HMB added to whey did not result in greater increases in any measure of muscle mass, strength, or hormonal concentration compared to leucine added to whey. Our results show that HMB is no more effective in stimulating RT-induced hypertrophy and strength gains than leucine.

Objective To evaluate the construct validity and responsiveness of the Rapid Assessment of Physical Activity (RAPA) for measuring physical activity (PA) in adults living with HIV. Design Secondary analysis of an interrupted time-series intervention study. Setting Community-based fitness facility in Toronto, Canada. Participants Sixty-seven adults (N=67) living with HIV (n=5 women; mean age, 51.8±11.6 years) with available baseline data to assess for construct validity of the RAPA, of which 50 (n=4 women; age, 53.2±11.4 years) had follow-up data to evaluate responsiveness. Interventions Two months of a community-based exercise intervention involving thrice weekly multicomponent exercises. Main Outcome Measures We used a single-item PA questionnaire as a convergent outcome to the RAPA, while peak oxygen consumption, general health status, and number of concurrent health conditions were divergent outcomes. We tested 11 a priori hypotheses (6 construct validity, 5 responsiveness) using Spearman ρ, Wilcoxon signed-rank tests, Cohen's d , standardized effect size (SES), and standardized response mean (SRM). We considered acceptable construct validity and responsiveness if >75% of hypotheses were confirmed. Results All of the hypotheses (100%) for construct validity were confirmed. The RAPA demonstrated moderate correlations with the single-item PA questionnaire (ρ=0.61), and negligible correlations with divergent outcome measures (ρ=0.08-0.21). Two of the 5 hypotheses (40.0%) for responsiveness were confirmed. RAPA scores were significantly greater after 2 months of training ( P <.001) and demonstrated a small to moderate effect size ( d =0.50, SES=0.47, SRM=0.48). There was a low correlation between change in RAPA scores and change in single-item PA questionnaire scores (ρ=0.48). Conclusions The RAPA demonstrated acceptable construct validity and poor responsiveness in adults living with HIV. Therefore, the RAPA can be used cross-sectionally but may be used in conjunction with other measures of PA for adults living with HIV.

Smoking is an important risk factor for cardiovascular disease and all-cause mortality. Cardiac rehabilitation (CR) is effective for reducing the risk of recurrent cardiac events through improving cardiorespiratory fitness (CRF). Little is known about the influence of smoking on CRF throughout long-term CR. The purpose of this analysis was to compare CRF trajectories among individuals with positive and negative smoking history enrolled in long-term CR. Participants had a positive smoking history if they currently smoke or formerly smoked (Smoke+, n=55, mean age=64.9 ± 9.0 years) and had a negative history if they never smoked (Smoke–, n=34, mean age=61.4 ± 9.0 years). CRF (VO2peak) was measured at baseline and annually thereafter for 6 years. The Smoke+ group had lower CRF compared to the Smoke– group over enrollment (β=-3.29 (SE=1.40), 95% CI -6.04, -0.54, p=0.02), but there was no interaction of smoking history and enrollment (β=0.35 (SE=0.21), 95% CI -0.06, 0.77, p=0.10). Moreover, trajectories were not influenced by pack-years (β=0.01 (SE=0.01), 95% CI -0.01, 0.04, p=0.23) or time smoke-free (β=-0.002 (SE=0.01), 95% CI -0.02, 0.02, p=0.80). Although the trajectories of CRF do not appear to be affected by smoking behaviour, individuals without a history of smoking maintained higher CRF throughout enrollment. Novelty bullets: • The benefits of long-term exercise-based cardiac rehabilitation on cardiorespiratory fitness are similar between those who have smoked and those who have never smoked. • Neither the number of pack-years nor the length of time spent smoke-free influence cardiorespiratory fitness trajectories following long-term cardiac rehabilitation.

BackgroundStroke is a highly disabling condition and is the second leading cause of death globally. Engaging in aerobic exercise is important for the prevention of a recurrent stroke through improving markers of cardiovascular health such as blood pressure and arterial stiffness. While higher intensities of aerobic exercise generally elicit greater cardioprotective effects, little is known about the acute cardiovascular effects of a single session of high intensity aerobic exercise in people with stroke. The objective of this study was to model the recovery of arterial stiffness (carotid-femoral pulse wave velocity, cfPWV), heart rate and blood pressure following peak intensity aerobic exercise in individuals with chronic stroke.MethodsTen participants with chronic stroke (mean ± SD age = 56.9 ± 11.8 years, median [IQR] years post-stroke = 2.9 [1.9]) performed a symptom-limited cardiopulmonary exercise test (CPET) on a recumbent stepper. Before the CPET, resting cfPWV, heart rate and blood pressure were measured. Immediately following the CPET, all outcomes were measured again continuously for 20 min to use all available observations (n = 245 observations) and capture any potential non-linear changes. Mixed model analyses were then applied to model post-exercise changes of cfPWV, heart rate and blood pressure.ResultsCarotid-femoral pulse wave velocity was increased from rest following the CPET (9.0 ± 0.53 to 9.9 ± 0.52 m/s, p &lt; 0.001) and remained elevated for 20 min into post-exercise recovery, independent of heart rate (p = 0.001). Heart rate also increased from baseline (71.2 ± 3.2 to 77.4 ± 3.1 bpm, p &lt; 0.001) and remained elevated for 10 min post-exercise (p &lt; 0.001). Finger systolic blood pressure was reduced from rest (117.3 ± 4.7 to 111.8 ± 4.6 mmHg, p &lt; 0.001) and remained reduced for 15 min after exercise (p &lt; 0.001). There were no significant differences in finger diastolic or mean arterial pressures from rest.ConclusionThis was the first study to capture continuous changes in cfPWV following peak aerobic exercise in any clinical population. The present study revealed that cfPWV is elevated for 20 min after peak aerobic exercise in individuals with stroke, which was independent of heart rate. These findings suggest there may be autonomic imbalances in large arteries following peak intensity aerobic exercise in individuals with stroke.

BACKGROUND: Low frequency vibrations from motorized vehicles and heavy equipment have been associated with musculoskeletal disorders. Spine degeneration on diagnostic imaging provides direct and objective measures of the possible effects of such exposures on the spine. OBJECTIVE: The objective of this systematic review was to evaluate the association of exposure to whole-body vibration (WBV) with spine degeneration on imaging. METHODS: We conducted electronic searches in MEDLINE, CINAHL, EMBASE, and Web of Science to July 2021. Two reviewers independently screened search results, assessed quality, and extracted data. Studies evaluating the exposure to WBV and lumbar spine degeneration on imaging were included. RESULTS: Fifteen studies (16 manuscripts) were included. Seven studies including a meta-demonstrated moderate quality evidence of no association between WBV and disc degeneration. There was also moderate quality evidence of no association between WBV and disc height narrowing and osteophytes. Overall, there was low level evidence of no association between WBV and other degenerations findings. CONCLUSIONS: There was moderate to low quality evidence suggesting no association between WBV exposures with spine degeneration on imaging. The results of this study currently do not support assertion that motorized vehicle and WBV exposure accelerates degeneration and causes structural damage to the spine.