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Objective: The present study aimed to examine the acute effects of legal-market cannabis on regular cannabis users' subjective responses to exercise in a controlled laboratory environment., Background: Given the stereotype that cannabis is associated with extreme sedentary behavior, there are concerns that cannabis legalization may exacerbate the US physical inactivity epidemic. However, despite these concerns, recent years have seen considerable public interest in the use of cannabis concurrently with exercise (e.g., running)., Methods: The present study compared participants' experiences of exercise without cannabis to their experiences of exercise after acute ad libitum use of one of two commercially available cannabis flower products: a Δ9-tetrahydrocannabinol-dominant or a cannabidiol-dominant product. Participants (N = 42) were regular cannabis users between the ages of 21 and 39 years (mean = 30.81 years, standard deviation = 4.72 years)., Results: Although participants reported a more positive affect (p < 0.001), enjoyment (p < 0.001), and runner's high symptoms (p < 0.001) during their cannabis (vs non-cannabis) exercise appointment, they also reported more exertion (p = 0.04). Pain levels were very low and did not differ between appointments (p = 0.45). Effects appeared to depend, in part, on cannabinoid content; there was a larger difference in enjoyment (p = 0.02), and a smaller difference in exertion (p = 0.02), between the cannabis and non-cannabis exercise appointments among participants in the cannabidiol (vs Δ9-tetrahydrocannabinol) condition., Conclusions: To our knowledge, this is the first study to investigate the acute effects of commercially available cannabis on subjective responses to exercise in a laboratory environment. Our findings suggest that, among regular cannabis users who use cannabis in combination with exercise, cannabis use prior to exercise may lead to increases in both positive and negative aspects of the subjective exercise experience. Research using diverse samples, exercise modalities, and methodologies (e.g., placebo-controlled trials) is needed to establish the generalizability of these findings., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Objective: Consistent with the Science of Behavior Change (SOBC) experimental medicine approach, this early phase intervention development study examines the influence of an intervention strategy (exercise training) on a behavioral health outcome (exercise engagement) in the service of addressing a widespread threat to public health (physical inactivity). Method: Physically inactive participants ( N = 201) were randomly assigned to one of four exercise training conditions fully crossed on intensity (moderate, vigorous) and duration (short, long). Training occurred over 16-weeks and in-bout assessments of affective response (valence) and ratings of perceived exertion (RPE) were collected during Weeks 1, 4, 8, and 16. Cardiorespiratory fitness (VO₂max) was assessed pre- or postintervention and exercise behavior was assessed at 6-months postintervention follow-up. Results: Across conditions, affective response to exercise did not change, on average, over 16-weeks. Conversely, RPE decreased slightly, on average, over time. Participants completing vigorous intensity exercise reported more negatively valenced affective response and higher RPE, on average, across weeks. Greater total exercise volume completed and greater change in VO₂max were associated with more negatively valenced affective response, on average. Baseline affective response scores were positively associated with exercise minutes at follow-up; however, average affective response scores across the intervention were not associated with minutes of exercise at follow-up. Conclusions: Affective response to exercise did not become more positive in valence over time as a function of training volume or change in VO₂max. Implications for translating these findings to inform future intervention development efforts are discussed. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Objectives: Cannabis use is increasing among older adults. We examined whether cannabis use impacted results of an intervention to increase physical activity in sedentary adults aged 60 and over. Methods: We measured differences in body mass index (BMI), exercise behavior, and cardiovascular fitness between older adult cannabis users (N = 28) and nonusers (N = 136) participating in an exercise intervention trial. Results: BMI of cannabis users was significantly lower than non-users (p = .007). Cannabis users reported .70 more days of exercise on the Stanford 7-Day Physical Activity Recall than non-users at the 8-week timepoint (p = .068) and were 4.1 points higher on the exercise subscale of the Community Healthy Activities Model Program for Seniors at 16-weeks (p = .045). Neither baseline nor post-intervention fitness differed by cannabis use status, and cardiovascular fitness improved after intervention in the full sample. Conclusion: These preliminary data suggest that current cannabis use status is not associated with a negative impact on fitness and efforts to increase exercise in sedentary older adults. Future studies should collect more detailed information on patterns and forms of cannabis use to understand their potential health effects for older adults.

In hypoxia, endurance exercise performance is diminished; pharmacotherapy may abrogate this performance deficit. Based on positive outcomes in preclinical trials, we hypothesized that oral administration of methazolamide, a carbonic anhydrase inhibitor, aminophylline, a nonselective adenosine receptor antagonist and phosphodiesterase inhibitor, and/or methazolamide combined with aminophylline would attenuate hypoxia-mediated decrements in endurance exercise performance in humans. Fifteen healthy males (26 ± 5 years, body-mass index: 24.9 ± 1.6 kg/m(2); mean ± SD) were randomly assigned to one of four treatments: placebo (n = 9), methazolamide (250 mg; n = 10), aminophylline (400 mg; n = 9), or methazolamide (250 mg) with aminophylline (400 mg; n = 8). On two separate occasions, the first in normoxia (FIO2 = 0.21) and the second in hypoxia (FIO2 = 0.15), participants sat for 4.5 hours before completing a standardized exercise bout (30 minutes, stationary cycling, 100 W), followed by a 12.5-km time trial. The magnitude of time trial performance decrement in hypoxia versus normoxia did not differ between placebo (+3.0 ± 2.7 minutes), methazolamide (+1.4 ± 1.7 minutes), and aminophylline (+1.8 ± 1.2 minutes), all with p > 0.09; however, the performance decrement in hypoxia versus normoxia with methazolamide combined with aminophylline was less than placebo (+0.6 ± 1.5 minutes; p = 0.01). This improvement may have been partially mediated by increased SpO2 in hypoxia with methazolamide combined with aminophylline compared with placebo (73% ± 3% vs. 79% ± 6%; p < 0.02). In conclusion, coadministration of methazolamide and aminophylline may promote endurance exercise performance during a sojourn at high altitude.

Improved endurance exercise performance in adult humans after sprint interval training (SIT) has been attributed to mitochondrial biogenesis. However, muscle protein synthesis (MPS) and mitochondrial biogenesis during SIT have not been measured, nor have sex-specific differences. We hypothesized that males and females would have similar rates of MPS, mitochondrial biogenesis, and synthesis of individual proteins during SIT. Deuterium oxide (D2O) was orally administered to 21 adults [11 male, 10 female; mean age, 23±1 yr; body mass index (BMI), 22.8±0.6 kg/m(2); mean± SE] for 4 wk, to measure protein synthesis rates while completing 9 sessions of 4-8 bouts of 30 s duration on a cycle ergometer separated by 4 min of active recovery. Samples of the vastus lateralis were taken before and 48 h after SIT. SIT increased maximum oxygen uptake (VO(2max), males 43.4±2.1-44.0±2.3; females 39.5±0.9-42.5±1.3 ml/kg/min; P=0.002). MPS was greater in the males than in the females in the mixed (~150%; P < 0.001), cytosolic (~135%; P=0.038), and mitochondrial (~135%; P=0.056) fractions. The corresponding ontological clusters of individual proteins were significantly greater in the males than in the females (all P<0.00001). For the first time, we document greater MPS and mitochondrial biogenesis during SIT in males than in females and describe the synthetic response of individual proteins in humans during exercise training., (© FASEB.)

This study utilized a randomized control trial to examine whether structural changes in the precuneus, insula, caudate, hippocampus, and putamen were related to exercise. A total of 197 healthy older adults with no evidence of dementia participated in moderate-intensity interval training or low-intensity continuous training for 16 weeks. Size decreased in the right hippocampus such that the effect of time was significant but the interaction with condition was not. For the left hippocampus, size decreased in the low-intensity continuous training condition but increased in the moderate-intensity continuous training plus interval training condition at the trend level. Finally, there was a significant time-by-condition interaction such that the thickness of the left insula increased for low-intensity continuous training and decreased for moderate-intensity continuous training plus interval training. Few structural changes were associated with the exercise intervention. Future studies should examine the effects of exercise on brain structure in high-risk or clinical populations for a longer period of time. [ABSTRACT FROM AUTHOR]