This study evaluated the sleep quality of athletes in normobaric hypoxia at a simulated altitude of 2,000 m. Eight male athletes slept in normoxic condition (NC) and hypoxic conditions equivalent to those at 2,000-m altitude (HC). Polysomnographic recordings of sleep included the electroencephalogram (EEG), electrooculogram, chin surface electromyogram, and electrocardiogram. Thoracic and abdominal motion, nasal and oral airflow, and arterial blood oxygen saturation (Sa(O(2))) were also recorded. Standard visual sleep stage scoring and fast Fourier transformation analyses of the EEG were performed on 30-s epochs. Subjective sleepiness and urinary catecholamines were also monitored. Mean Sa(O(2)) decreased and respiratory disturbances increased with HC. The increase in respiratory disturbances was significant, but the increase was small and subclinical. The duration of slow-wave sleep (stage 3 and 4) and total delta power (<3 Hz) of the all-night non-rapid eye movement sleep EEG decreased for HC compared with NC. Subjective sleepiness and amounts of urinary catecholamines did not differ between the conditions. These results indicate that acute exposure to normobaric hypoxia equivalent to that at 2,000-m altitude decreased slow-wave sleep in athletes, but it did not change subjective sleepiness or amounts of urinary catecholamines.

In the present study, we evaluated the duration of slow-wave sleep (Stage 3 and 4) and total delta power ( B3Hz) in all-night non-rapid eye movement (NREM) sleep electroencephalograms (EEGs) of athletes during normobaric hypoxia at simulated altitudes of 1500 m. Seven male athletes slept for two nights in a normoxic condition and one night in an hypoxic condition equivalent to an altitude of 1500 m. Whole-night polysomnographic recordings, thoracic and abdominal motion, nasal and oral airflow, and blood oxygen saturation (SpO 2 ) were recorded. Visual sleep stage scoring and fast Fourier transformation analyses of EEG were performed using 30-s epochs. Mean and minimum SpO 2 decreased significantly during sleep in the hypoxic condition. Between groups, changes in heart rate, respiratory disturbance measures including apnoea and hypopnoea, slow-wave sleep and total delta power of the all-night NREM sleep EEG were small and non-significant for the hypoxic condition . However, individual difference in time at an SpO 2 below 90% were large in the hypoxic condition, and both slow-wave sleep and total delta power of all-night NREM sleep EEG decreased in three participants who spent a prolonged time below 90% SpO 2 . The present results suggest that monitoring time below 90% SpO 2 is recommended when studying individuals' living-high schedule even under hypoxic conditions equivalent to an altitude of 1500 m.

Past studies have suggested that the cortisol awakening response (CAR) is a robust index for assessing daily stress. The present study examined the stability of CAR in individuals and the relationship between CAR and moods states and the influence of gender on CAR. CAR was measured in two successive days. Participants were student athletes (men=36, women=12) in a university athletic club that participated in club practice over five days a week. They were instructed to collect saliva just after and 30 minutes following awakening. The Moods was measured using the short form of the Profile of Moods States (POMS-S). The results indicated high stability of CAR values for the two successive days. Furthermore, there was a relationship between CAR and negative moods. Moreover, women showed significantly lager increases of the early morning free cortisol levels after awakening compared to men.

: Current collective e‹cacy research and future perspectives for sports groups: focusing on performance relativity and analysis methods. Japan J. Phys. Educ. Hlth. Sport Sci. 56: 491 506, December, 2011AbstractA study was conducted to obtain a perspective on the future directions of studies focusing on collective e‹cacy in Japan, including pertinent analytical methods, from three diŠerent viewpoints. First, preceding studies of sports groups in Europe and the USA were extensively reviewed, focusing on collective e‹cacy. This revealed that such studies had centered on group cohesion. It was also found that studies focusing on collective e‹cacy had tended to increase in recent years. Second, empirical studies of sports groups with respect to collective e‹cacy were reviewed, focusing particularly on its relationship with performance. Consequently, it was noted that, in general, collective e‹cacy was positively correlated with performance. Third, multilevel analysis of collective e‹cacy was examined to estimate its future applicability to sports psychology in Japan. Finally, we identiˆed the areas on which future collective e‹cacy studies of sports groups in Japan should be based, as few studies in this area have been conducted.

Recent field studies have reported the effects of exercise on the cortisol awakening response (CAR); however, no study has experimentally examined the effects. The purpose of this study was to investigate the effect of exercise intensity on CAR among 14 healthy male university students. Participants rested for 20 min (control condition) and exercised on a cycle ergometer for 20 min at 40% (low), 60% (moderate), and 80% (high) intensity of V・ O 2 max on separate days. Saliva samples were collected 10 times as follows: 1) before and 2) immediately after the experimental session, 3) 10 min, 4) 20 min, and 5) 30 min into the recovery period, 6) 9 PM and 7) 11 PM in the evening following the session, 8) immediately after awakening, 9) 15 min, and 10) 30 min post-awakening the day after the session. Cortisol concentration increased after the high-intensity exercise and recovered in the evening following the session. The 30 min post-awakening sampling point the day after the session of high-intensity exercise was higher than the control condition (p = .039). In addition, the higher intensity exercise condition led to the magnitude of change in CAR (CARc) (p = .006) and the area of cortisol increased under the curve (AUCi) (p = .034), making it higher than the control condition. There were no significant differences in other confounders. These results suggest that CAR showed a higher value in healthy male university students the day after performing high-intensity exercise.