Differences In VO2peak Research Articles

Influence of Sex and Body Composition on Aerobic Capacity in Normal Weight Lean, Normal Weight Obese, and Obese Phenotypes

Normal weight obesity (NWO) is a body composition phenotype that is associated with increased cardiometabolic risk and is characterized by a normal weight body mass index but elevated body fat. The purpose of this study was to determine sex differences in aerobic capacity across body composition phenotypes, including normal weight lean (NWL), NWO, and traditional obesity (OB). We recruited 60 participants according to three body composition phenotypes: NWL (n = 10 females, n = 10 males), NWO (n = 10 females, n = 10 males), and OB (n = 10 females, n = 10 males). Measurements included fasting metabolic risk factors, body composition X-ray scan, and peak exercise test on a cycle ergometer to determine aerobic capacity (VO2peak). Across groups, males (34.5 ± 11.7 mL/kg/min) exhibited greater VO2peak than females (28.8 ± 8.8 mL/kg/min; p = 0.04). There were no differences in VO2peak between sexes within the same body composition phenotype, but NWL (42.7 ± 9.0 mL/kg/min) exhibited greater VO2peak than NWO (27.9 ± 4.4 mL/kg/min; p < 0.0001) and OB (24.4 ± 7.3 mL/kg/min; p < 0.0001). VO2peak was inversely correlated with relative body fat in the full sample (r = −0.67; p < 0.0001), but was stronger in males (r = −0.78; p < 0.0001) than females (r = −0.53; p = 0.0028). Visceral adipose tissue was not significantly correlated with VO2peak in the full sample (r = −0.25; p = 0.05) or in males (r = −0.23; p = 0.25), although they were inversely correlated in females (r = −0.36; p = 0.048). Our results suggest low aerobic capacity in both men and women with NWO, similar to men and women with OB. The relationship between body composition and aerobic capacity is strong across body composition phenotypes, but appears to be more consistent in females than males. For healthcare professionals aiming to lower cardiometabolic risk, attention should be given to improving aerobic fitness in both men and women with elevated body fat, including those with NWO.

High-intensity interval training is an effective exercise mode to maintain normal blood pressure during pregnancy: a randomized control trial

Pregnant women are more susceptible to high blood pressure (BP) than the general adult population; therefore, all means of preventing this condition should be considered. High-intensity interval training (HIIT) is effective in this regard in the general population, but there is a lack of evidence of its effectiveness during pregnancy. This study aimed to compare an 8-week HIIT program to self-performed moderate-to-vigorous physical activity among pregnant women by evaluating changes in BP after a maximal progressive cardiorespiratory exercise test (CPET) performed at pre-intervention and post-intervention time points. A total of 54 Caucasian women in uncomplicated, singleton pregnancies (age 32 ± 4 years, 22 ± 4 weeks of gestation; M ± SD) with normal BP values completed the interventions. The experimental (HIIT) group (n = 34) completed an online supervised HIIT program consisting of three sessions per week and supplemented by an educational class once per week. Participants in the education (EDU) group (n = 20) attended an educational class once per week and were encouraged to perform moderate-to-vigorous physical activity (PA) on their own. Pre- and post-intervention, all women underwent a CPET on a cycle ergometer with a respiratory gas analyzer. On the day of the CPET, maternal systolic and diastolic BP (mmHg) was measured at rest (before the CPET) and approximately 60 min after the CPET using an electronic BP monitor. Identical CPET and BP measurement protocols were employed for both the HIIT and EDU groups at the pre- and post-intervention time points. Pre-intervention, the HIIT and EDU groups both showed a decrease in systolic and diastolic BP after the CPET, though only the change in systolic BP was statistically significant (HIIT group: p = 0.01; EDU group: p = 0.001). Post-intervention, there were no significant differences in either group between resting and post-CPET BP. There were significant post-intervention differences in VO2peak (p < 0.001) and HRmax (p = 0.002) between the HIIT and EDU groups. From pre- to post-intervention, the EDU and HIIT groups both showed decreases in resting systolic or diastolic BP; there was a significant difference in systolic BP in the EDU group (p = 0.005) and a significant difference in diastolic BP in the HIIT group (p = 0.03). Both groups maintained normal BP values throughout the experiment. However, HIIT, in addition to maintaining normotension, improved cardiorespiratory fitness in pregnant women. It seems that both supervised HIIT and self-performed moderate-to-vigorous PA can be recommended as strategies to prevent BP disorders during pregnancy. More studies are needed to confirm our findings.Trial registration The full study protocol was registered in ClinicalTrials.gov (NCT05009433).

Aerobic exercise training and obstructive sleep apnea: dose-response meta-analyses.

Several studies have shown that aerobic exercise training improves obstructive sleep apnea (OSA) severity. However, a dose-response relationship has never been shown. This study aimed to quantify any dose-response relationships between time spent per week in aerobic exercise and key sleep apnea outcomes. Randomized controlled trials (RCT) were selected from literature search studying the effects of supervised aerobic exercise training on patients with OSA. Dose-response meta-analyses were performed, where the 'dose' was the total weekly duration of aerobic exercise training. Primary outcomes were apnea hypopnea index (AHI), cardiorespiratory fitness (maximum oxygen consumption or VO2peak) and Epworth Sleepiness Scale (ESS). Analysis of data from 11 RCTs showed a non-linear dose-response relationship between the total weekly duration of aerobic exercise training and mean differences in AHI. Maximum effects on AHI (-10.92 (95%CIs: -15.57; -6.27)) were observed when the weekly duration of aerobic exercise reached 100min/week. Similar non-linear dose-response trend was observed in the mean differences in VO2peak. Studies in which aerobic exercise training lasted ≥ 12 weeks showed greater proportional changes in mean AHI differences with maximal effects reaching a peak at ∼ 70min/week of aerobic exercise training. ESS and total weekly duration of aerobic exercise training showed a linear dose-response relationship based on 4 RCTs. Based on these analyses, aerobic exercise training of 70-100min/week over 3 or 5 days a week should be recommended as adjunctive treatment for patients with OSA.

#1555 The effects of different interdialytic intervals on cardiorespiratory fitness assessed with CPET in hemodialysis patients

Abstract Background and Aims Long interdialytic interval in thrice-weekly hemodialysis is associated with excess cardiovascular and all-cause mortality risk. Impaired cardiorespiratory fitness is a strong predictor of mortality in hemodialysis. This study investigated differences in cardiorespiratory fitness assessed with cardiopulmonary exercise testing (CPET) between the end of the 2-day and the 3-day interdialytic interval. Method A total of 28 hemodialysis patients, randomized in two different sequences of evaluation underwent CPET and spirometry examination at the end of the 2-day and the 3-day intervals. The primary outcome was the difference in oxygen uptake at peak exercise [VO2peak (ml/kg/min)] assessed with CPET. Volume status was assessed with interdialytic-weight-gain (IDWG), lung ultrasound, bioimpedance spectroscopy (BIS), and inferior vena cava measurements. A total of 14 age- and sex-matched controls were also evaluated. Results Hemodialysis patients at the end of both 2-day and 3-day intervals presented lower values in all major CPET parameters than controls. VO2peak (ml/kg/min) was significantly higher at the end of the 2-day than the 3-day interval (15.24 ± 4.18 vs 13.64 ± 2.76; p &amp;lt; 0.001); similar were the results for VO2peak (ml/min) (1188 ± 257 vs 1074 ± 224; p &amp;lt; 0.001) and VO2peak (%predicted) (58.9 ± 9.2 vs 52.3 ± 8.6; p &amp;lt; 0.001). Numerical but no statistically significant differences were detected in VO2-anaerobic-threshold(ml/kg/min) and VO2-anaerobic-threshold(ml/min) between the two time-points. Maximal work load (90.1 ± 23.2 vs 79.3 ± 25.1; p &amp;lt; 0.001), exercise duration, HR at peak exercise and oxygen pulse also showed lower values at the end of the 3-day interval. FEV1 levels were similar between the two evaluations. Generalized-linear-mixed-model analysis including IDWG as random covariate attenuated the observed differences in VO2peak (ml/kg/min). Changes in BIS-derived overhydration indexes were moderately correlated with changes of VO2peak (ml/kg/min). Conclusion The 3-day interval was associated with further impairment of VO2 at peak exercise. This effect was predominantly driven by excess fluid accumulation during the extra interdialytic day.

THE EFFECTS OF DIFFERENT INTERDIALYTIC INTERVALS ON CARDIORESPIRATORY FITNESS ASSESSED WITH CARDIOPULMONARY EXERCISE TESTING IN HEMODIALYSIS PATIENTS

Objective: Long interdialytic interval in thrice-weekly hemodialysis is associated with excess cardiovascular and all-cause mortality risk. Impaired cardiorespiratory fitness is a strong predictor of mortality in hemodialysis. This study investigated differences in cardiorespiratory fitness assessed with cardiopulmonary exercise testing (CPET) between the end of the 2-day and the 3-day interdialytic interval. Design and method: A total of 28 hemodialysis patients, randomized in two different sequences of evaluation underwent CPET and spirometry examination at the end of the 2-day and the 3-day intervals. The primary outcome was the difference in oxygen uptake at peak exercise [VO2peak(ml/kg/min)] assessed with CPET. Volume status was assessed with interdialytic-weight-gain (IDWG), lung ultrasound, bioimpedance spectroscopy (BIS), and inferior vena cava measurements. A total of 14 age- and sex-matched controls were also evaluated. Results: Hemodialysis patients at the end of both 2-day and 3-day intervals presented lower values in all major CPET parameters than controls. VO2peak(ml/kg/min) was significantly higher at the end of the 2-day than the 3-day interval (15.24±4.18 vs 13.64±2.76;p&lt;0.001); similar were the results for VO2peak(ml/min) (1188±257 vs 1074±224;p&lt;0.001) and VO2peak(%predicted) (58.9±9.2 vs 52.3±8.6;p&lt;0.001). Numerical but no statistically significant differences were detected in VO2-anaerobic-threshold(ml/kg/min) and VO2-anaerobic-threshold(ml/min) between the two time-points. Maximal work load (90.1±23.2 vs 79.3±25.1;p&lt;0.001), exercise duration, HR at peak exercise and oxygen pulse also showed lower values at the end of the 3-day interval. FEV1 levels were similar between the two evaluations. Generalized-linear-mixed-model analysis including IDWG as random covariate attenuated the observed differences in VO2peak(ml/kg/min). Changes in BIS-derived overhydration indexes were moderately correlated with changes of VO2peak(ml/kg/min). Conclusions: The 3-day interval was associated with further impairment of VO2 at peak exercise. This effect was predominantly driven by excess fluid accumulation during the extra interdialytic day.

Adaptation to Living at High Altitude in Patients with COPD. Comparative Study of Exercise Capacity and Ventilatory Variables between Patients Residing at High and Low Altitudes in the Andes.

González-García, Mauricio and Luis Ernesto Téllez. Adaptation to living at high altitude in patients with COPD. Comparative study of exercise capacity and ventilatory variables between patients residing at high and low altitudes in the Andes. High Alt Med Biol. 25:266-273, 2024. Introduction: Although some variables related to oxygen transport and utilization such as ventilation, pulmonary vascular responses to hypoxia, heart rate (HR), cardiac output, hemoglobin (Hb), and oxygen saturation (SpO2) are used to compare adaptation to altitude between populations, peak oxygen consumption (VO2) constitutes an integrative measure of total oxygen transport that may reflect successful adaptation to altitude. We designed this study to make a direct comparison of VO2 in a cardiopulmonary exercise test (CPET) between chronic obstructive pulmonary disease (COPD) patients residing at high altitude (Bogotá, Colombia: 2,640 m) (COPD-HA) and those living at low altitude (Bucaramanga, Colombia: 959 m) (COPD-LA). Methods: All patients performed a CPET with measurements of VO2, minute ventilation (VE), HR, oxygen pulse (VO2/HR), ventilatory equivalents (VE/VCO2), and SpO2. Unpaired T-test or Mann-Whitney U test were used for comparisons between COPD-HA and COPD-LA. Results: We included 71 patients with COPD, 53 COPD-HA, and 18 COPD-LA. There were no differences between groups in age, sex, or forced expiratory volume in 1 second. The means ± SD of Hb, g/dl was slightly higher in COPD-HA (15.9 ± 1.9 vs. 14.7 ± 1.8, p = 0.048), without differences in VO2, % pred (71.6 ± 17.9 vs. 69.0 ± 17.0, p = 0.584), VO2/HR, % pred (92.1 ± 22.0 vs. 89.7 ± 19.8, p = 0.733) or VE/MVV, % (75.5 ± 14.1 vs. 76.5 ± 14.3, p = 0.790) at peak exercise between groups. Median (IQR) of VE/VCO2 nadir [38.0 (37.0-42.0) vs. 32.5 (31.0-39.0), p = 0.005] was significantly higher, and SpO2, % at rest [88.0 (86.0-91.0) vs. 95.0 (94.0-96.0), p < 0.001] and at peak exercise [84.0 (77.0-90.0) vs. 93.0 (92.0-95.0), p < 0.001] were significantly lower in COPD-HA. Conclusions: Despite higher desaturation at rest and during exercise in COPD-HA, there were no differences in VO2 peak between COPD-HA and COPD-LA, suggesting a potential altitude adaptation in those patients chronically exposed to hypoxia.

Effects of Different Warm-up Protocols on the Cardiopulmonary Responses to Exercise Testing in Youth

The aim of this study was to compare the warm-up effects of a treadmill walking warm-up (TW) with a dynamic warm-up (DW) on the responses to cardiopulmonary exercise testing (CPET) in youth. A sample of 16 active youth (age 13.6 ± 1.8 yr) were tested for peak oxygen uptake (VO2 peak) using the Fitkids treadmill test protocol on 2 nonconsecutive days following different 6-min warm-up procedures. The TW consisted of walking on a treadmill at 2.2 mph and 0% grade whereas the DW consisted of 12 bodyweight exercises with a 2 kg medicine ball. Maximal heart rate (HR) was significantly higher following DW vs TW (200.8 ± 6.16 vs. 197.9 ± 7.3 bpm, respectively; p &lt; 0.05), whereas no significant differences were found between DW and TW for VO2 peak (50.5 ± 9.9 vs 50.6 ± 11.1 ml/kg/min), maximal minute ventilation (VE; 93.0 ±21.4 vs. 92.7 ±21.2 L/min), maximal respiratory exchange ratio (1.19 ± 0.08 vs 1.22 ± 0.08), and total exercise test time (668.1 ± 103.5 vs 686.3 ± 97.0 s), respectively. During the Fitkids treadmill test protocol HR and VE were significantly higher following DW vs TW at stage 1, stage 2, stage 3 and stage 4, and oxygen uptake was significantly higher following DW vs TW during stage 1 (all p &lt; 0.05). Findings indicate a DW elicits a higher maximal HR and higher submaximal HR, VE, and oxygen uptake values than TW during CPET in youth, although no differences in VO2 peak were observed.

High-intensity interval training in breast cancer patients: A systematic review and meta-analysis.

Women with breast cancer and improved survival often experience treatment-related impairments. High-intensity interval training (HIIT) has emerged as a promising exercise therapy modality for adult cancer patients. However, the overall effects of HIIT in breast cancer patients remain scarce and controversial. Therefore, we conducted a systematic review and meta-analysis to comprehensively evaluate the impact of HIIT on health-related outcomes in breast cancer patients. We searched the PubMed, Embase, and Web of Science from inception to November 7, 2022. Eligible studies included randomized controlled trials that compared HIIT interventions with usual care (UC) or MICT in breast cancer patients. The primary outcome assessed was physical fitness, and exploratory outcomes included body composition, blood-borne biomarkers, and patient-reported outcomes. Summary data were extracted, and standardized mean differences (SMD) were calculated for meta-analysis. For outcomes that could not be pooled, a systematic review was conducted. Our analysis included 19 articles from 10 studies, encompassing 532 participants who met the inclusion criteria. Pooled results demonstrated that HIIT was superior to UC in improving peak oxygen uptake (VO2peak ). The SMD for VO2peak (L/min) and VO2peak (mL/kg/min) was 0.79 (95% CI 0.13, 1.45) and 0.59 (95% CI 0.01, 1.16), respectively. No significant differences in VO2peak were found between the HIIT and MICT groups. Meta-analyses on body composition and blood-borne biomarkers showed no significant differences between HIIT and UC. Systematic review indicated favorable effects of HIIT on muscle strength, fatigue, and emotional well-being. HIIT is a time-efficient alternative to MICT for improving VO2peak and may also enhance muscle strength and alleviate fatigue and emotional symptoms in breast cancer patients. HIIT should be considered as an important component of exercise prescription in breast cancer care. Further studies with larger cohorts are needed to determine the clinical significance of HIIT-induced changes in terms of other outcomes in women with breast cancer.

Effect of sleep and fatigue on cardiovascular performance in young, healthy subjects

Physical performance could be negatively affected by sleep deficiency and fatigue. The present study assesses the role of sleep quality, fatigue and motivation on cardiovascular performance (VO2peak, Wmax, and HRmax) in a sample of active young subjects.The current study is a cross-sectional design. Ninety-six university students (males 54.2%; 21.5 ± 2.9 yrs) completed an incremental exercise test on a bicycle ergometer. Sleep, fatigue, and motivation were assessed with the Pittsburgh Sleep Quality Index and two visual analogue scales, respectively. Differences in VO2peak, Wmax, HRmax, self-perceived fatigue and motivation were compared between good and bad sleepers and sleep duration >/<7.5 h, while regression analysis defined the predictors of VO2peak, Wmax, and HRmax.In the male sample, good and bad sleepers' differences were significant only for self-perceived fatigue (p = 0.04). The female sample showed no statistically significant differences between good and bad sleepers and different sleep durations. In the male sample, linear regression analysis showed a significant inverse correlation between Wmax and the PSQI score (-0.4, p = 0.004). The stepwise regression model indicated that sleep (β = -0.3, p = 0.02) was a significant predictor of VO2peak in males accounting for 20% of the variance, whereas physical performance seems more affected by fatigue (β = -0.4, p = 0.03) in females. In conclusion, chronic inadequate and self-reported sleep quality seems to be one of the factors compromising cardiovascular performance in males.

Long-term effects of cardiac rehabilitation after heart valve surgery - results from the randomised CopenHeartVR trial

Aims . The CopenHeartVR trial found positive effects of cardiac rehabilitation (CR) on physical capacity at 4 months. The long-term effects of CR following valve surgery remains unclear, especially regarding readmission and mortality. Using data from he CopenHeartVR Trial we investigated long-term effects on physical capacity, mental and physical health and effect on mortality and readmission rates as prespecified in the original protocol. Methods. A total of 147 participants were included after heart valve surgery and randomly allocated 1:1 to 12-weeks exercise-based CR including a psycho-educational programme (intervention group) or control. Physical capacity was assessed as peak oxygen uptake (VO2 peak) measured by cardiopulmonary exercise testing, mental and physical health by Short Form-36 questionnaire, Hospital Anxiety and Depression Scale, and HeartQol. Mortality and readmission were obtained from hospital records and registers. Groups were compared using mixed regression model analysis and log rank test. Results. No differences in VO2 peak at 12 months or in self-assessed mental and physical health at 24 months (68% vs 75%, p = .120) was found. However, our data demonstrated reduction in readmissions in the intervention group at intermediate time points; after 3, 6 (43% vs 59%, p = .03), and 12 (53% vs 67%, p = .04) months, respectively, but no significant effect at 24 months. Conclusions . Exercise-based CR after heart valve surgery reduces combined readmissions and mortality up to 12 months despite lack of improvement in exercise capacity, physical and mental health long-term. Exercise-based CR can ensure short-term benefits in terms of physical capacity, and lower readmission within a year, but more research is needed to sustain these effects over a longer time period. These considerations should be included in the management of patients after heart valve surgery.

Cystic fibrosis related diabetes is not associated with maximal aerobic exercise capacity in cystic fibrosis: a cross-sectional analysis of an international multicenter trial

BackgroundPrevious studies have reported differences in aerobic exercise capacity, expressed as peak oxygen uptake (VO2peak), 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 VO2peak. We investigated associations between CFRD and VO2peak following rigorous control for confounders including objectively measured physical activity. MethodsBaseline 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 VO2peak (mL.min−1) adjusting for a set of pre-defined covariates: age, sex, weight, forced expiratory volume in 1 s (FEV1), 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 VO2peak and CFRD. ResultsAmong 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 FEV1, physical activity, nutritional status, and other clinical characteristics. There were also no differences in VO2peak (mL.min−1 or mL.kg−1.min−1 or% predicted). In the final multivariable model, all pre-defined covariates were significant predictors of VO2peak (mL.min−1), however CFRD [coefficient 82.1, 95% CI -69.5 to 233.8, p = 0.28] was not. ConclusionsThis study suggests no meaningful differences in VO2peak between people with and without CFRD given comparable levels of physical activity.

Persistent dyspnea after COVID-19 is not related to cardiopulmonary impairment; a cross-sectional study of persistently dyspneic COVID-19, non-dyspneic COVID-19 and controls.

Background: Up to 53% of individuals who had mild COVID-19 experience symptoms for >3-month following infection (Long-CoV). Dyspnea is reported in 60% of Long-CoV cases and may be secondary to impaired exercise capacity (VO2peak) as a result of pulmonary, pulmonary vascular, or cardiac insult. This study examined whether cardiopulmonary mechanisms could explain exertional dyspnea in Long-CoV. Methods: A cross-sectional study of participants with Long-CoV (n = 28, age 40 ± 11 years, 214 ± 85 days post-infection) and age- sex- and body mass index-matched COVID-19 naïve controls (Con, n = 24, age 41 ± 12 years) and participants fully recovered from COVID-19 (ns-CoV, n = 14, age 37 ± 9 years, 198 ± 89 days post-infection) was conducted. Participants self-reported symptoms and baseline dyspnea (modified Medical Research Council, mMRC, dyspnea grade), then underwent a comprehensive pulmonary function test, cardiopulmonary exercise test, exercise pulmonary diffusing capacity measurement, and rest and exercise echocardiography. Results: VO2peak, pulmonary function and cardiac/pulmonary vascular parameters were not impaired in Long- or ns-CoV compared to normative values (VO2peak: 106 ± 25 and 107 ± 25%predicted, respectively) and cardiopulmonary responses to exercise were otherwise normal. When Long-CoV were stratified by clinical dyspnea severity (mMRC = 0 vs mMRC≥1), there were no between-group differences in VO2peak. During submaximal exercise, dyspnea and ventilation were increased in the mMRC≥1 group, despite normal operating lung volumes, arterial saturation, diffusing capacity and indicators of pulmonary vascular pressures. Interpretation: Persistent dyspnea after COVID-19 was not associated with overt cardiopulmonary impairment or exercise intolerance. Interventions focusing on dyspnea management may be appropriate for Long-CoV patients who report dyspnea without cardiopulmonary impairment.

Arthroscopic Bankart repair improves upper limb exercise capacity, shoulder function and quality of life.

Anterior glenohumeral instability is an important cause of shoulder disability. The aim of the present study was to investigate arm exercise capacity in patients with anterior glenohumeral instability before and after arthroscopic Bankart repair and to compare the results with those of healthy controls. The patient group included a total of 11 males between the ages of 18 and 40 years. The control group consisted of 13 healthy males with an age range of 23 to 41 years. An incremental arm crank exercise test was performed to determine upper limb exercise capacity, as expressed by peak oxygen consumption (VO2peak). The shoulder function of the patients was evaluated by the Western Ontario Shoulder Instability Index (WOSI), and the quality of life was assessed with the Short Form-36 (SF-36). All evaluations were performed preoperatively, and at the postop 3rd and 6th months. The patient group had lower VO2peak and exhaustion duration at the preoperative assessment (p = 0.025 and p = 0.007, respectively). SF-36 domains were lower in patients (p < 0.05). There were significant differences in VO2peak between preoperative and postop 6th-month measurements and between postop 3rd and 6th-month measurements (p < 0.001 and p = 0.001, respectively). The total WOSI score increased from preoperative 50.27% to 57.77% at the postop 3rd month, and to 65.56% at the final follow-up. Although improvements were detected in all SF-36 domains at postop follow-ups, they were not statistically significant except role limitations due to the physical problems domain (p = 0.006). There were no significant differences between controls and patients at the postop 3rd and 6th months with regard to exercise test parameters except the peak rating of perceived exertion. Shoulder function, exercise capacity, and quality of life were lower in the patient group and improved after arthroscopic Bankart repair. Clinicians should use the exercise capacity assessment for the evaluation of the recovery of shoulder function after providing stabilization.

Protein Supplementation Does Not Improve Aerobic and Anaerobic Fitness in Collegiate Dancers Performing Cycling Based High Intensity Interval Training.

The effects of a 6-week cycling high-intensity interval training (HIIT) concurrently with protein supplementation on aerobic and anaerobic fitness and body composition in collegiate dancers was investigated. Eighteen participants enrolled in a collegiate dance program were matched into three groups: high-protein (HP; 90 g˙d-1), moderate-protein (MP; 40 g˙d-1), and control (C; 0 g˙d-1). All participants performed a 6-week HIIT intervention. Participants completed a graded exercise test, Wingate anaerobic test (Wingate), and dual energy x-ray absorptiometry scan before and after the intervention. Peak heart rate (HRpeak), peak oxygen uptake (VOpeak), peak power output (PPO), lactate threshold (LT), and ventilatory thresholds 1 (VT1 ) and 2 (VT₂) were assessed during the graded exercise test. Peak power output, mean power output (MPO), and fatigue index (FI) were assessed during the Wingate. Lean mass (LM), fat mass (FM), visceral adipose tissue, appendicular skeletal muscle mass, and appendicular skeletal muscle mass index were assessed during dual energy x-ray absorptiometry. Body composition index (BCI) was calculated from pre and post LM and FM. Habitual diet was recorded weekly. Significance was set at p ≤ 0.05. No significant differences in VO2peak and percent fat mass (%FM) were observed between groups prior to the intervention. Significant main effects for time were observed for HRpeak (p = 0.02), VO2peak (p < 0.001), PPO (p < 0.01), LT (p < 0.001), VT1 (p < 0.001), and VT₂ (p < 0.001) during the graded exercise test, and PPO (p < 0.01) and FI (p < 0.01) during the Wingate. Significant main effects for time were observed for LM (kg; p = 0.01) and FM (kg; p < 0.01). Body composition index was improved for all groups, however, no significant differences by group were observed. No significant differences were observed between groups for the measured outcomes (p > 0.05). Therefore, there was no effect of protein supplementation in the short 6-week intervention. This cycling based HIIT routine increased physical fitness, optimized aesthetics, and was a simple addition to an existing collegiate dance curriculum.

Cardiorespiratory fitness and moderate-to-vigorous physical activity in older adults with multiple sclerosis.

BackgroundCardiorespiratory fitness (VO2peak) may be a modifiable indicator of health status and well-being in older adults with multiple sclerosis.PurposeWe examined differences in VO2peak and moderate-to-vigorous physical activity between older adults with multiple sclerosis and healthy controls, and whether moderate-to-vigorous physical activity accounted for group differences in VO2peak.MethodsOlder adults with multiple sclerosis (n = 31) and healthy controls (n = 29) completed a cardiopulmonary exercise test and wore an accelerometer for measuring moderate-to-vigorous physical activity. The data were analyzed using the Baron and Kenny approach for examining moderate-to-vigorous physical activity as a mediator of group differences in VO2peak.ResultsThe multiple sclerosis group had significantly lower VO2peak and moderate-to-vigorous physical activity than healthy controls. VO2peak had a large correlation with moderate-to-vigorous physical activity (r = .59). Group initially explained 8% of the variance in VO2peak (β = −0.29). The inclusion of moderate-to-vigorous physical activity accounted for an additional 27% of the variance in VO2peak, but only moderate-to-vigorous physical activity (β = 0.57) was a statistically significant correlate of VO2peak. The effect of Group was attenuated and non-significant with the addition of moderate-to-vigorous physical activity in Step 2 (Group β Step 1 = −0.29, Group β Step 2 = −0.05).ConclusionsOur results provide initial support for targeting moderate-to-vigorous physical activity as an approach for improving VO2peak in older adults with multiple sclerosis.

Lung function and peak oxygen uptake in chronic obstructive pulmonary disease phenotypes with and without emphysema.

Previous studies of associations of forced expiratory lung volume in one second (FEV1) with peak oxygen uptake (VO2peak) in chronic obstructive pulmonary disease (COPD) have not taken sex, age and height related variance of dynamic lung volumes into account. Nor have such demographic spread of spirometric measures been considered in studies comparing VO2peak between COPD phenotypes characterized by degree of emphysema. We aimed to assess the association of FEV1Z-score with VO2peak in COPD (n = 186) and investigate whether this association differs between emphysema (E-COPD) and non-emphysema (NE-COPD) phenotypes. Corresponding assessments using standardized percent predicted FEV1 (ppFEV1) were performed for comparison. Additionally, phenotype related differences in VO2peak were compared using FEV1Z-score and ppFEV1 as alternative expressions of FEV1. E-COPD and NE-COPD were defined by transfer factor of the lung for carbon monoxide below and above lower limits of normal (LLN), respectively. The associations were assessed in linear regression models. One unit reduction in FEV1Z-score was associated with 1.9 (95% CI 1.4, 2.5) ml/kg/min lower VO2peak. In stratified analyses, corresponding estimates were 2.2 (95% CI 1.4, 2.9) and 1.2 (95% CI 0.2, 2.2) ml/kg/min lower VO2peak in E-COPD and NE-COPD, respectively. The association did not differ statistically by COPD phenotype (p-value for interaction = 0.153). Similar estimates were obtained in analyses using standardized ppFEV1. Compared to NE-COPD, VO2peak was 2.2 (95% CI 0.8, 3.6) and 2.1 (95% CI 0.8, 3.5) ml/kg/min lower in E-COPD when adjusted for FEV1Z-score and ppFEV1, respectively. In COPD, FEV1Z-score is positively associated with VO2peak. This association was stronger in E-COPD but did not differ statistically by phenotype. Both the association of FEV1 with VO2peak and the difference in VO2peak comparing COPD phenotypes seems independent of sex, age and height related variance in FEV1. Mechanisms leading to reduction in FEV1 may contribute to lower VO2peak in E-COPD.

No Effect Of 8 Days Of Heat Acclimation On VO 2peak , Peak Power Output, Or Ventilatory Threshold

Adaptations from heat acclimation (HA) have been suggested to alter physiological responses during a maximal exercise test in trained individuals. These responses include a decreased oxygen cost for a given workload (improved exercise economy), or an increase in the power output at which the ventilatory threshold (VT) occurs; both factors that predict endurance performance. However, these findings are inconsistent in the literature, particularly in untrained individuals, therefore the effects of HA on maximal exercise responses remain unclear. PURPOSE: To examine any differences in VO2peak, peak power output (PPO), and VT pre- and post-HA in untrained individuals. METHODS: Thirteen healthy men (mean ± SD; age: 21 ± 3 yr; ht: 172 ± 8 cm; wt: 76 ± 13 kg) participated in the study. Subjects completed two peak oxygen consumption tests (VO2peak; on a cycle ergometer) that were separated by an 8-day exercise-HA protocol (treadmill walking: 5 km·hr-1, 2% grade; 40°C, and 40% RH). The VO2peak test workload started at 50-75 watts (W), and increased by 25 W every min until volitional exhaustion. Metabolic data were collected continuously over the course of the test. VT was determined using the ventilatory equivalence method (an increase in VE/VO2 with no change in VE/VCO2). The percent change in plasma volume (%ΔPV) was calculated from blood draws pre- and post-HA. A paired t-test was used to assess differences in physiological responses during the VO2peak test and from the HA protocol. Significance was set at an alpha level of P < 0.05. RESULTS: HA was achieved as indicated by a lower core temperature (Day 1: 38.1 ± 0.3 vs Day 8: 37.8 ± 0.3 °C; P < 0.01) and HR (Day 1: 134 ± 17 vs Day 8: 121 ± 13 bpm; P < 0.01) on Day 8 compared to Day 1. The %ΔPV from pre-to post HA was 22.8 ± 7.6 % over the course of the HA period. VO2peak (3.2 ± 0.4 vs 3.1 ± 0.5 L/min) and PPO (253 ± 37 vs 257 ± 38 W, P > 0.05 for both) were not different after 8 days of HA. There were no differences pre- to post-HA in VO2 (2.2 ± 0.4 vs 2.1 ± 0.4 L/min), power output (169 ± 27 vs 167 ± 31 W), VE (53.4 ± 9.6 vs 53.6 ± 10.8 L/min), or the RER (0.94 ± 0.05 vs 0.95 ± 0.06, P > 0.05 for all) at which VT occurred. CONCLUSION: An 8-day HA protocol did not lead to changes in VO2peak, PPO, or in the VO2 and PO at which the VT occurred during a peak oxygen consumption test. Supported by USARMDC; authors views not official US Army or DoD policy.

Effect of Sex, Body Mass Index and Physical Activity Level on Peak Oxygen Uptake Among 14-19 Years Old Adolescents.

The aim was to describe longitudinal trends in peak oxygen uptake (VO2peak) among 14- to 19-year-old adolescents in Norway, and to examine effects of sex, body mass index (BMI), and physical activity (PA) level on VO2peak during adolescence. Of 124 invited students from two lower secondary schools in Norway, 116 eighth-grade students (61 boys and 55 girls; 14 years old at baseline) volunteered to participate. The study has a longitudinal design with 6 yearly repeated measures of body height and mass, VO2peak and PA level. VO2peak allometrically scaled to body mass raised to the power of 0.67 was measured using a walking or running incremental test on a treadmill, whereas PA level was self-reported. Among 696 possible observations, 555 (79.7%) were valid. Multiple linear regression and linear mixed model analyses were used to examine the associations between age, sex, BMI, PA level and VO2peak. VO2peak showed a non-linear pattern from age 14 to 19, with a distinct increase for boys peaking at age 17, while the results provide a flatter and more stable curve for girls. Sex, BMI and PA level together explained 43–71% of the variance in VO2peak at the different age levels. Sex and PA level contributed independently to explain a significant proportion of the variance in VO2peak at all measurement occasions, while BMI did not. Adjusted sex differences in VO2peak increased over time, from 26.5 ml·kg−0.67·min−1 at age 14 to 55.5 ml·kg−0.67·min−1 at age 19. The independent contribution from PA level to the variance in VO2peak increased from age 14 to 16 and then decreased. While PA level explained 32.5% of the total variance in VO2peak for 16-year-olds, this number was 14% in 19-year-olds. In conclusion, aerobic power showed a non-linear pattern during adolescence, peaking at age 17. Sex and PA level explained a large proportion of the variance in VO2peak, each of them being an independent contributor to VO2peak. Aerobic power is linked to improved health and seems to depend largely on sex and PA level in adolescents, emphasizing the importance of maintaining a sufficient PA level during adolescence.

Lessons learned from a pilot randomized clinical trial of home-based exercise prescription before allogeneic hematopoietic cell transplantation.

Allogeneic hematopoietic cell transplantation (alloHCT) is a life-saving technology that can cure otherwise incurable diseases, but imposes significant physiologic stress upon recipients. This stress leads to short-term toxicity and mid- to long-term physical function impairment in some recipients. Exercise interventions have demonstrated preliminary efficacy in preserving physical function in HCT recipients, but the role of these interventions prior to HCT (prehabilitative) is less known. We tested a 5- to 12-week, prehabilitative higher intensity home-based aerobic exercise intervention in a randomized study of alloHCT candidates. Of 113 patients screened, 34 were randomized to control or intervention groups, 16 underwent pre- and post-intervention peak oxygen consumption (VO2peak) testing, and 12 underwent pre- and post-intervention 6-min walk distance (6MWD) testing. No significant differences in VO2peak or 6MWD were seen pre- to post-intervention between intervention and control groups, but final numbers of evaluable participants in each group were too small to draw inferences regarding the efficacy of the intervention. We conclude that the design of our prehabilitative intervention was not feasible in this pilot randomized study, and make recommendations regarding the design of future exercise intervention studies in alloHCT.

Cardiopulmonary exercise testing may not predict appropriate implantable cardioverter defibrillator therapies in heart failure patients

Background: The prognostic value of cardiopulmonary exercise testing (CPET) variables for major cardiovascular events in patients with heart failure (HF) is widely established. However, the prognostic value of these variables as predictors of appropriate implantable cardioverter-defibrillator (ICD) therapies has not been sufficiently well addressed. This study aimed to evaluate CPET variables such as peak oxygen uptake (VO2 peak), relationship between change in minute ventilation (VE) and carbon dioxide output (VCO2) during incremental exercise (VE/VCO2 slope) and exercise-related periodic breathing (EPB) as appropriate ICD therapy predictors in HF patients.Methods: We retrospectively assessed 61 HF patients who underwent CPET and had ICD implanted for primary prevention. Patients were followed for 767 ± 601 days. Primary outcome was appropriate ICD-delivered therapy, either anti-tachycardia pacing (ATP) or shock.Results: The sample consisted mostly of male patients (65.6%), with severe ventricular dysfunction (mean left ventricular ejection fraction (LVEF) 27 ± 6%). The primary outcome occurred in 20 patients (32%). There were no significant differences in VO2 peak (17.7 ± 4.1 and 16.9 ± 4.5 mL/kg/min), VE/VCO2 slope (39.7 ± 8.4 and 39.6 ± 10.2) or EPB prevalence (20% and 19.5%) in patients with or without appropriate ICD therapy. According to Cox regression analysis, none of the CPET variables were significant predictors of appropriate ICD therapy.Conclusions: In this cohort study of HF patients, CPET variables did not predict appropriate ICD therapies. Further studies with large number of patients are warranted to address this issue.