Good Sleep Group Research Articles

Exercise and sleep.

This paper reviews the literature on the association between exercise and sleep. The epidemiological and experimental evidence for whether or not acute and chronic exercise promote sleep is discussed, as well as moderating factors and agendas for future directions of study. The expectation that exercise will benefit sleep can partly be attributed to traditional hypotheses that sleep serves energy conservation, body restoration or thermoregulatory functions, all of which have guided much of the research in this field. Exercise is a complex activity that can be beneficial to general well-being but may also stress the body. Differences in the exercise protocols studied (e.g. aerobic or anaerobic, intensity, duration) and interactions between individual characteristics (e.g. fitness, age and gender) cloud the current experimental evidence supporting a sleep-enhancing effect of exercise. In addition, the tendency to study changes in small groups of good sleepers may also underestimate the efficacy of exercise for promoting sleep. Athough only moderate effect sizes have been noted, meta-analytical techniques have shown that exercise increased total sleep time and delayed REM sleep onset (10 min), increased slow-wave sleep (SWS) and reduced REM sleep (2-5 min). The sleep-promoting efficacy of exercise in normal and clinical populations has yet to be established empirically.

Classification of the sleeping pattern of normal adults.

A questionnaire concerning their sleep-related lifestyle and mental health was mailed to people aged in their twenties to fifties living in the Fukushima (North East), Tokyo (Central, Metropolitan) and Okayama (West) areas of Japan. We classified the sleeping pattern of 3642 people (1702 men, 1940 women; mean age 41.3+/-10.67) by multivariational analyses (factor analysis and cluster analysis). They were classified into six groups and defined as 'poor sleeper group' (30.0%), 'good sleeper group' (28.3%), 'long sleeper group' (8.2%), 'short sleeper group' (18.5%), 'irregular sleeper group' (11.3%), and 'Delayed Sleep Phase Syndrome group' (3.7%) based on their characteristics of the factor pattern.

Melatonin and hormonal changes in disturbed sleep during late pregnancy

Although sleep disturbance is commonly reported in pregnancy, there have been surprisingly few studies on the etiology of this condition. Since most hormones show circadian rhythmicity and maintain specific phase relationships with that of the sleep-wake cycle, it was of interest to establish whether sleep disturbances covaried with endocrine changes. This overnight study of pregnant women compared melatonin, cortisol, and prolactin secretion rhythms in six good sleepers and six poor sleepers. The groups were compared by ratios of the areas under the various hormonal curves. Significant differences in the cortisol/melatonin ratio were found between the poor sleeper group (lower values) and the good sleeper group (higher values). Nonsignificant trends, which might be expected to become significant with larger sample sizes, were found for decreased amplitude in the cortisol rhythm and increased amplitude in the melatonin rhythm in poor sleepers. The decreased amplitude of the cortisol rhythm in poor sleepers appeared to be due to a suppression of the early morning (0500-0800) rise. Prolactin levels were high and showed no rhythmicity in both groups. These differences may reflect changes in the circadian pacemaker system of poor sleepers, with increases in melatonin release being a response to counteract poor sleep.

Recuperation du sommeil apres privation: Comparaison entre bons et mauvais dormeurs de meme age

Sleep organization was studied with and without a previous sleep deprivation. Sleep recovery was allowed during day or only at night. Two groups of good and poor sleepers were compared (15 subjects aged 22-26 years in each). The main differences between groups were observed for 1) the sleep onset latency 2) the ratio total sleep time/time in bed and on the total sleep time. The influence upon sleep of the various situations was less marked in poor sleepers than in good sleepers. This result suggests some deficiency in the mechanisms allowing sleep recovery after deprivation.

Daytime alertness in subjective and objective insomnia: Some preliminary findings

Daytime performance and alertness were examined in two groups of patients with disorders of initiating and maintaining sleep (DIMS) and a control group of self-described good sleepers. Individuals complaining of disturbed sleep that was verified by polysomnographic indices (objective DIMS) and a group with complaints of disturbed sleep in the absence of objective findings (subjective DIMS) were compared with normal sleepers. Nocturnal polysomnographic recordings documented increased sleep latencies and decreased sleep efficiencies for the objective DIMS group and essentially normal sleep for the subjective DIMS group. However, the subjective DIMS group showed impaired daytime vigilance compared with both the objective DIMS and control groups. Additionally, the subjective DIMS group demonstrated an atypical daytime alertness and a tendency toward lowered arousal during vigilance task performance. Insomniacs without clear objective findings of disturbed sleep, therefore, showed decrements commonly seen following sleep loss or sleep disturbance, whereas insomniacs with evidence of disturbed nocturnal sleep did not differ from the control group in terms of waking function.