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Background: COVID-19 restrictions and alterations to daily living (e.g. working from home, caregiving responsibilities) necessitated changes in physical activity (PA) behavior. Purpose: The purpose of this study is to understand how PA within specific domains and behavior settings changed during the COVID-19 pandemic. Methods: An e-survey, conducted April-June 2020, examined changes in PA across domains and settings in a national sample of adults (N=805; M age=38.7 ± 14.9 yrs; 78.0% female). Results: Respondents reported domain-specific increases in household and recreational PA, but decreases in active transportation, occupational PA, and public transportation use. Weekly minutes of PA changed significantly across all behavior settings, with reported increases in home-based, neighborhood, parks/trails, and total PA, and decreases in PA through recreational sports and fitness facilities. Total weekly PA minutes increased by 10.6% (Z= 4.428, p < .000). Those with caregiving responsibilities reported increases in household PA (2=9.82, p=0.007) and PA frequency (2=8.21, p=0.02). Those without caregiving responsibilities were more likely to report increases in sitting (2=20.55, p more...

The aim of this study was to determine if an abnormal HRV status would have negative effects on simulated individual time trial (ITT) performance in recreational cyclists. Recreational male (n=23, 42.8±8.3 years, 78.0±11.0 kg) and female (n=2, 37.0±6.8 years, 68.0±4.4 kg) cyclists completed simulated indoor 40-minute ITTs (40TT) over ten weeks. Participants were asked to complete simulated 40TTs under two HRV conditions: HRV normal values and HRV abnormal values. Participants recorded daily morning HRV readings to determine HRV status. Each participant performed all 40TTs on their personal indoor bike trainer and bike without external race simulation (e.g., Zwift). All cycling performance data were recorded on personal bike computers and submitted via a Qualtrics survey. A total of 138 ITTs (Normal = 75; Abnormal = 63) were assessed for relationships between HRV status and performance outcomes using a linear mixed-effects model with Cohen’s D for effect sizes (ES). A significant main effect of HRV status was found for peak power (F = 6.61; Normal: 372 ± 121.5 watts; Abnormal: 349 ± 105.9 watts; 380; p = 0.01; ES = 0.20) and peak speed (F = 6.12; Normal = 10.8 ± 1.2 m/s; Abnormal: 10.4 ± 1.2 m/s; p = 0.02; ES = 0.33). No significant main effect or effect sizes exceeding 0.20 were observed for all other performance variables. Daily HRV monitoring provides valuable insight that an individual’s peak power and speed may be compromised during cycling performance despite no changes in physiological or psychological indicators of effort. Coaches and cyclists can use morning HRV to inform race strategy ensuring desired performance outcomes, especially for those who rely on high power outputs more...

Physical activity (PA) classes help college students add weekly PA, which can help improve health and maintain body weight. Traditional weight training (TWT) can improve strength and aerobic capacity. High-intensity functional training such as CrossFit® (CF) provides time-efficient workouts with both muscle strengthening and aerobic exercises. Limited research has compared these classes for college students. We examined changes in muscular strength, power, and endurance as well as body composition. Participants were 85 healthy college students enrolled in TWT (n = 36, age 22.6 ± 4.1 years, 72.2% male) or CF (n = 49, age 21.8 ± 3.2 years, 55.1% male) classes meeting twice/wk for 8 weeks between October 2017 and May 2018. Baseline and posttest measurements included a vertical jump, grip strength, a 2 min push-up test, a 1 min squat test, height, weight, and a bioelectrical impedance analysis. Although no significant group × time interactions were found, there was a significant main effect of time for push-ups and squats (both p &lt, 0.001). Participants enjoyed the classes and most planned to continue. Both classes improved muscular endurance although no significant differences were found between them. Activity classes provide college students with an option for increasing their weekly PA and help maintain body composition. Future research should examine the benefits from longer or more frequent classes. more...

High-intensity exercise interventions are often promoted as a time-efficient public health intervention to combat chronic disease. However, increased physical effort and subsequent fatigue can be barriers to long-term maintenance of high-intensity exercise programs. The purpose of the present study was to determine if heart rate variability (HRV) mediated state traits related to exercise program adherence. Fifty-five healthy men and women (ages 19–35 years) used a commercially available smartphone application to monitor daily HRV status throughout a 6-week high-intensity exercise intervention. Participants reported state motivation to exercise and global physical fatigue immediately prior to each exercise session. Temporary shifts toward increased parasympathetic reactivation (p = 0.030) resulted in significant increases in daily fatigue (p < 0.001) and decreases in motivation to exercise (p = 0.028). Through modulation of exercise volume, in response to these temporary shifts in HRV, these effects were reversed (p < 0.001) via increased parasympathetic withdrawal (p = 0.018). For the first time, these data demonstrate a mediating effect of HRV on adherence-related trait states throughout a high-intensity exercise program. Applied strategies, such as appropriately timed exercise volume moderation, may be able to leverage this effect and help facilitate long-term exercise program maintenance. Novelty These data establish a link between expected shifts in HRV throughout high-intensity exercise programs with motivation to participate and physical fatigue. Modulation of training volume, in response to these shifts, can optimize adherence-related behavioral responses during high-exercise programs. more...