Changes in Brain Activity Immediately Post-Exercise Indicate a Role for Central Fatigue in the Volitional Termination of Exercise.

Electroencephalography (EEG) allows for the evaluation of real time changes in brain (electrocortical) activity during exercise. A few studies have examined changes in electrocortical activity using stationary cycling, but the findings have been mixed. Some of these studies have found increases in brain activity following exercise, while others have found decreases in brain activity following exercise. Hence, it is of importance to identify post-exercise changes in brain activity. Sixteen healthy, untrained subjects (8 males; 8 females) participated in the study. All 16 participants performed a graded exercise test (GXT) to volitional exhaustion on an upright cycle ergometer. Continuous EEG recordings were sampled before (PRE) and immediately following (IP) the GXT. Regions of interest were primarily the dorsolateral prefrontal cortex (DLPFC), ventrolateral prefrontal cortex (VLPFC), and left and right motor cortex (MC). In the DLPFC, a frontal asymmetry index was also identified. There was a statistically significant increase in theta power in the DLPFC, VLPFC, and left and right MC from PRE to IP (all p < 0.05). There was also a shift towards right hemisphere asymmetry at the IP time point in the DLPFC (p < 0.05). Finally, there was an increase in alpha power from PRE to IP in the right MC (p < 0.05). EEG could prove to be an important way to measure the effects of central fatigue on brain activity before and immediately following exercise.

Higher rating of perceived exertion and lower perceived recovery following a graded exercise test during menses compared to non-bleeding days in untrained females.

The underrepresentation of the female population in exercise sciences could be attributed, at least in part, to difficulty in appropriately accounting for the effects of the menstrual cycle (MC). Previous studies examining the effects of the MC on aerobic performance and subjective measures of aerobic performance show conflicting results. Purpose: The study examined how the MC affects the objective and subjective measures of aerobic performance within untrained female participants and in comparison with untrained male participants assessed at similar time intervals. Methods: Twenty-one participants (12 females and 9 males) completed a graded exercise test (GXT) on a cycle ergometer. The female participants were tested during their early follicular (EF; menses), ovulatory (O), and mid-luteal (ML) phases of the MC. The male participants were included as the control group and were randomly assigned to a menstrual cycle phase for each visit. During GXT, maximal oxygen consumption (VO2max), respiratory exchange ratio (RER), maximal heart rate (HRmax), peak blood lactate, and rating of perceived exertion (RPE) were determined. Twenty-four hours post-exercise, the perceived recovery status (PRS) was assessed. The MC phase was estimated using basal body temperature (BBT) in the female participants. Results: The male participants obtained a higher peak power and VO2max compared to the female participants (p < 0.05). All objective measures of aerobic performance did not significantly differ across the MC phases or time points that were tested. In the untrained female participants, an effect of the MC phase on RPE was found, with RPE being higher at EF (8.92 ± 0.79) compared to O (7.67 ± 1.23; p < 0.05) and ML (7.75 ± 1.06; p < 0.05). In addition, an effect of the MC phase on PRS was found, with perceived recovery being lower at EF (6.83 ± 0.94) compared to O (8.83 ± 1.12) and ML (8.67 ± 0.65; all p < 0.005) for the untrained female participants. No significant differences in RPE and PRS were found between tests in the untrained male participants. The female participants had lower perceived recovery following EF (6.83 ± 0.94) compared with the male participants (9.00 ± 1.00; p < 0.001). Conclusion: The untrained female participants perceived greater exertion during GXT and impaired recovery following GXT in EF compared to O and ML. These results may be attributed to either a drop in female sex hormone concentrations or discomfort associated with menses. The male participants did not exhibit any changes over time. Future studies using subjective parameters such as perceived exertion to track the internal load of training in the naturally menstruating female population should consider menses.

Social Distancing, Psychological Mood and Physical Activity Behavior During COVID-19 in the United States.

Social distancing, during previous epidemics, has been shown to lead to poor mental health outcomes and reduced physical activity. The purpose of the present study was to examine the relationships between self-reported psychological state and physical activity behaviors of individuals under social distancing policies during the COVID-19 pandemic. 199 individuals (29.85 ± 10.22 yrs) in the United States who had been in social distancing for 2-4 weeks participated in this study. Participants answered a questionnaire regarding feelings of loneliness, depression, anxiety, mood state, and physical activity. 66.8% of participants had depressive symptoms and 72.8% had symptoms of anxiety. Loneliness was correlated with depression (r = 0.66), trait anxiety (r = 0.36), fatigue (r = 0.38), confusion (r = 0.39), and total mood disturbance (TMD; r = 0.62). Participation in total physical activity was negatively associated with depressive symptoms (r = -0.16) and TMD (r = -0.16). State anxiety was positively associated with participation in total physical activity (r = 0.22). In addition, a binomial logistic regression was performed to predict participation in sufficient physical activity. The model explained 45% of the variance in physical activity participation and correctly categorized 77% of cases. Individuals with higher vigor scores had an increased likelihood of participating in sufficient physical activity. Loneliness was associated with negative psychological mood state. Individuals with higher feelings of loneliness, depressive symptoms, trait anxiety, and negative mood state were observed to spend less time engaged in physical activity. Higher state anxiety was positively associated with engagement in physical activity.