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  Abstract

  Background and Aim: Sleep is a physiologically important process that has profound effects on the physical and mental health of individuals. With attention to the effects of sleep on mental and physical performance in people, the purpose of this study was to determine the effects of a 30-hour sleep deprivation on reaction time, neuromuscular coordination and aerobic capacity in non-athlete male students.

  Materials and Methods: The present study was a semi-experimental one which used a pretest-posttest design. 18 healthy n on-athlete male students from the University of Gilan (age: 21 ±2 y, height: 174.6±6.5 cm, weight: 71.50±5.50 kg, and body fat: 13±5%) were selected randomly. Seven days before study and after 8 hours of sleep, the subjects performed the reaction time test by reaction time evaluation system, neuromuscular coordination by throwing dart and aerobic capacity by 800-and-1500 meter run. The subjects performed above the items again after one week and after a 30-hour sleep deprivation (6 am to 12 pm the following day). The data were analyzed through dependent t-test using SPSS software Version. 15.

  Results: There were significant differences between pre and post tests in left and right hand reaction times (p<0.05), throw dart scores (p<0.05) and 800 and 1500 meter run (p<0.05).

  Conclusion: Our study indicated that a 30-hour sleep deprivation can cause sloth and a decrease in physical performance. Therefore, athletes and non-athletes should get enough night sleep to prevent the performance decline on activities that need accuracy, coordination and specific attention.

  Keywords: Neuromuscular coordination, physical performance, reaction time, sleep deprivation

 

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Abstract Background and Aim: Endothelial function deteriorates with aging. On the other hand, exercise training improves the function of vascular endothelial cells. Endothelin-1 (ET-1), which is produced by vascular endothelial cells, is a potent constrictor and therefore, has been implicated in regulation of vascular tonus and progression of atherosclerosis. hypothesized that plasma ET-1 concentration increases with age, even in healthy adults, and that lifestyle modification (i.e., exercise) can reduce plasma ET-1 concentration in previously sedentary old adults. Materials and Methods: measured plasma ET-1 concentration in healthy young (21–28 yr old), healthy middle-aged (31–47 yr old), and healthy old (61–69 yr old) women. The plasma level of ET-1 increased significantly with aging (1.02 ± 0.08, 1.33 ± 0.11, and 2.90 ± 0.20 pg/ml in young, middle-aged, and old women, respectively). Thus plasma ET-1 concentration was markedly higher in healthy old women than in healthy young or middle-aged women (by 3- and 2-fold, respectively). In healthy old women, we also measured plasma ET-1 concentration after 3 month of aerobic exercise (cycling on a leg ergometer at 80% of HRR for 30 min, 5 days/wk). Results: Regular exercise significantly decreased plasma ET-1 concentration in the healthy old women (2.22 ± 0.16 pg/ml, P < 0.01) and also significantly reduced their blood pressure. Conclusion :The present study suggests that regular aerobic-endurance exercise reduces plasma ET-1 concentration in old humans, and this reduction in plasma ET-1 concentration may have beneficial effects on the cardiovascular system .

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Aims: The present study intends to study the effect of volunteering exercises during adolescence on testosterone and corticosterone levels in male rats following childhood stress.

Materials &methods: In the present study, 36 male rats were selected as subjects and separated from their mothers from 2 to 14 days for 180 minutes. Then, to determine the experimental and control groups, on the 21st day, these randomly assigned random variables were divided into 3 groups. The groups included control, with stress separated from the mother, a wheel of two rodents. The first group experienced maternal separation from 2 to 14 days, and the control group was kept from the beginning with the mother. The training groups also started volunteering on the 21st birthday. The testosterone and cortisol levels of all groups were measured and the data were statistically analyzed by T and ANOVA methods at a significant level (P< 0.05).

Findings: The results showed that maternal stress severity significantly increased cortisol levels and decreased testosterone levels. On the other hand voluntary exercise, in comparison with the stress group, has increased testosterone levels and significantly reduced cortisol levels.

Conclusion: The results of the study showed that exercise, especially voluntary exercise, during adolescence, reduced stress and decreased depression and anxiety behaviors in adulthood.

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