A temporal study of the effects of sleep inertia and alertness on physical activity

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K11458
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 59020:Sports sciences-related
• Research Institution: Waseda University
• Principal Investigator: Nishida Masaki 早稲田大学, スポーツ科学学術院, 教授 (10424029)
• Co-Investigator(Kenkyū-buntansha): 塩田 耕平 金沢星稜大学, 人間科学部, 講師 (40638962)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 睡眠 / スポーツ / 身体運動 / 睡眠慣性 / 仮眠

Outline of Final Research Achievements

The present study aimed to demonstrate changes in sleep inertia and physical exercise capacity over time. When grip strength was compared before and after different nap duration conditions, a significant decrease in grip strength was observed in the 60-minute nap condition, compared to no nap and a 20-minute nap. In Experiment 2, the experimental task was sports stacking, which requires skillful technique, and during the nap, EEG was recorded and the subjects were awakened at different sleep stages and compared with their performance before the nap. The time required for sports stacking was significantly prolonged when the participants were awakened in the third stage of non-REM sleep, compared to before the start. These results indicate that some athletic performance is reduced when strong sleep inertia is activated, such as during a 60-minute nap or when the subject is awakened in the third stage of non-REM sleep.

Free Research Field

睡眠科学　スポーツ科学　臨床精神医学

Academic Significance and Societal Importance of the Research Achievements

本研究の成果は、アスリートの練習や競技試合のスケジュール策定と、それに合わせるコンディショニングに役立つ。朝練習を日課としているアスリートは、睡眠不足や午後のパフォーマンス低下に悩んでいる。また若年者は夜型のクロノタイプをもつことが多く、起床時の覚醒度が低いため、起床・覚醒してすぐの運動は、不測のケガも生じやすい。運動の種類によっても異なるが、覚醒から身体運動開始まで約30分の時間間隔が望ましいこと、運動刺激によってこの時間間隔は短縮される。この結果から、夜間睡眠から覚醒後の朝練習、仮眠から覚醒後の午後のトレーニングでは、30分程度の十分な時間間隔と、十分なウォーミングアップが望ましい。