Effects of physical positions on sleep architectures and post-nap functions among habitual nappers

Effects of a 20-Min Nap Post Normal and Jet Lag Conditions on P300 Components in Athletes

“…Most of the studies that examined the effects of napping on alertness [1], cognitive performance [17], or motor imagery learning [13] were conducted in the elderly, shift workers or young healthy subjects, and all showed that napping, whatever the duration, was effective in enhancing cognitive performance. Those that evaluated alertness with P300 were less numerous and were conducted only in healthy subjects [32,40,47] or patients (for review see [18]) but never in athletes. Zhao et al [47] and Milner et al [32] showed in young habitual nappers that a nap, in normal sleep conditions, enhances vigilance, i. e. increases P300 amplitude and decreases P300 latency.…”

“…Those that evaluated alertness with P300 were less numerous and were conducted only in healthy subjects [32,40,47] or patients (for review see [18]) but never in athletes. Zhao et al [47] and Milner et al [32] showed in young habitual nappers that a nap, in normal sleep conditions, enhances vigilance, i. e. increases P300 amplitude and decreases P300 latency. According to these authors [47], the recuperative nature of short-term naps should be attributed to the delta activity during stage 2 sleep.…”

“…Zhao et al [47] and Milner et al [32] showed in young habitual nappers that a nap, in normal sleep conditions, enhances vigilance, i. e. increases P300 amplitude and decreases P300 latency. According to these authors [47], the recuperative nature of short-term naps should be attributed to the delta activity during stage 2 sleep. Like these authors, we also found a significant amount of stage 2 (52.2 ± 20.82 %) during napping, which may have been sufficient to help restore the daytime vigilance level [21,43] and lead to higher cortical arousal [47].…”

Central fatigue and sympathovagal imbalance during night shift in Japanese female nurses

“…In addition, Hayashi et al (1999) suggested that a 20 min nap as a countermeasure to post-lunch sleepiness has positive effects on subsequent insomnia; therefore, the negative effects on Biological Rhythm Research 11 sleep inertia are negligible. In young subjects, sleepiness and fatigue are improved, along with restorative capabilities, with habitual day-time napping for about 20 min (Zhao et al 2010). In contrast, 50 min napping is least effective because subjects are awakened from slow-wave sleep (SWS) leading to increased sleep inertia in the mid-afternoon.…”

“…It has been shown that a 20 min nap in the day time has beneficial restorative effects upon the maintenance of arousal level, however, the effects of a 20 min nap during the night are unclear (Hayashi et al 1999;Zhao et al 2010). In the present study, during napping, LF/HF ratio and HF norm showed similar hyperbolic curves during sleep in both groups.…”