time trial (TT) to the final. Methods: Sixteen national-level male junior skiers (mean [SD] age, 18.6 [0.8] y; peak oxygen uptake [VO2peak], 67.6 [5.5] mL·min−1·kg−1) performed a simulated sprint competition (1.3 km) in the skating style, comprising a TT followed by 3 finals (quarterfinals, semifinals, and final) completed by all skiers. In addition, submaximal and incremental roller-ski treadmill tests, on-snow maximal speed tests, and strength/power tests were performed. Results: VO2peak and peak treadmill speed during incremental testing and relative heart rate, rating of perceived exertion, blood lactate concentrations, and gross efficiency during submaximal testing were all significantly correlated with performance in the TT and subsequent finals (mean [range] r values:.67 [.53–.86], all P <.05). Relative VO2peak and submaximal relative heart rate and blood lactate concentration were more strongly correlated with performance in the semifinals and final compared with the TT (r values:.74 [.60–.83] vs 0.55 [.51–.60], all P <.05). Maximal speed in uphill and flat terrain was significantly correlated with performance in the TT and subsequent finals (r values:.63 [.38–.70], all P <.05), while strength/power tests did not correlate significantly with sprint performance. Conclusions: VO2peak and high-speed abilities were the most important determinants of sprint cross-country skiing performance, with an increased importance of VO2peak as the competition format progressed toward the final. [ABSTRACT FROM AUTHOR]

Purpose: Cardiopulmonary exercise testing (CPET) is considered the gold standard for assessing cardiorespiratory fitness. To ensure consistent performance of each test, it is necessary to adapt the power increase of the test protocol to the physical characteristics of each individual. This study aimed to use machine learning models to determine individualized ramp protocols based on non-exercise features. We hypothesized that machine learning models will predict peak oxygen uptake ( V ˙ O2peak) and peak power output (PPO) more accurately than conventional multiple linear regression (MLR). Methods: The cross-sectional study was conducted with 274 (♀168, ♂106) participants who performed CPET on a cycle ergometer. Machine learning models and multiple linear regression were used to predict V ˙ O2peak and PPO using non-exercise features. The accuracy of the models was compared using criteria such as root mean square error (RMSE). Shapley additive explanation (SHAP) was applied to determine the feature importance. Results: The most accurate machine learning model was the random forest (RMSE: 6.52 ml/kg/min [95% CI 5.21–8.17]) for V ˙ O2peak prediction and the gradient boosting regression (RMSE: 43watts [95% CI 35–52]) for PPO prediction. Compared to the MLR, the machine learning models reduced the RMSE by up to 28% and 22% for prediction of V ˙ O2peak and PPO, respectively. Furthermore, SHAP ranked body composition data such as skeletal muscle mass and extracellular water as the most impactful features. Conclusion: Machine learning models predict V ˙ O2peak and PPO more accurately than MLR and can be used to individualize CPET protocols. Features that provide information about the participant's body composition contribute most to the improvement of these predictions. Trial registration number: DRKS00031401 (6 March 2023, retrospectively registered). [ABSTRACT FROM AUTHOR]

Several conditioning indicators are necessary when performing running events, such as: the ability to sustain speed during a test and obtain good competitive rates in medium and long distance events. Purpose: This systematic review was to verify the distribution of weekly training volume during the preparatory phase of recreational runners and analyse the effect of this volume on maximum oxygen consumption and time-trial running. Results: The seven studies included analysed the training volume effect. A total of 120 adult participants were included with age of 27.80 ± 5.52 years, VO2 of 47.45 ± 7.82 ml/kg/min-1 . All presented different aerobic training methods: HIIT, undulatory training, Linear, Reverse and Sprints. The interventions had an average duration of 10.00 ± 3.57 weeks. Training volume at the beginning of the interventions of 30 ± 7.21 km/week. A total of 59 adult participants with experience in road running and with performance in the 10 km and 1 km distances of 44.22 ± 8.43 min and 5.17 ± 0.24 min. Conclusion: The present review indicates that adjustments in training volume, specifically increments of up to 42% during the preparatory phase, can produce significant improvements in VO2max and time trial performance. [ABSTRACT FROM AUTHOR]

Aims Heart failure (HF) has a major impact on exercise tolerance that may (in part) be due to abnormalities in body and skeletal muscle composition. This systematic review and meta-analysis aims to assess how differences in whole-body and skeletal muscle composition between patients with HF and non-HF controls (CON) contribute to reduced peak oxygen uptake (VO2peak). Methods and results The PubMed database was searched from 1975 to May 2024 for eligible studies. Cross-sectional studies with measures of VO2peak, body composition, or muscle biopsies in HF and CON were considered. Out of 709 articles, 27 studies were included in this analysis. Compared with CON, VO2peak [weighted mean difference (WMD): −9.96 mL/kg/min, 95% confidence interval (CI): −11.71 to −8.21), total body lean mass (WMD: −1.63 kg, 95% CI: −3.05 to −0.21), leg lean mass (WMD: −1.38 kg, 95% CI: −2.18 to −0.59), thigh skeletal muscle area (WMD: −10.88 cm2 , 95% CI: −21.40 to −0.37), Type I fibres (WMD: −7.76%, 95% CI: −14.81 to −0.71), and capillary-to-fibre ratio (WMD: −0.27, 95% CI: −0.50 to −0.03) were significantly lower in HF. Total body fat mass (WMD: 3.34 kg, 95% CI: 0.35–6.34), leg fat mass (WMD: 1.37 kg, 95% CI: 0.37–2.37), and Type IIx fibres (WMD: 7.72%, 95% CI: 1.52–13.91) were significantly higher in HF compared with CON. Absolute VO2peak was significantly associated with total body and leg lean mass, thigh skeletal muscle area, and capillary-to-fibre ratio. Conclusion Individuals with HF display abnormalities in body and skeletal muscle composition including reduced lean mass, oxidative Type I fibres, and capillary-to-fibre ratio that negatively impact VO2peak. [ABSTRACT FROM AUTHOR]

Abstract Background The effects of post‐coronavirus disease 2019 (COVID‐19) syndrome on the cardiorespiratory and muscular fitness in older people are of utmost relevance. This study aimed to evaluate the effects of a 12‐week telerehabilitation programme on cardiorespiratory and muscular fitness and body composition in older patients with post‐COVID‐19 syndrome. Methods One hundred twenty older patients with post‐COVID‐19 syndrome were randomly assigned to one of two groups: patients who carried out the telerehabilitation programme (n = 60; age: 65.0 ± 5.2; female: 14.2%) and a control group (n = 60; age: 64.3 ± 5.0; female: 24.5%). An incremental cardiopulmonary exercise testing, isokinetic strength test, and bioelectrical impedance analysis were performed to compare cardiorespiratory and muscle strength responses and body composition between telerehabilitation and control groups. Results A significant increase in the cardiopulmonary exercise testing duration was found in the telerehabilitation group compared to the control group (mean difference = 88.9 s, P = 0.001). Peak oxygen uptake increased in the telerehabilitation group (mean difference = 3.0 mL·kg−1·min−1, P

The effects of face immersion and concurrent exercise on the diving reflex evoked by breath-hold (BH) differ, yet little is known about the combined effects of different BH conditions on aerobic fitness in elite athletes. This study aimed to assess the acute effects of various BH conditions on 18 male elite rugby players (age: 23.5 ± 1.8 years; height: 183.3 ± 3.4 cm; body mass: 84.8 ± 8.5 kg) and identify the BH condition eliciting the greatest aerobic fitness activation. Participants underwent five warm-up conditions: baseline regular breathing, dynamic dry BH (DD), static dry BH (SD), wet dynamic BH (WD), and wet static BH (WS). Significant differences (p < 0.05) were found in red blood cells (RBCs), red blood cell volume (RGB), and hematocrit (HCT) pre- and post-warm-up. Peak oxygen uptake (VO2peak) and relative oxygen uptake (VO2/kgpeak) varied significantly across conditions, with BH groups showing notably higher values than the regular breathing group (p < 0.05). Interaction effects of facial immersion and movement conditions were significant for VO2peak, VO2/kgpeak, and the cardiopulmonary optimal point (p < 0.05). Specifically, VO2peak and peak stroke volume (SVpeak) were significantly higher in the DD group compared to that in other conditions. Increases in VO2peak were strongly correlated with changes in RBCs and HCT induced by DD warm-up (r∆RBC = 0.84, r∆HCT = 0.77, p < 0.01). In conclusion, DD BH warm-up appears to optimize subsequent aerobic performance in elite athletes. [ABSTRACT FROM AUTHOR]

BackgroundThe benefits of exercise for primary and secondary prevention of cardiovascular events have been reported in patients with type 2 diabetes mellitus (T2DM). However, the effects of exercise on cardiac structure and function require clarification.MethodsA literature search for clinical studies reporting on the effects of exercise on cardiac structure, cardiac function, and VO2peak in T2DM patients was conducted. PubMed, Embase, EBSCO, Web of Science, and China National Knowledge Infrastructure were systematically searched for original articles published from January 2000 to July 2023. The effect size was expressed as the mean difference (MD) or standardized mean difference (SMD) and its 95% confidence interval (CI). Subgroup analyses were performed by exercise mode (high-intensity interval training [HIIT] or moderate-intensity continuous training [MICT]) and intervention duration (>6 or ≤6 months).ResultsCompared to usual care, both HIIT and MICT significantly affected left ventricular end-diastolic volume (MD: 19.44, 95% CI: 13.72 to 25.17, p < 0.00001; I2 = 42%; MD: 13.90, 95% CI: 7.64 to 20.16, p < 0.0001; I2 = 0%), but only HIIT significantly affected left ventricular mass (MD: 17.04 g, 95% CI: 5.45 to 28.62, p = 0.004; I2 = 0%). HIIT significantly improved left ventricular ejection fraction (MD: 5.52, 95% CI: 2.31 to 8.73, p = 0.0008; I2 = 0%), as did MICT in the ≤6 months subgroup (MD: 1.36, 95% CI: 0.61 to 2.10, p = 0.0004; I2 = 0%). Neither significantly affected systolic tissue velocity. HIIT significantly improved VO2peak (MD: 8.04, 95% CI: 6.26 to 9.83, p < 0.00001; I2 = 0%), as did MICT in the ≤6 months subgroup (MD: 3.33, 95% CI: 2.39 to 4.27, p < 0.00001; I2 = 0%).ConclusionExercise significantly improved cardiac structure, systolic function, and VO2peak, but did not significantly affect diastolic function in T2DM patients. HIIT seemed to be superior to MICT at improving VO2peak and left ventricular ejection fraction in T2DM patients.Systematic Review Registration:https://www.crd.york.ac.uk/PROSPERO/, PROSPERO registration no.: CRD4242018087376

This study aimed to investigate the variables determining performance in a simulated on-snow Skimo sprint competition, and how their relationship with performance evolves from the individual time trial to the final. Fifteen national-level junior Skimo athletes (mean ± SD: age, 17.8 ± 2.5 years; maximal oxygen uptake, 66.8 mL·kg−1·min−1) underwent a comprehensive assessment, involving submaximal and maximal endurance tests, maximal strength assessments, and a maximal sprint to determine maximal glycolytic capacity. Subsequently, a simulated sprint competition, comprising an individual time-trial and three heats (quarterfinal, semifinal, final), was conducted. Whole-body and upper body aerobic power (r = 0.69–0.93), maximal speed and power (r = 0.82–0.85) during the maximal performance test, as well as fat-free mass (r = 0.62–0.77) and body fat (r = −0.67–−0.77), exhibited significant correlations with performance in the time-trial, quarterfinal and semifinal. Moreover, maximal strength (r = 0.39–0.95) and transition duration (r = 0.52–0.85) showed moderate to large correlations with sprint performance. Overall, aerobic power, maximal speed and power, as well as fat-free mass, and body fat emerged as crucial determinants of Skimo sprint performance, while dynamic strength and the ability to transition quickly between sections also proved to be relevant factors. [ABSTRACT FROM AUTHOR]

Rationale: Cardiopulmonary exercise testing (CPET) provides prognostic information in cystic fibrosis (CF); however, its prognostic value for patients with advanced CF lung disease is unknown. Objectives: To determine the prognostic value of CPET on the risk of death or lung transplant (LTX) within 2 years. Methods: We retrospectively collected data from 20 CF centers in Asia, Australia, Europe, and North America on patients with a forced expiratory volume in 1 second (FEV1) ⩽ 40% predicted who performed a cycle ergometer CPET between January 2008 and December 2017. Time to death/LTX was analyzed using mixed Cox proportional hazards regression. Conditional inference trees were modeled to identify subgroups with increased risk of death/LTX. Results: In total, 174 patients (FEV1, 30.9% ± 5.8% predicted) were included. Forty-four patients (25.5%) died or underwent LTX. Cox regression analysis adjusted for age, sex, and FEV1 revealed percentage predicted peak oxygen uptake ( V ˙ o2peak) and peak work rate (Wpeak) as significant predictors of death/LTX: adjusted hazard ratios per each additional 10% predicted were 0.60 (95% confidence interval, 0.43–0.90; P = 0.008) and 0.60 (0.48–0.82; P < 0.001). Tree-structured regression models, including a set of 11 prognostic factors for survival, identified Wpeak to be most strongly associated with 2-year risk of death/LTX. Probability of death/LTX was 45.2% for those with a Wpeak ⩽ 49.2% predicted versus 10.9% for those with a Wpeak > 49.2% predicted (P < 0.001). Conclusions: CPET provides prognostic information in advanced CF lung disease, and Wpeak appears to be a promising marker for LTX referral and candidate selection. [ABSTRACT FROM AUTHOR]

Objective: This meta-analysis aims to explore the dose–response relationship of aerobic exercise or aerobic combined resistance exercise on cardiopulmonary function in maintenance hemodialysis（MHD）, with the goal of aiding in the formulation of precise exercise prescriptions. Methods: A literature search up to August 18, 2023, was conducted in databases including Web of Science, among others, focusing on the effects of exercise interventions on cardiopulmonary function in hemodialysis patients.Two researchers independently conducted literature screening, data extraction, and an assessment of study methodology quality. A dose–response meta-analysis was carried out using a one-stage cubic spline mixed-effects model, followed by stratified analyses based on intervention period, intervention method, and exercise environment. Results: A nonlinear dose–response relationship was observed between exercise and 6-minute walk test (6WMT) as well as peak oxygen uptake (VO2Peak) in hemodialysis patients. The optimal exercise dose for the 6WMT across the full exposure range was 922 METs-min/week, with VO2Peak increasing with the dose. The effects were influenced by the type of exercise, intervention period, and exercise environment. An exercise dose of 500 METs-min/week and 619 METs-min/week was found sufficient to achieve the minimal clinically important differences (MCID) for 6WMT and VO2Peak, respectively. Conclusion: There is a significant association between the dose of exercise and its effects. With appropriate adjustment of variables, even low-dose exercise can lead to clinically significant improvements in cardiopulmonary function.

Background: Time constraints comprise one limiting factor for implementing school-based physical activity programs. The aim of this pilot cluster randomized controlled study was to explore the effects of a cycle ergometer intervention during regular lessons on physical fitness, body composition, and health-related blood parameters. Methods: Participants attended one of 2 classes selected from one school, which were randomly assigned to an intervention group (n = 23, 11.2 [0.5] y) consisting of cycling on classroom-based ergometers during 3 lessons per week at a self-selected intensity and a control group (n = 21, 11.3 [0.5] y) not receiving any treatment. Prior to and after the 5-month intervention period, physical fitness (with ventilatory threshold as primary outcome), body composition, and parameters of glucose and lipid metabolism were assessed. Results: A significant time × group interaction was revealed for ventilatory threshold (P =.035), respiratory compensation point (P =.038), gross efficiency (P <.001), maximal aerobic power (P =.024), triglycerides (P =.041), and blood glucose levels (P =.041) with benefits for the intervention group. Peak oxygen uptake and body composition were not affected. Conclusions: Children's aerobic capacity benefited from the low-intensity school-based cycling intervention, while body composition and most blood parameters were not affected. The intervention using cycle ergometers is a feasible and time-saving strategy to elevate submaximal physical fitness. [ABSTRACT FROM AUTHOR]

Abstract Purpose The FitMáx© was developed as a questionnaire-based instrument to estimate Cardiorespiratory Fitness (CRF) expressed as oxygen uptake at peak exercise (VO2peak). Test–retest reliability is a clinometric measurement property, which defines stability over time if multiple measurements are performed (i.e. reliability). The present study aimed to assess the test–retest reliability of the FitMáx©-questionnaire in different patient groups. Patients and methods A total of 127 cardiac, pulmonary and oncology patients and healthy subjects aged 19–84 years who completed the questionnaire twice within an average of 18 days were included for analysis. Participants were in a stable clinical situation (no acute disease or participating in a training program). To determine the test–retest reliability, the Intraclass Correlation Coefficient (ICC) and Standard Error of the Measurement (SEM) was calculated between the first (T0) and second (T1) administration of the questionnaires. Results An excellent agreement was found between the FitMáx©-questionnaire scores at T0 and T1, with an ICC of 0.97 (SEM 1.91) in the total study population and an ICC ranging from 0.93 to 0.98 (SEM 1.52–2.27) in the individual patient groups. Conclusion The FitMáx©-questionnaire proves to be reliable and stable over time to estimate CRF of patients and healthy subjects. Trial registration NTR (Netherlands Trial Register), NL8846. Registered 25 August 2020, https://trialsearch.who.int/Trial2.aspx?TrialID=NL8846

Objective: To evaluate the exercise capacity in patients following Fontan–Kreutzer, Fontan–Björk, and total cavopulmonary connection (TCPC). Methods: Patients who performed exercise capacity tests at least once after the Fontan procedure between 1979 and 2007 were included. Patients after Fontan–Björk procedure were divided into 2 groups according to the pulmonary blood flow (PBF) pattern: patients with pulsatile PBF and those without. Peak oxygen uptake (VO2) was measured and percent-predicted VO2 was calculated. Results: A total of 227 patients were nominated. The types of Fontan procedure included Fontan–Kreutzer in 48 (21.1%) patients, Fontan–Björk in 38 (16.7%); 11 (4.8%) with pulsatile PBF and 27 (11.9%) without pulsatile PBF; and TCPC in 141 (62.1%). Median age at the Fontan procedure was 4.5 years (interquartile range, 2.1-8.2 years). A total of 978 cardiopulmonary exercise tests were performed at median follow-up of 17.7 years (interquartile range, 11.3-23.4 years) postoperatively. Analysis using linear mixed-effects models demonstrated that percent-predicted VO2 was greater in patients with pulsatile PBF after Fontan–Björk compared with patients after other types of Fontan procedure (P

Background: Left ventricular assist device (LVAD) implantation is among the most effective treatment options for patients with severe heart failure. Although previous studies have examined the factors related to peak oxygen uptake (peak VO2), they were limited by the few patients involved and their focus on medical and physical functions. Therefore, this study comprehensively examined the factors associated with peak VO2, which is an important prognostic factor in patients with implantable LVADs. Methods: Eighty‐nine patients who underwent initial LVAD implantation and were eligible for cardiopulmonary exercise testing (CPX) between May 2014 and September 2021 were included. The patients' mean age was 48 ± 12 years, and 70% were males. Based on previous studies, the cut‐off was set at 12 and 14 mL/kg/min for patients taking β‐blocker and those not taking β‐blockers, respectively. Furthermore, factors associated with peak VO2 were examined using multivariate logistic regression analysis. Results: The mean time from surgery to CPX administration was 73 ± 40 days. The high group had a higher cardiac index, right ventricular stroke work index (RVSWI), and isometric knee extensor muscular strength and lower Patient Health Questionnaire‐9 (PHQ‐9) and B‐type natriuretic peptide values than the low group. Multivariate logistic regression analysis showed that RVSWI and KEMS were positively correlated, whereas PHQ‐9 was negatively associated with peak VO2. Conclusion: Right ventricular function, depressive symptoms, and lower limb muscular strength were associated with exercise capacity in patients with implantable LVADs. [ABSTRACT FROM AUTHOR]

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DNA methylation‐based age estimators (DNAm ageing clocks) are currently one of the most promising biomarkers for predicting biological age. However, the relationships between cardiorespiratory fitness (CRF), measured directly by expiratory gas analysis, and DNAm ageing clocks are largely unknown. We investigated the relationships between CRF and the age‐adjusted value from the residuals of the regression of DNAm ageing clock to chronological age (DNAmAgeAcceleration: DNAmAgeAccel) and attempted to determine the relative contribution of CRF to DNAmAgeAccel in the presence of other lifestyle factors. DNA samples from 144 Japanese men aged 65–72 years were used to appraise first‐ (i.e., DNAmHorvath and DNAmHannum) and second‐ (i.e., DNAmPhenoAge, DNAmGrimAge, and DNAmFitAge) generation DNAm ageing clocks. Various surveys and measurements were conducted, including physical fitness, body composition, blood biochemical parameters, nutrient intake, smoking, alcohol consumption, disease status, sleep status, and chronotype. Both oxygen uptake at ventilatory threshold (VO2/kg at VT) and peak oxygen uptake (VO2/kg at Peak) showed a significant negative correlation with GrimAgeAccel, even after adjustments for chronological age and smoking and drinking status. Notably, VO2/kg at VT and VO2/kg at Peak above the reference value were also associated with delayed GrimAgeAccel. Multiple regression analysis showed that calf circumference, serum triglyceride, carbohydrate intake, and smoking status, rather than CRF, contributed more to GrimAgeAccel and FitAgeAccel. In conclusion, although the contribution of CRF to GrimAgeAccel and FitAgeAccel is relatively low compared to lifestyle‐related factors such as smoking, the results suggest that the maintenance of CRF is associated with delayed biological ageing in older men. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to investigate the association of effort-independent variables derived from the preoperative cardiopulmonary exercise test (CPET) with 30-day postoperative complications after elective colorectal surgery. Methods: A multicenter (n=4) retrospective explorative study was performed using data of patients who completed a preoperative CPET and underwent elective colorectal surgery. The preoperative slope of the relation between minute ventilation and carbon dioxide production (VE/VCO2-slope) and the oxygen uptake efficiency slope (OUES), as well as 30-day postoperative complications, were assessed. Multivariable logistic regression analyses and receiver operating characteristic (ROC) curves were used to investigate the prognostic value of the relationship between these preoperative CPET-derived effort-independent variables and postoperative complications. Results: Data from 102 patients (60.1% males) with a median age of 72.0 (interquartile range 67.8–77.4) years were analyzed. Forty-four patients (43.1%) had one or more postoperative complications (of which 52.3% general and 77.3% surgical complications). Merely 10 (9.8%) patients had a general complication only. In multivariate analysis adjusted for surgical approach (open versus minimally invasive surgery), the VE/VCO2-slope (odds ratio (OR) 1.08, confidence interval (CI) 1.02–1.16) and OUES (OR 0.94, CI 0.89–1.00) were statistically significant associated with the occurrence of 30-day postoperative complications. Conclusion: The effort-independent VE/VCO2-slope and OUES might be used to assist in future preoperative risk assessment and could especially be of added value in patients who are unable or unwilling to deliver a maximal cardiorespiratory effort. Future research should reveal the predictive value of these variables individually and/or in combination with other prognostic (CPET-derived) variables for postoperative complications. Trial registration number: ClinicalTrials.gov NCT05331196 [ABSTRACT FROM AUTHOR]

High cardiorespiratory fitness levels achieved through regular aerobic exercise are associated with reduced cardiometabolic risk. The exercise-induced myokine irisin possibly mediates these associations, but these relationships are unclear. This study aimed to clarify the relationships between circulating irisin levels, cardiorespiratory fitness levels, and cardiometabolic risk factors adjusted for sex and age. This cross-sectional study included 328 Japanese participants aged between 18 and 88 yr. We measured serum irisin levels and peak oxygen uptake (V O2peak) as cardiorespiratory fitness indicators, and body fat percentage, blood pressure, fasting blood glucose, hemoglobin A1c (HbA1c), high-density lipoprotein (HDL) cholesterol, and triglycerides as cardiometabolic risk factors. Cardiometabolic risk scores were calculated from the z-scores of the cardiometabolic risk factors. Quintiles based on V O2peak or irisin values, categorized by sex, showed a gradual increase in HDL cholesterol and a gradual decrease in other cardiometabolic risk factors with an increase in cardiorespiratory fitness levels or irisin. Serum irisin levels were negatively correlated with body fat percentage, blood pressure, fasting blood glucose, HbA1c, triglyceride levels, and cardiometabolic risk score and positively correlated with HDL cholesterol levels and V O2peak in both sexes and young, and middleaged and older adults. The same relationship was observed in all participants after adjusting for sex and age. These results suggest that circulating irisin levels may be involved in the association between cardiorespiratory fitness and cardiometabolic risk factors, regardless of sex and age. [ABSTRACT FROM AUTHOR]

Aims This study aimed to investigate the effectiveness of closed-loop stimulation (CLS) pacing compared with the traditional DDD mode in patients with chronotropic incompetence (CI) using bicycle-based cardiopulmonary exercise testing (CPET). Methods and results This single-centre, randomized crossover trial involved 40 patients with CI. Patients were randomized to receive either DDD-CLS or DDD mode pacing for 2 months, followed by a crossover to the alternative mode for an additional 2 months. Bicycling-based CPET was conducted at the 3- and 5-month follow-up visits to assess exercise capacity. Other cardiopulmonary exercise outcome measures and health-related quality of life (QoL) were also assessed. DDD-CLS mode pacing significantly improved exercise capacity, resulting in a peak oxygen uptake (14.8 ± 4.0 vs. 12.0 ± 3.6 mL/kg/min, P < 0.001) and oxygen uptake at the ventilatory threshold (10.0 ± 2.2 vs. 8.7 ± 1.8 mL/kg/min, P < 0.001) higher than those of the DDD mode. However, there were no significant differences in other cardiopulmonary exercise outcome measures such as ventilatory efficiency of carbon dioxide production slope, oxygen uptake efficiency slope, and end-tidal carbon dioxide between the two modes. Patients in the DDD-CLS group reported a better QoL, and 97.5% expressed a preference for the DDD-CLS mode. Conclusion DDD-CLS mode pacing demonstrated improved exercise capacity and QoL in patients with CI, highlighting its potential as an effective pacing strategy for this patient population. [ABSTRACT FROM AUTHOR]

Abstract Background The impact of real-time remote cardiac rehabilitation (CR) on health and disability-related outcomes and its correlation with physical function are unknown. We compared the effectiveness of real-time remote CR with that of hospital-based CR on physical function improvement and physical functions of improvement (Δ) to clarify the relationship between health and disability at baseline. Methods Patients with cardiovascular diseases (CVDs) were enrolled (n = 38) in this quasi-randomised controlled trial and underwent 4 weeks of hospital-based CR, followed by 12 weeks of remote or hospital-based CR based on quasi-randomised allocation. Patients were assessed at baseline and after 12 weeks of remote or hospital-based CR using the shortened version of the World Health Organization (WHO) Quality of Life scale (WHOQOL-BREF) for subjective satisfaction, WHO Disability Assessment Schedule (WHODAS2.0-J) for objective performance, and cardiopulmonary exercise test for physical function and peak oxygen uptake (peak VO2). The trends in measured variables from baseline to the post-CR stage were analysed. Results Sixteen patients (mean age, 72.2 ± 10.4 years) completed remote CR, and 15 patients (mean age, 77.3 ± 4.8 years) completed hospital-based CR. The post-CR physical function differed significantly between the groups (Δpeak VO2, 2.8 ± 3.0 versus 0.84 ± 1.8 mL·min−1·kg−1; p

This retrospective observational study aimed to examine the relationships of maximum walking speed (MWS) with peak oxygen uptake (peak VO2) and anaerobic threshold (AT) obtained by cardiopulmonary exercise testing (CPX) in patients with heart failure. The study participants were 104 consecutive men aged ≥ 20 years who had been hospitalized or had undergone outpatient care at our hospital for heart failure between February 2019 and January 2023. MWS was measured in a 5-m section with a 1-m run-up before and after the course. Multivariable analysis was used to examine the association between MWS and peak VO2 and AT by CPX. The Pearson correlation coefficient showed that MWS was positively correlated with percent-predicted peak VO2 and percent-predicted AT (r = 0.463, p < 0.001; and r = 0.485, p < 0.001, respectively). In the multiple linear regression analysis employing percent-predicted peak VO2 and percent-predicted AT as the objective variables, only MWS demonstrated a significant positive correlation (standardized β: 0.471, p < 0.001 and 0.362, p < 0.001, respectively). Multiple logistic regression analyses, using an 80% cutoff in percent-predicted peak VO2 and AT, revealed that only MWS was identified as a significant factor in both cases (odds ratio [OR]: 1.239, 95% confidence interval [CI]: 1.071–1.432, p = 0.004 and OR: 1.469, 95% CI: 1.194–1.807, p < 0.001, respectively). MWS was correlated with peak VO2 and AT in male patients with heart failure. The MWS measurement as a screening test for exercise tolerance may provide a simple means of estimating peak VO2 and AT in heart failure patients. [ABSTRACT FROM AUTHOR]

Purpose: To compare physiological responses between a self-paced 4-min double-poling (DP) time-trial (TTDP) versus a 4-min diagonal-stride (DS) time-trial (TTDS). The relative importance of peak oxygen uptake ( V ˙ O2peak), anaerobic capacity, and gross efficiency (GE) for projection of 4-min TTDP and TTDS roller-skiing performances were also examined. Methods: Sixteen highly trained male cross-country skiers performed, in each sub-technique on separate occasions, an 8 × 4-min incremental submaximal protocol, to assess individual metabolic rate (MR) versus power output (PO) relationships, followed by a 10-min passive break and then the TTDP or TTDS, with a randomized order between sub-techniques. Results: In comparison to TTDS, the TTDP resulted in 10 ± 7% lower total MR, 5 ± 4% lower aerobic MR, 30 ± 37% lower anaerobic MR, and 4.7 ± 1.2 percentage points lower GE, which resulted in a 32 ± 4% lower PO (all P < 0.01). The V ˙ O2peak and anaerobic capacity were 4 ± 4% and 30 ± 37% lower, respectively, in DP than DS (both P < 0.01). The PO for the two time-trial (TT) performances were not significantly correlated (R2 = 0.044). Similar parabolic pacing strategies were used during both TTs. Multivariate data analysis projected TT performance using V ˙ O2peak, anaerobic capacity, and GE (TTDP, R2 = 0.974; TTDS, R2 = 0.848). The variable influence on projection values for V ˙ O2peak, anaerobic capacity, and GE were for TTDP, 1.12 ± 0.60, 1.01 ± 0.72, and 0.83 ± 0.38, respectively, and TTDS, 1.22 ± 0.35, 0.93 ± 0.44, and 0.75 ± 0.19, respectively. Conclusions: The results show that a cross-country skier's "metabolic profile" and performance capability are highly sub-technique specific and that 4-min TT performance is differentiated by physiological factors, such as V ˙ O2peak, anaerobic capacity, and GE. [ABSTRACT FROM AUTHOR]

Data on the evolution of exercise capacity in adults with repaired coarctation of the aorta (CoA) are scarce. We aimed to investigate the evolution and change of measures of exercise capacity obtained by cardiopulmonary exercise testing (CPET) in adults with repaired CoA. Patients 16 years of age and older with CoA, who performed at least two maximal CPETs in our institution, were included in the study. The first and last available tests were used for comparative statistical analysis of common exercise variables. Sixty patients (43 men) performed serial maximal CPET. Mean age at first assessment was 30 ± 10 years (range 17–68). Mean time between first and last assessment was 3.5 years (range 1–7). Mean peak VO2 was 85.6 ± 20.4% of the predicted value at the initial test, and 87.0 ± 20.5% at the final test (p = 0.294). There were no significant differences in the mean values of oxygen pulse, VO2 at anaerobic threshold, systolic and diastolic blood pressures and peak heart rate between the two assessments. There was a slightly higher VE/VCO2 slope at the final test (p = 0.047). Higher age and Borg scale were found to be related with a decline in percent-predicted peak VO2 from initial to final assessment. In adults with repaired CoA, we found no significant change in peak VO2 during a mean follow-up of 3.5 years, yet a small increase in VE/VCO2 slope was observed. Higher age was predictive for a decline in percent-predicted peak VO2, starting in the third decade of life. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the effect of a double-poling (DP) high-intensity aerobic interval-training (HIT) intervention performed without increasing total HIT volume. This means that regular HIT training (eg, running) was replaced by HIT DP. The aim was to explore whether this intervention could improve peak oxygen uptake in DP, the fractional utilization of maximal oxygen uptake (VO2max) in DP, oxygen cost of DP, maximal aerobic speed, and a 3-km DP time trial. Methods: Nine non-specially-DP-trained cross-country skiers (intervention group) and 9 national-level cross-country skiers (control group) were recruited. All participants were tested for VO2max in running, peak oxygen uptake in DP, oxygen cost of DP, and time-trial performance before and after a 6-wk, 3-times-per-week HIT DP intervention. The intervention group omitted all regular HIT with HIT in DP, leaving the total weekly amount of HIT unchanged. Results: Seven participants in each group completed the study. VO2max in running remained unchanged in both groups, whereas peak oxygen uptake in DP improved by 7.1% (P =.005) in the intervention group. The fractional utilization of VO2max in DP thus increased by 7.3% (P =.019), oxygen cost of DP by 9.2% (P =.047), maximal aerobic speed by 16.5% (P =.009), and time trial by 19.5% (P =.004) in the intervention group but remained unchanged in the control group. Conclusions: The results indicate that a 6-wk HIT DP intervention could be an effective model to improve DP-specific capacities, with maintenance of VO2max in running. [ABSTRACT FROM AUTHOR]

Abstract Background Type 2 diabetes mellitus (T2DM) is a frequently observed complication in patients with heart failure with preserved ejection fraction (HFpEF). Although a characteristic finding in such patients is a decrease in objective exercise capacity represented by peak oxygen uptake (peakVO2), exercise capacity and its predictors in HFpEF with T2DM remain not clearly understood. This case–control study aimed to investigate the association between exercise capacity and hemodynamics indicators and T2DM comorbidity in patients with HFpEF aged 65–80 years. Methods Ninety-nine stable outpatients with HFpEF and 50 age-and-sex-matched controls were enrolled. Patients with HFpEF were classified as HFpEF with T2DM (n = 51, median age, 76 years) or without T2DM (n = 48, median age, 76 years). The peakVO2 and ventilatory equivalent versus carbon dioxide output slope (VE vs VCO2 slope) were measured by cardiopulmonary exercise testing. The peak heart rate (HR) and peak stroke volume index (SI) were measured using impedance cardiography, and the estimated arteriovenous oxygen difference (peak a-vO2 diff) was calculated with Fick's equation. The obtained data were compared among the three groups using analysis of covariance adjusted for the β-blocker medication, presence or absence of sarcopenia, and hemoglobin levels in order to determine the T2DM effects on exercise capacity and hemodynamics in patients with HFpEF. Results In HFpEF with T2DM compared with HFpEF without T2DM and the controls, the prevalence of sarcopenia, chronotropic incompetence, and anemia were significantly higher (p

Background/Objectives: A weekly combination of a high volume of moderate-intensity continuous training (MICT) with a low volume of high-intensity interval training (HIIT) provides important improvements in body composition and physical capacities in individuals with obesity. However, previous studies did not determine the weekly proportions of HIIT and MICT a priori. This study aimed to investigate changes in body composition, physical capacities and the fat oxidation rate in obese male adults by comparing a combination of MICT and HIIT, called combined training (COMB), with HIIT for a 12-week period. Methods: Thirty-four obese male adults (mean age: 39.4 ± 7.0 y; mean body mass index [BMI] 34.0 ± 4.2 kg·m−2) participated in this study (n = 18 for COMB, n = 16 HIIT), attending ∼ 36 training sessions. The COMB group performed 3 repetitions of 2 min at 95% of peak oxygen uptake (V’O2 peak) (e.g., HIIT ≤20%), followed by 30 min at 60% of VO2 peak (e.g., MICT ≥80%). The HIIT group performed 5–7 repetitions of 2 min at 95% of VO2 peak. At baseline (PRE) and at the end of the training period (POST), body composition, VO2 peak, and the fat oxidation rate were measured. The two training programs were equivalent in caloric expenditure. Results: At POST, body mass (BM) and fat mass (FM) decreased by a mean of 3.09 ± 3.21 kg and 3.90 ± 2.40 kg, respectively (P

IntroductionExercise training is an established intervention method for improving exercise capacity and survival rates in patients with heart failure with preserved ejection fraction (HFpEF). However, most reports have focused on European and American patients, with limited data regarding the effects of exercise training on cardiac function, hemodynamics, and exercise capacity in East Asian patients. This study investigated the effects of exercise training on cardiac function, hemodynamics, and exercise capacity in Japanese patients aged 65–80 years with HFpEF.MethodsThis single-center, open-label, non-randomized, controlled trial prospectively enrolled 99 outpatients. Eligibility criteria for HFpEF patients were an HFA score ≥5 in addition to clinical symptoms of heart failure and left ventricular diastolic dysfunction. Exercise training in the intervention group consisted of aerobic exercise and strength training thrice weekly for 5 months. Patients in the control group continued the usual treatment for 5 months. Resting cardiac function was evaluated using echocardiography. Peak oxygen uptake (peakVO2), ventilatory equivalent (VE) vs. carbon dioxide output (VCO2) slope, peak cardiac output index, and arteriovenous oxygen difference were calculated using cardiopulmonary exercise testing combined with impedance cardiography.ResultsAfter 5 months of exercise training, remarkable interactions were observed, with peakVO2 as the primary outcome. Additionally, significant interactions were observed between hemodynamic indices and some echocardiographic parameters. The mean percentage change in peakVO2 from baseline was 8.3% in the intervention group. Fifteen study participants (30.1%) in the intervention group achieved a clinically meaningful change of 3.0 ml/min/kg (10% improvement) in peakVO2 from baseline. The group with 3.0 ml/min/kg or 10% improvement in peakVO2 from baseline had a considerably lower prevalence of diabetes mellitus and VE vs. VCO2 slope and considerably higher left atrial-global longitudinal strain values than the group without any notable improvements.ConclusionsAlthough exercise training can help improve exercise intolerance in Japanese patients aged 65–80 years with HFpEF, its benefits are limited. Our results suggest that HFpEF, complicated by diabetes mellitus and decreased ventilatory efficiency during exercise, may require reconsideration of intervention strategies. This trial was registered with the University Hospital Medical Information Network, a trial registry in Japan (registration number: UMIN000045474).

BackgroundDespite surviving Coronavirus disease 2019 (COVID-19), its long-term impact is of concern. Low cardiorespiratory fitness is a strong predictor of all-cause mortality, and likely affected by multisystem impairments following COVID-19 infection. Accumulating evidence has identified the impact of COVID-19 on cardiorespiratory fitness level. However, the findings have been controversial. Conclusive evidence is still needed.ObjectivesThis review aimed to systematically summarize and synthesize whether the SARS-CoV-2 infection diminishes cardiorespiratory fitness in COVID-19 survivors.DesignThe study design was a systematic review and meta-analysis.MethodsA search was carried out using PubMed, CINAHL, Scopus, Embase and the Cochrane Library, together with reference lists (searching from their inception to January 2023). Observational studies investigating the impact of COVID-19 on outcomes relevant to cardiorespiratory fitness (i.e., peak oxygen uptake) were included. Weighted mean difference (WMD) and 95% confidence interval (CI) were used to identify a pooled effect estimate. Use of a random effects model was considered as the main method. Grading of Recommendation Assessment, Development and Evaluation approach was employed to determine the certainty of evidence. This meta-analysis was registered with PROSPERO (registration number: CRD42023393108).ResultsSeven eligible studies (4 cross-sectional, 2 cohort, and 1 case–control studies) involving 4,773 participants were included in this meta-analysis. A pooled effect estimates showed that patients in the surviving COVID-19 group had a significant reduction in peak oxygen uptake when compared to their counterparts in the non-COVID-19 group (WMD −6.70, 95%CI −9.34 to −4.06, low certainty). A subgroup analysis by age found that COVID-19 survivors in the young- to middle-aged and middle- to older-aged subgroups had significant reductions in peak oxygen uptake when compared to their counterparts in the non-COVID-19 group (WMD −5.31, 95%CI −7.69 to −2.94, low certainty; WMD −15.63, 95%CI −28.50 to −2.75, very low certainty, respectively). Subgroup analyses by symptom found that patients with moderate to severe symptoms in the surviving COVID-19 group had significantly lower peak oxygen uptake than their counterparts in the non-COVID-19 group (WMD −15.63, 95%CI −28.50 to −2.75, very low certainty).ConclusionThe current meta-analysis concluded that patients in the COVID-19 survivors had poorer cardiorespiratory fitness than their counterparts in the non-COVID-19 group, but there is considerable uncertainty of evidence. Poorer cardiorespiratory fitness is likely to be more pronounced in COVID-19 survivors who are getting older and had severe symptoms, but it is uncertain whether such finding has a valuable in clinical context.Systematic Review Registrationhttps://www.crd.york.ac.uk/PROSPERO/, CRD42023393108.

Summary: Background: Poor functional capacity has been identified as an important modifiable risk factor for postoperative complications. Cardiopulmonary exercise testing (CPET) provides objective parameters of functional capacity (e.g., oxygen consumption at peak exercise, peak VO2), with significant prognostication for postoperative complications. However, sex-specific thresholds for functional capacity to predict surgical risk are yet to be established. Therefore, we performed a post hoc analysis of the international, multicentre, prospective observational METS (Measurement of Exercise Tolerance before Surgery) study to evaluate if sex-specific thresholds of peak VO2 improve risk prediction of postoperative complications. Methods: We undertook a post hoc analysis (HREC/71824/PMCC) of the METS study, which was performed between March 2013 and March 2016. We investigated whether sex-specific differences exist for CPET-derived parameters and associated thresholds for predicting postoperative complications in this large cohort of patients that had major non-cardiac surgery (n = 1266). Logistic regression models were analyzed for the association of low peak VO2 with moderate-to-severe in-hospital postoperative complications. Optimal sex-specific peak VO2 thresholds were obtained by maximizing the Youden index of receiver operating characteristic (ROC) curves. Finally, multivariable logistic regression models tested the resulting sex-specific thresholds against the established non-sex-specific peak VO2 threshold (14 mL kg−1 min−1) adjusted for clinically relevant features such as comorbidities and surgical complexity. Models were evaluated by bootstrapping optimism-corrected area under the ROC curve and the net reclassification improvement index (NRI). Findings: Female patients (n = 480) had a lower mean (SD) peak VO2 than males (16.7 (4.9) mL kg−1 min−1 versus 21.2 (6.5) mL kg−1 min−1, p

Aims and Objectives: To know whether there is any exercise limitation in patients with mild COPD based on inspiratory capacity. To evaluate for forced expiratory time in mild COPD. Methods: From a period of May 2018 to April 2021, prospective observational study carried out on 30 cases of mild COPD defined by spirometry. The study was conducted in the Department of Pulmonary Medicine, Government General and Chest Hospital, Erragadda, Hyderabad, Telangana, India. Results: These 30 cases and 20 controls were evaluated for exercise limitation by exercise testing with cycle ergometer. The parameter measured is the inspiratory capacity. There is significant decrease in the inspiratory capacity in cases after the exercise test when compared to controls which was statistically significant. There in marked limitation of exercise even in cases with mild COPD. So, early intervention and proper treatment improves the quality of life and threshold for exercise. Measurement of peak oxygen uptake would have been a better parameter for exercise limitation with better outcomes. Conclusions: There in marked limitation of exercise even in cases with mild COPD. So, early intervention and proper treatment improves the quality of life and threshold for exercise. [ABSTRACT FROM AUTHOR]

Background: The impact of real-time remote cardiac rehabilitation (CR) on health and disability-related outcomes and its correlation with physical function are unknown. We compared the effectiveness of real-time remote CR with that of hospital-based CR on physical function improvement and physical functions of improvement (Δ) to clarify the relationship between health and disability at baseline. Methods: Patients with cardiovascular diseases (CVDs) were enrolled (n = 38) in this quasi-randomised controlled trial and underwent 4 weeks of hospital-based CR, followed by 12 weeks of remote or hospital-based CR based on quasi-randomised allocation. Patients were assessed at baseline and after 12 weeks of remote or hospital-based CR using the shortened version of the World Health Organization (WHO) Quality of Life scale (WHOQOL-BREF) for subjective satisfaction, WHO Disability Assessment Schedule (WHODAS2.0-J) for objective performance, and cardiopulmonary exercise test for physical function and peak oxygen uptake (peak VO2). The trends in measured variables from baseline to the post-CR stage were analysed. Results: Sixteen patients (mean age, 72.2 ± 10.4 years) completed remote CR, and 15 patients (mean age, 77.3 ± 4.8 years) completed hospital-based CR. The post-CR physical function differed significantly between the groups (Δpeak VO2, 2.8 ± 3.0 versus 0.84 ± 1.8 mL·min−1·kg−1; p < 0.05). The differences in post-CR changes in the WHOQOL-BREF scores between the groups were insignificant. The post-CR changes in the WHODAS2.0-J scores were significantly lower in the remote CR group than in the hospital-based CR group (ΔWHODAS2.0-J score, –8.56 ± 14.2 versus 2.14 ± 7.6; p < 0.01). Forward multiple stepwise regression analysis using overall data showed that the intervention method (β = 0.339, p < 0.05), baseline cognition (β = − 0.424, p < 0.05), and social interaction level (β = 0.658, p < 0.01; WHODAS2.0-J) were significant independent contributors to Δpeak VO2 (r2 = 0.48, F = 8.13, p < 0.01). Conclusions: Remote CR considerably improved physical function and objective performance in patients with CVDs. Remote CR can be used to effectively treat stable patients who cannot visit hospitals. Trial registration: This interventional trial was registered at the UMIN-CTR registry (trial title: Development of remote programme for cardiac rehabilitation using wearable electrocardiograph; trial ID: UMIN000041746; trial URL: https://center6.umin.ac.jp/cgi-open-bin/ctr%5fe/ctr%5fview.cgi?recptno=R000046564; registration date: 2020/09/09). [ABSTRACT FROM AUTHOR]

Background: Peak oxygen uptake (VO2) is often the focal point of cardiopulmonary exercise testing among patients with heart failure (HF). Breath-by-breath VO2 kinetic patterns at exercise onset, during low-level and submaximal exercise, and during recovery may provide incremental insight into HF severity and etiologies of exercise limitation. Objective: The aim of this systematic review was to explore VO2 recovery delay (VO2RD) across the spectrum of left ventricular function. Methods: A systematic review was conducted using several online databases (EMBASE, Cumulative Index to Nursing and Allied Health Literature, PubMed and Web of Science). Steps outlined by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses were followed. Search terms included VO2RD OR VO2 off kinetics AND HF, peak VO2 AND recovery. All articles were uploaded to Covidence. Results: Four studies met the inclusion criteria. The definition of VO2RD varied across studies. Recovery delay was consistently observed in HF patients compared to controls indicating VO2RD discriminates between those with and without HF. Control groups showed VO2 decline almost immediately after exercise. VO2RD had a significant positive linear relationship to N-terminal prohormone of brain natriuretic and Doppler echo E/e' while demonstrating an inverse relationship with peak cardiac output and survival duration. Conclusions: VO2RD, unlike peak VO2, is relatively cardiospecific. Oxygen recovery kinetics offer insight into disease severity and discrimination of healthy participants from those with HF.

Objective: We aimed to evaluate whether or not using the slope of the increase in minute ventilation in relation to carbon dioxide (VE/VCo2-slope), with a cutoff value of 35, could improve risk stratification for major pulmonary complications or death following lobectomy in lung cancer patients at moderate risk (Vo2peak = 10-20 mL/kg/min). Methods: Single center, retrospective analysis of 146 patients with lung cancer who underwent lobectomy and preoperative cardiopulmonary exercise testing in 2008-2020. The main outcome was any major pulmonary complication or death within 30 days of surgery. Patients were categorized based on their preoperative cardiopulmonary exercise testing as: low-risk group, peak oxygen uptake >20 mL/kg/min; low-moderate risk, peak oxygen uptake 10 to 20 mL/kg/min and VE/VCo2-slope

Purpose: Assess safety and feasibility of the cardiopulmonary exercise test (CPET) for evaluating head and neck cancer (HaNC) survivors. Also compare their cardiorespiratory fitness to age and sex‐matched norms and establish current physical activity levels. Methods: Fifty HaNC survivors [29 male; mean (SD) age, 62 (8) years], who had completed treatment up to 1 year previously, were recruited. Participants performed a CPET on a cycle ergometer to symptom‐limited tolerance. Participants completed a questionnaire to report contributory factors they perceived as influencing test termination. Physical activity levels were determined using a self‐reported physical activity questionnaire. Results: Three participants did not complete the CPET because (1) poor fitting mouthpiece and naso‐oral mask due to facial disfiguration from surgery; (2) knee pain elicited by cycling; and (3) early CPET termination due to electrocardiogram artefacts. Participants reached a mean peak oxygen uptake that was 34% lower than predicted and the mean (SD) CPET duration of 7:52 (2:29) min:s was significantly lower than the target test duration of 10 min (p < 0.001). Leg muscle aches and/or breathing discomfort were major contributory factors influencing test termination for 78% of participants, compared to 13% for dry mouth/throat and/or drainage in the mouth/throat. No major adverse events occurred. Participants were categorised as 26% active, 8% moderately active, and 66% insufficiently active. Conclusion: These preliminary data suggest the CPET appears safe and feasible for most HaNC survivors when strict exclusion criteria are applied; however, low levels of cardiorespiratory fitness should be considered when calculating an appropriate ramp rate. [ABSTRACT FROM AUTHOR]

Background: Type 2 diabetes mellitus (T2DM) is a frequently observed complication in patients with heart failure with preserved ejection fraction (HFpEF). Although a characteristic finding in such patients is a decrease in objective exercise capacity represented by peak oxygen uptake (peakVO2), exercise capacity and its predictors in HFpEF with T2DM remain not clearly understood. This case–control study aimed to investigate the association between exercise capacity and hemodynamics indicators and T2DM comorbidity in patients with HFpEF aged 65–80 years. Methods: Ninety-nine stable outpatients with HFpEF and 50 age-and-sex-matched controls were enrolled. Patients with HFpEF were classified as HFpEF with T2DM (n = 51, median age, 76 years) or without T2DM (n = 48, median age, 76 years). The peakVO2 and ventilatory equivalent versus carbon dioxide output slope (VE vs VCO2 slope) were measured by cardiopulmonary exercise testing. The peak heart rate (HR) and peak stroke volume index (SI) were measured using impedance cardiography, and the estimated arteriovenous oxygen difference (peak a-vO2 diff) was calculated with Fick's equation. The obtained data were compared among the three groups using analysis of covariance adjusted for the β-blocker medication, presence or absence of sarcopenia, and hemoglobin levels in order to determine the T2DM effects on exercise capacity and hemodynamics in patients with HFpEF. Results: In HFpEF with T2DM compared with HFpEF without T2DM and the controls, the prevalence of sarcopenia, chronotropic incompetence, and anemia were significantly higher (p < 0.001). The peakVO2 (Controls 23.5 vs. without T2DM 15.1 vs. with T2DM 11.6 mL/min/kg), peak HR (Controls 164 vs. without T2DM 132 vs. with T2DM 120 bpm/min), peak a-vO2 (Controls 13.1 vs without T2DM 10.6 vs with T2DM 8.9 mL/100 mL), and VE vs VCO2 slope (Controls 33.2 vs without T2DM 35.0 vs with T2DM 38.2) were significantly worsened in patients with HFpEF with T2DM (median, p < 0.001). There was no significant difference in peak SI among the three groups. Conclusions: Our results suggested that comorbid T2DM in patients with HFpEF may reduce exercise capacity, HR response, peripheral oxygen extraction, and ventilation efficiency. These results may help identify cardiovascular phenotypes of HFpEF complicated with T2DM and intervention targets for improving exercise intolerance. [ABSTRACT FROM AUTHOR]

A weekly combination of a high volume of moderate-intensity continuous training (MICT) with a low volume of high-intensity interval training (HIIT) provides important improvements in body composition and physical capacities in individuals with obesity. However, previous studies did not determine the weekly proportions of HIIT and MICT a priori. This study aimed to investigate changes in body composition, physical capacities and the fat oxidation rate in obese male adults by comparing a combination of MICT and HIIT, called combined training (COMB), with HIIT for a 12-week period. Thirty-four obese male adults (mean age: 39.4 ± 7.0 y; mean body mass index [BMI] 34.0 ± 4.2 kg·m−2) participated in this study (n = 18 for COMB, n = 16 HIIT), attending ∼ 36 training sessions. The COMB group performed 3 repetitions of 2 min at 95% of peak oxygen uptake (V'O 2 peak) (e.g., HIIT ≤20%), followed by 30 min at 60% of VO 2 peak (e.g., MICT ≥80%). The HIIT group performed 5–7 repetitions of 2 min at 95% of VO 2 peak. At baseline (PRE) and at the end of the training period (POST), body composition, VO 2 peak, and the fat oxidation rate were measured. The two training programs were equivalent in caloric expenditure. At POST, body mass (BM) and fat mass (FM) decreased by a mean of 3.09 ± 3.21 kg and 3.90 ± 2.40 kg, respectively (P < 0.05), in both groups and V'O 2 peak increased in both groups by a mean of 0.47 ± 0.34 L·min−1 (P < 0.05). The maximal fat oxidation rate increased similarly in both groups from 0.32 ± 0.05 to 0.36 ± 0.06 g·min−1 (P < 0.05). COMB training represents a viable alternative to HIIT to improve anthropometric characteristics, physical capacities and fat oxidation in obese male adults. [ABSTRACT FROM AUTHOR]

Exercise intolerance is a major manifestation of pulmonary arterial hypertension associated with congenital heart disease (PAH-CHD). We aimed to investigate the characteristics of exercise intolerance in different subgroups of PAH-CHD. We retrospectively enrolled 171 adult patients with PAH-CHD and 30 age and sex-matched healthy subjects and performed cardiopulmonary exercise testing. Gas exchange parameters, including peak oxygen uptake (peak V̇ o 2), anaerobic threshold, and the slope of ventilatory equivalent for carbon dioxide (V̇ e /V̇ co 2 slope), were recorded. The median age of patients at enrollment was 27.8 years, and 131 (76.6%) were female. Peak V̇ o 2 was reduced in patients compared to healthy controls (median, 14.8 ml/kg/min versus 26.9 ml/kg/min, p < 0.001). Of all 171 patients, 60 (35.1%) had Eisenmenger syndrome, 35 (20.5%) had PAH associated with systemic-to-pulmonary shunts (PAH-SP), 39 (22.8%) had PAH with small defects (PAH-SD), and 37 (21.6%) had PAH after cardiac defect correction (PAH-CD). Patients with Eisenmenger syndrome had the lowest peak V̇ o 2 (p = 0.003) and the highest V̇ e /V̇ co 2 slope (p = 0.012), compared with other patients, representing the worst exercise capacity and ventilatory efficiency. Patients with PAH-SP had the best exercise capacity among the four groups, indicated by the highest peak V̇ o 2 (p = 0.003) compared with other patients. Peak V̇ o 2 was negatively correlated with pulmonary vascular resistance (r = −0.411, p < 0.001). Exercise capacity was severely reduced in patients with PAH-CHD. Among the four subgroups, patients with Eisenmenger syndrome had the worst exercise capacity and ventilatory efficiency. • Exercise capacity was severely reduced in patients with PAH-CHD. • Among the four subgroups, patients with Eisenmenger syndrome had the worst exercise capacity and ventilatory efficiency. • Patients with PAH-SP had the best exercise capacity among the four subgroups. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the variables determining performance in a simulated on-snow Skimo sprint competition, and how their relationship with performance evolves from the individual time trial to the final. Fifteen national-level junior Skimo athletes (mean ± SD: age, 17.8 ± 2.5 years; maximal oxygen uptake, 66.8 mL·kg−1·min−1) underwent a comprehensive assessment, involving submaximal and maximal endurance tests, maximal strength assessments, and a maximal sprint to determine maximal glycolytic capacity. Subsequently, a simulated sprint competition, comprising an individual time-trial and three heats (quarterfinal, semifinal, final), was conducted. Whole-body and upper body aerobic power (r = 0.69–0.93), maximal speed and power (r = 0.82–0.85) during the maximal performance test, as well as fat-free mass (r = 0.62–0.77) and body fat (r = −0.67–−0.77), exhibited significant correlations with performance in the time-trial, quarterfinal and semifinal. Moreover, maximal strength (r = 0.39–0.95) and transition duration (r = 0.52–0.85) showed moderate to large correlations with sprint performance. Overall, aerobic power, maximal speed and power, as well as fat-free mass, and body fat emerged as crucial determinants of Skimo sprint performance, while dynamic strength and the ability to transition quickly between sections also proved to be relevant factors.

Purpose: Long-distance cross-country skiers specialize to compete in races >50 km predominantly using double poling (DP). This emphasizes the need for highly developed upper-body endurance capacities and an efficient DP technique. The aim of this study was to investigate potential effects of specialization by comparing physiological capacities and kinematics in DP between long-distance skiers and skiers competing using both techniques (skating/classic) in several competition formats ("all-round skiers"). Methods: Seven male long-distance (32 [6] y, 183 [6] cm, 76 (5] kg) and 6 all-round (25 [3] y, 181 [5] cm, 75 [6] kg) skiers at high international levels conducted submaximal workloads and an incremental test to exhaustion for determination of peak oxygen uptake (VO2peak) and time to exhaustion (TTE) in DP and running. Results: In DP and running maximal tests, TTE showed no difference between groups. However, long-distance skiers had 5-6% lower VCLpeak in running (81 [5] vs 85 [3] mL·kg-1·min-1; P = .07) and DP (73 [3] vs 78 [3] mL·kg-1·min-1; P < .01) than all-round skiers. In DP, long-distance skiers displayed lower submaximal O2 cost than all-round skiers (3.8±3.6%; P < .05) without any major differences in cycle times or cyclic patterns of joint angles and center of mass. Lactate concentration over a wide range of speeds (45-85% of VO2peak) did not differ between groups, even though each workload corresponded to a slightly higher percentage of VO2peak for long-distance skiers (effect size: 0.30-0.68). Conclusions: The long-distance skiers displayed lower VO2peak but compensated with lower O2 cost to perform equally with the all-round skiers on a short TTE test in DP. Furthermore, similar submaximal lactate concentration and reduced 0 2 cost could be beneficial in sustaining high skiing speeds in long-duration competitions. [ABSTRACT FROM AUTHOR]

In this paper, we draw on cross-sectional, treadmill-determined, peak oxygen uptake data, collected in our laboratory over a 20-year period, to examine whether traditional per body mass (ratio) scaling appropriately controls for body size differences in youth. From an examination of the work of pioneering scientists and the earliest studies of peak oxygen uptake, we show how ratio scaling appears to have no sound scientific or statistical rationale. Using simple methods based on correlation and regression, we demonstrate that the statistical relationships, which are assumed in ratio scaling, are not met in groups of similar aged young people. We also demonstrate how sample size and composition can influence relationships between body mass and peak oxygen uptake and show that mass exponents derived from log-linear regression effectively remove the effect of body mass. Indiscriminate use of ratio scaling to interpret young people's fitness, to raise "Clinical Red Flags", and to assess clinical populations concerns us greatly, as recommendations and conclusions based upon this method are likely to be spurious. We urge those involved with investigating youth fitness to reconsider how data are routinely scaled for body size. [ABSTRACT FROM AUTHOR]

Purpose: This study had 2 objectives: (1) to examine whether the validity of the supramaximal verification test for maximal oxygen uptake ( V ˙ O 2 max) differs in children and adolescents when stratified for sex, body mass, and cardiorespiratory fitness and (2) to assess sensitivity and specificity of primary and secondary objective criteria from the incremental test to verify V ˙ O 2 max. Methods: In total, 128 children and adolescents (76 male and 52 females; age: 9.3–17.4 y) performed a ramp-incremental test to exhaustion on a cycle ergometer followed by a supramaximal test to verify V ˙ O 2 max. Results: Supramaximal tests verified V ˙ O 2 max in 88% of participants. Group incremental test peak V ˙ O 2 was greater than the supramaximal test (2.27 [0.65] L·min−1 and 2.17 [0.63] L·min−1; P <.001), although both were correlated (r =.94; P <.001). No differences were found in V ˙ O 2 plateau attainment or supramaximal test verification between sex, body mass, or cardiorespiratory fitness groups (all Ps >.18). Supramaximal test time to exhaustion predicted supramaximal test V ˙ O 2 max verification (P =.04). Primary and secondary objective criteria had insufficient sensitivity (7.1%–24.1%) and specificity (50%–100%) to verify V ˙ O 2 max. Conclusion: The utility of supramaximal testing to verify V ˙ O 2 max is not affected by sex, body mass, or cardiorespiratory fitness status. Supramaximal testing should replace secondary objective criteria to verify V ˙ O 2 max. [ABSTRACT FROM AUTHOR]

Cardiopulmonary exercise testing (CPET) modalities, treadmill (TM), and cycle ergometer (CE), influence maximal gas exchange and heart rate (HR) responses. Little is known regarding CPET modality effect on submaximal biomarkers during childhood and adolescence. Ninety-four healthy participants (7-34 y.o., 53% female) performed TM and CE CPET to address two major gaps: (1) the effect of modality on submaximal CPET biomarkers, and (2) estimation of work rate in TM CPET. Breath-by-breath gas exchange enabled calculation of linear regression slopes such as V˙ O2 /ΔHR and Δ V˙ E/Δ V˙ CO2 . Lean body mass (LBM) was measured with dual X-ray absorptiometry. We tested a novel TM CPET estimate of work rate based on TM velocity2 , incline, and body mass (VIM). Like the linear relationship between V˙ O2 and work rate in CE CPET, V˙ O2 increased linearly with TM VIM. TM Δ V˙ O2 /ΔHR was highly correlated with CE (r = 0.92), and each increased substantially with LBM (P

Background Cardiopulmonary problems will increase the risk of health harms yet they are often neglected in clinical rehabilitation treatment for stroke patients. In addition, sleep problems also often affect the rehabilitation effect in these patients, while routine drug treatment could not achieve satisfactory effect. Objective To assess the effect of precisely prescribed exercise on cardiopulmonary fitness and sleep quality in stroke patients. Methods Sixty-four stroke inpatients were recruited from Rehabilitation Department, Changzhou Dean Hospital from April 2020 to August 2021, and equally randomized into a control group and an experimental group. At baseline, cardiopulmonary fitness was assessed using cardiopulmonary exercise testing (CPET) , and sleep quality was assessed using Pittsburgh Sleep Quality Index (PSQI) for both groups. Then control group received 12-week routine rehabilitation training, while experimental group received 12-week routine rehabilitation training plus aerobic exercise precisely prescribed based on baseline CPET parameters. Intra- and inter-group comparisons were made between pre- and post-training major CPET parameters, dyspnea and leg fatigue measured by the Borg Scale and sleep quality. Results At the end of training, the experimental group demonstrated higher peak oxygen uptake (VO2peak) , percentage of predicted peak oxygen uptake (VO2peak%pred) , peak metabolic equivalent (METpeak) , peak heart rate (HRpeak) , peak load, and anaerobic threshold (AT) , and lower intensity of perceived dyspnea and leg fatigue than the control group (P

ObjectiveCardiopulmonary exercise testing (CPET) is currently recommended for all patients undergoing lung resection with either respiratory comorbidities or functional limitations. The main parameter evaluated is oxygen consumption at peak (VO2peak). Patients with VO2peak above 20 ml/kg/min are classified as low risk surgical candidates. The aims of this study were to evaluate postoperative outcomes of low-risk patients, and to compare their outcomes with those of patients without pulmonary impairment at respiratory function testing.MethodsRetrospective monocentric observational study was designed, evaluating outcomes of patients undergoing lung resection at San Paolo University Hospital, Milan, Italy, between January 2016 and November 2021, preoperatively assessed by CPET, according to 2009 ERS/ESTS guidelines. All low-risk patients undergoing any extent surgical lung resection for pulmonary nodules were enrolled. Postoperative major cardiopulmonary complications or death, occurring within 30 days from surgery, were assessed. A case-control study was nested, matching 1:1 for type of surgery the cohort population with control patients without functional respiratory impairment consecutively undergoing surgery at the same centre in the study period.ResultsA total of 80 patients were enrolled: 40 subjects were preoperatively assessed by CPET and deemed at low risk, whereas 40 subjects represented the control group. Among the first, 4 patients (10%) developed major cardiopulmonary complications, and 1 patient (2.5%) died within 30 days from surgery. In the control group, 2 patients (5%) developed complications and none of the patients (0%) died. The differences in morbidity and mortality rates did not reach statistically significance. Instead, age, weight, BMI, smoking history, COPD incidence, surgical approach, FEV1, Tiffenau, DLCO and length of hospital stay resulted significantly different between the two groups. At a case-by-case analysis, CPET revealed a pathological pattern in each complicated patient, in spite of VO2peak above target for safe surgery.ConclusionsPostoperative outcomes of low-risk patients undergoing lung resections are comparable to those of patients without any pulmonary functional impairment; nonetheless the formers represent a dramatically different category of individuals from the latter and may harbour few patients with worse outcomes. CPET variables overall interpretation may add to the VO2peak in identifying higher risk patients, even in this subgroup.

Cardiorespiratory fitness is established as an important prognostic factor for cardiovascular and general health. In clinical settings cardiorespiratory fitness is often measured by cardiopulmonary exercise testing determining the gold-standard peak oxygen uptake (VO2peak). Due to the considerable impact of age and sex on VO2peak, results from cardiopulmonary exercise testing are typically assessed in the context of age- and sex-specific reference values, and multiple studies have been conducted establishing reference materials by age and sex using cross-sectional designs. However, crossectional and longitudinal studies have shown somewhat conflicting results regarding age-related declines of VO2peak, with larger declines reported in longitudinal studies. In this brief review, we compare findings from crossectional and longitudinal studies on age-related trajectories in VO2peak to highlight differences in these estimates which should be acknowledged when clinicians interpret VO2peak measurements repeated over time.

Decreased systemic oestrogen levels (i.e., menopause) affect metabolic health. However, the detailed mechanisms underlying this process remain unclear. Both oestrogens and exercise have been shown to improve metabolic health, which may be partly mediated by circulating microRNA (c‐miR) signalling. In recent years, extracellular vesicles (EV) have increased interest in the field of tissue crosstalk. However, in many studies on EV‐carried miRs, the co‐isolation of high‐density lipoprotein (HDL) particles with EVs has not been considered, potentially affecting the results. Here, we demonstrate that EV and HDL particles have distinct small RNA (sRNA) content, including both host and nonhost sRNAs. Exercise caused an acute increase in relative miR abundancy in EVs, whereas in HDL particles, it caused an increase in transfer RNA‐derived sRNA. Furthermore, we demonstrate that oestrogen‐based hormonal therapy (HT) allows the acute exercise‐induced miR‐response to occur in both EV and HDL particles in postmenopausal women, while the response was absent in nonusers. [ABSTRACT FROM AUTHOR]

• CFRD is not associated with VO 2peak in people with CF. • Physical activity is not different between people with and without CFRD. • People with impaired glucose tolerance/CFRD have comparable VO 2peak compared to those with normal glucose tolerance. Previous studies have reported differences in aerobic exercise capacity, expressed as peak oxygen uptake (VO 2peak), between people with and without cystic fibrosis (CF) related diabetes (CFRD). However, none of the studies controlled for the potential influence of physical activity on VO 2peak. We investigated associations between CFRD and VO 2peak following rigorous control for confounders including objectively measured physical activity. Baseline data from the international multicenter trial ACTIVATE-CF with participants ≥12 years performing up to 4 h per week of vigorous physical activity were used for this project. Multivariable models were computed to study associations between CFRD and VO 2peak (mL.min−1) adjusting for a set of pre-defined covariates: age, sex, weight, forced expiratory volume in 1 s (FEV 1), breathing reserve index, Pseudomonas aeruginosa infection, and physical activity (aerobic step counts from pedometry). Variables were selected based on their potential confounding effect on the association between VO 2peak and CFRD. Among 117 randomized individuals, 103 (52% female) had a maximal exercise test and were included in the analysis. Participants with (n = 19) and without (n = 84) CFRD did not differ in FEV 1 , physical activity, nutritional status, and other clinical characteristics. There were also no differences in VO 2peak (mL.min−1 or mL.kg−1.min−1 or% predicted). In the final multivariable model, all pre-defined covariates were significant predictors of VO 2peak (mL.min−1), however CFRD [coefficient 82.1, 95% CI -69.5 to 233.8, p = 0.28] was not. This study suggests no meaningful differences in VO 2peak between people with and without CFRD given comparable levels of physical activity. [ABSTRACT FROM AUTHOR]