ABSTRACT
A few studies have reported that nighttime sleep and daytime napping are significantly associated with sleep disorders, memory, concentration, cognitive ability, and academic performance in children. Moreover, sleep is identified as an important factor that has a profound effect on children’s athletic performance. If a short daytime nap is shown to benefit children involved in sports activities, this evidence could be used to improve children’s athletic performance in the afternoon. In this study, we investigated whether a short daytime nap could reduce the decline in athletic performance observed in the afternoon in children involved in basketball games. We investigated 10 elementary school-age male basketball players. The study was performed under two conditions, with and without a 20-min nap during the lunch break, and evaluation was performed under both conditions for 3 days each. The reaction and 20-m sprint times were measured after morning practice, before afternoon practice, and at the end of practice on all days. At the beginning of afternoon practice, the 20-m sprint time was significantly shorter (p<0.05) in the no-nap group (4.18±0.27 s) than in the nap group (4.24±0.24 s). In conclusion, our results suggest that a short daytime nap in children may reduce the decline in exercise performance observed in the afternoon.
ABSTRACT
The present study was conducted to examine whether stretching was effective to control muscular atrophy.Subjects were eight male undergraduate students (height 171.4 ± 5.8 cm, body weight 72.2 ± 7.8 kg, and age 20.6 ± 1.1 years) and the muscle analyzed was the vastus lateralis.Firstly, the subjects were instructed to perform strength training for a period of 16 weeks, which was followed by a 12-week detraining period. During the detraining period, either the right or the left leg was stretched daily for 10 minutes (2 sets). The mass of the vastus lateralis muscle was estimated based on its cross-sectional area (CSA), as assessed by magnetic resonance imaging (MRI). Relative decreases in muscle mass were compared between the stretched and the non-stretched control leg.Muscle mass in the non-stretched leg showed significant decreases during detraining, while no significant decreases in muscle mass were detected in the stretched leg. This outcome indicates that stretching can influence muscle plasticity and, therefore, is effective for preventing decreases in muscle mass.In conclusion, this study suggests that, added to its known ability to improve flexibility, accelerate recovery from fatigue, and prevent injuries, static stretching is effective for controlling muscle atrophy.