Search PubMed⌕ Search

Biomedical subjects

J Trinder

Publications and source records attributed to J Trinder.

52 records · Page 3Linked to original sources
PubMed1988

Physical exercise and sleep: the effect of the age and sex of the subjects and type of exercise.

Exercise has generally been held to result in an increase in slow wave sleep (SWS) and sleep duration. We report the results of three experiments which assessed the effects of exercise on the sleep of young fit women as compared to young fit men; fit older men (aged 41 years) as compared to fit younger men (aged 22 years); and the effects of power exercise on the sleep of a group of trained power lifters. In each experiment physically fit subjects had their sleep assessed following both late afternoon exercise and no exercise conditions. In none of the experiments did exercise result in an increase in SWS or sleep duration. Instead the tendency was for exercise to affect sleep adversely.

Adult↗
PubMed1987

Ventilation during sleep onset.

There is now considerable evidence which indicates that respiratory activity is different during sleep compared with wakefulness. However, there has been little work on respiratory changes during the transitional period from wakefulness to sleep. The present study was concerned with the quantitative and temporal properties of ventilation during sleep onset. Sleep onsets were studied in five young male adults in a series of single-subject designs in which sleep onsets were replications. The results indicated that during sleep onset the loss of alpha-activity in the electroencephalogram was associated with a substantial, rapid, and highly predictable reduction in ventilation. The change in ventilation was typically due to a reduction in tidal volume and was, in part, secondary to a reduction in metabolic rate. We speculate that the nonmetabolic component may reflect the loss of waking neural drive to respiration, though the present study did not eliminate a variety of other interpretations.

Adult↗
PubMed1984

Fitness facilitates sleep.

Eight army recruits were studied at the start, middle, and end of their initial 18-week training programme. At each point the subjects were studied for four consecutive nights in the sleep laboratory. Their sleep was characterized by the means of the recordings on the last two nights. Within 2 days of the sleep recordings (but never on the same day) each subject spent 2 non-consecutive days in the exercise laboratory. On the 1st day a maximum oxygen consumption (VO2 max) measurement was performed on a treadmill and on the 2nd day a 24-min progressive exercise bicycle ergometer test was carried out with simultaneous venous sampling (for lactic acid measurements) and oxygen consumption recordings from which the lactate turn point (LTP) was calculated. LTP was used as a measure of fitness. Approximately 1 week after the above measures lean muscle mass as calculated by total body potassium estimation was obtained for each subject. Slow wave sleep (SWS) as a percentage of total sleep time increased significantly between the start and the measurements at 9 and 18 weeks, being 21.9%, 29.9%, and 28.5% respectively. Anaerobic threshold increased significantly (P less than 0.05) over the first 9 weeks and continued to increase to the end of the training period (P less than 0.001) using VO2 when lactate level was 2 mmol/l as a percentage of VO2 max. With increase in fitness, sleep onset latency and wake time during sleep decreased and sleep efficiency improved. The results suggest that as fitness increases sleep quality improves.

Adolescent↗
PubMed1984

Effect of physical fitness and body composition on sleep and sleep-related hormone concentrations.

The study assessed the effect of physical fitness and body composition on sleep and the nighttime secretion of the hormones, human growth hormone (hGH), prolactin, and cortisol. Two groups of 17 subjects, one of fit athletes and the other of unfit nonathletes, were selected so that the groups were matched for weight, height, lean body mass (LBM), and fat levels. Subjects slept in a sleep laboratory for 3 nonconsecutive nights: 1 adaptation night and 2 experimental nights. On 1 experimental night blood samples were collected; on the other, baseline sleep was assessed and the catheter was not inserted. Weight and height were measured and LBM assessed by 24 h urinary creatinine. The effect of physical fitness was tested by a comparison of the two groups; body composition was assessed by correlation analyses. Physical fitness did not have a significant effect on either sleep or hormone levels, although in the latter case the results were marginal. In contrast, body composition was related to both sleep and hGH. Percentage LBM was negatively correlated with slow-wave sleep and positively correlated with hGH levels. These results were significant for all subjects combined and for the fit group, although not the unfit group alone.

Adipose Tissue↗
PubMed1982

Energy expenditure and total sleep time: effect of physical exercise.

The energy conservation model proposes that the main function of sleep is to lower metabolic requirements periodically and thus to conserve energy. However, certain variations in energy expenditure, such as that produced by physical exercise, have not been found to be consistently related to sleep length. We hypothesized that, because sleep variables may adapt relatively slowly to metabolic changes, the effect of exercise on sleep time would be observed as a function of habitual exercise patterns, not of daily variations. The study consisted of a retrospective analysis of five experiments. Although the design of each experiment was idiosyncratic, all involved physically fit and/or unfit subjects whose sleep was assessed following daytime exercise and/or no exercise conditions. As predicted, fit subjects slept significantly longer than unfit subjects, and daytime exercise had no consistent effect on sleep duration. However, for several reasons, the relevance of the data to the energy conservation model is uncertain.

Adult↗
PubMed1971

Dream recall.

Explore the source record for details and available documents.

Circadian Rhythm↗