In this model, 21-d forearm immobilization caused no significant changes in forearm muscle morphology, but the muscle function showed remarkable deterioration ranging from 18 to 45%.

This study investigated effects of home confinement on physical activity (PA) in Team Handball during the COVID-19 outbreak. A total of 1359 handball players participated (age: 23 ± 6 years). Participants from Europe, Western Asia, and North Africa answered an online version of the International Physical Activity Questionnaire (IPAQ) considering “before” and “during” confinement. COVID-19 home confinement has had a negative effect on PA (vigorous, moderate, walking, and overall). The largest decrease was in the sum parameter “all PA” (MET (metabolic equivalent of task)-minutes/week, ηp2 = 0.903; minutes/week, ηp2 = 0.861). Daily sitting time increased from 2.7 to 5.0 h per weekday (p < 0.001, ηp2 = 0.669). For gender, continent, country, level of handball league, and playing position, no significant differences (group and interaction effects) were observed. The largest change in PA behavior was in walking (minutes per day: ηp2 = 0.755), with males displaying the greatest decrease (from 62 ± 11 to 30 ± 14 min per weekday; d = 2.67). In terms of magnitude, difference between genders was greatest for sitting time (difference in d = 1.20). In conclusion, while COVID-19 measures were essential to preserve public health, PA was compromised and sedentary behavior increased because of these public health measures regardless of gender, playing position, and competition level.

The results of this study suggest that T1/2reoxy time was prolonged with aging, regardless of habitual physical activity levels. However, habitual physical activity may prevent the age-related prolongation in T1/2reoxy time after CycEXmax. VO2peak appears to be one of the major factors determining T1/2reoxy time, not age.