نشریه ورزش و علوم زیست حرکتی
سال سوم شماره 1 (پیاپی 5، بهار و تابستان 1390)

Although exercise training induces significant physiologic variations in immune system, the effect of environmental and physical stress in hot environment and subsequent altering hydration status on some of the physiological and humoral immune system indices is not that much clear. The aim of this study was to investigate physiological and immune system responses followed by altering hydration status in Greco-Romance wrestlers. 14 healthy young men were assigned to experimental and control groups randomly. The experimental group lost 3-4% of their body weight in dry sauna through 10-min intermittence. Urine and blood samples were taken in three stages, before, immediately and after 18 hr of sauna. Arm cranking test in a 6 min high intensity program with 8×15s intervals at maximum work load and 30 s active recoveries followed by each high intensity bout in all 3 trials was given. Result showed significant increase in Leucocytes-, lymphocyte-, monocyte-, neutrophil-counting at dehydration trial in the experimental group. Haemoglobin counting in theexperimental group increased and decreased 5 and 7 percent followed by dehydration and rehydration successively. Hematocrit increased 2.74% by dehydration and decreased 2.24% by rehydration. Fibrinogen increased significantly after dehydration compared to the control group.Discussion and loss of body weight through sauna and exercise training in hot and humid environment can induce unfavorable variation in physiologic and humoral immune system indices and can affect people's health. Hence, rehydration is essentially recommend to all people who are enjoying exercise training in order to favor its health effects.

In recent decades, various methods have been used to improve power and explosive strength of lower extremities in volleyball players which results in higher jumping. The purpose of this study was to investigate whole body vibration and plyometric training effects on vertical height jumping in young male volleyball players. Twenty young volleyball players of Peikan club in Tehran were selected and randomly divided into two equal groups: vibration group (going through a four-weekprogram) and plyometric group (experiencing an eight-week program). Sarjent test was used to evaluate the jumping rate of the players. To determine internal differences existing betweenand within the groups, the data were analyzed through paired and independent t tests, respectively. Data analysis indicated that conducting eight weeks plyometric and four weeks vibration trainings increases jumping rate in young volleyball players significantly (P<0.0001). Also, t test results revealed that there were no significant differences in mean jumping rate between two groups (P>0.05).Discussion and Based on our results, it seems that, in comparison to other training procedures, whole body vibration training, as a new training approach, can enhance power and explosive strength of lower extremities and improve jumping rate in volleyball players in a short period.

Adipose tissue is an active organ that controls the regulation of systemic and metabolic responses through semihormone secretions, specifically adipokines. The aim of the present research was to evaluate the effect of 12 weeks combined exercise training (enduranceresistance) on changing the plasma Chemerin, Vaspin, Visfatin, and sensitivity insulin among overweight females. Thirty sedentary students of Hakim Sabzevari University volunteered for this study. Their BMI range was 27-30. Then, they were divided randomly into two groups of experimental (combined exercise) and control groups. Fasting blood samples of all subjects following 12 hr. were taken 24 hr. before and 48 hr. after the last exercise session. The combined group participated in 12 weeks of combined training (two days of interval endurance exercise and two days of resistance exercise). Intensity of endurance exercise was 60-80% at HR max and resistance exercise 60-80% 1RM consisting of seven stations (3 sets for 8-12 times) (biceps M, triceps M, posterior-superior trunk M, inferior abdominal M, quadriceps femoral M, hip M, hamstring M). Independent t- test was used to determine any significant differences between posttest of the experimental and control groups and paired t- test to evaluate average differencesbetween pre- and posttest in the two groups. Findings showed a significant improvement between weight, WHR (p=0,014), body fat Percent (p=0,017), and a significant reduction in Vaspin (p=0,50), Visfatin (0,012),TG(p=0,035), and a significant increase in GH (0,006), HDL (p=0,024), in comparison with the control group. However, the reduction between Chemerin (p=0,065), LDL (p=0,79), insulin(p=0,91), glucose(p=0,98) and insulin sensitivity (p=0,398) was not significant.Discussion and The results showed that 12 weeks of combined exercise training could lead to a significant reduction in vaspin and visfatin and a significant increase in GH and an improvement in some lipid profiles.

Moderate and high-intensity exercise is a potent stimulus for growth hormone (GH) and cortisol secretion. Other factors such as circadian rhythms can also modulate the GH and cortisol responses to exercise. The purpose of this study was to determine the effects of daily exercise time on GH and cortisol response to exercise. 22 female university students (the mean age: 21.59±2.24 years, BMI: 21.05±2.75 kg/m2, body fat percent: 27.28±3.20 %) were randomly divided into experimental group (n=12) and control group (n=10). Subjects performed Bruce Protocol Stress Test on treadmill after 12 hours of fasting on two separate days. The first test was performed at 7:00 AM and the second one was conducted at 6:00 PM. Blood samples (10cc) were collected at both stages, immediately before and after exercise. The results of inter-group ANOVA and post-hoc test of Tukey showed a significant increase in the mean of serum GH after exercise in the morning and evening (p=0.001). The mean of serum cortisol had noticeably risen after exercise in the morning (p<0.05). A significant increase was also observed in GH/cortisole ratio after exercise in the evening (p<0.001).Discussion and With respect to the increase in plasma GH/cortisole ratio in the evening, it seems there exist better anabolism conditions in the body in the evening exercise.

Diabetes is a metabolic disorder that is caused by a decline in insulin secretion or insulin resistance. Omentin -1 is a recently discovered protein that is expressed in visceral adipose tissue and secreted and increases insulin sensitivity. The aim of present study was to investigate the effect of an aerobic exercise session on plasma omentin -1. In this study, diabetes was induced by streptozotocin (50 mg/kg) injection in a single dose in mice. 40 male Wistar rats with average weight of 165 ±5 g were randomly divided into a control group and three exercise groups. The training group ran a session with a speed of 20 meters per minute for 50 minutes on the treadmill. Mice were anesthetized inseparated groups, immediately, 4 hr after exercise and 24 hr after exercise and sampling was done. Finally, plasma levels of omentin were determined by ELISA. The results indicate that plasma levels of omentin-1 did not have any significant changes in all training groups compared with the control group.Discussion and It is likely that omentin-1 plasma levels increase after an exercise session in diabetic rats may have an anti-inflammatory effect.

Omega-3 fatty acid supplementation is unsaturated fatty acid that is associated with increased expression of adiponectin in fat tissues. The aim of present studywas to investigate the effects of omega-3 fatty acid supplementation along with and aerobic exercise on adiponectin and insulin resistance of elderly women. 37 healthy older women aged 55-80 years who volunteered for this study were randomly divided into three groups: aerobic training (12=n), aerobic exercises alongwith omega-3 fatty acid supplements (13 = n) and control group (12 =n) respectively. Rhythmic low-impact aerobic exercises with 40 percent maximum heart rate were performed 8 weeks, threesessions per week. The duration of exercise program was as 20 min. in first week, 35 min. in second week and 45 min. in week 3 and 4 and 60 min. in weeks 5, 6, 7 and 8. Supplement groupreceived 3 g omega-3 capsules per day. Adiponectin and Insulin concentration were measured by ELISA method and specific kit. Insulin resistance was calculated by using the homeostatic modelassessment equation (HOMA IR) for insulin resistance. Dependent t-test and One-way analysis variance were used for the measurement of changes within each group and between groups, respectively. Weight and BMI significantly decreased in both exercise and supplementation group but only significantly decreased in exercise and supplement group. Also, adiponectin significantly increased within both groups (exercise groups: P=0.03 and exercises and supplements groups: p = 0.001), but no significant difference was observed between groups at posttest. Insulinresistance was not significantly different not within nor between groups.Discussion and Overall, it appears that aerobic exercises training, along with omega-3 fatty acid supplementation, have positive effects on adiponectin and insulin resistance of older women.

Intensive exercise based on its nature, characterized by an acute state of negative energy balance. However, heavy exercise may actually result in a prolonged negative energy balance for its neuro-endocrine changes. Ghrelin is a peptide secreted by the stomach and plays an important role in energy balance, obesity and food intake behavior. This hormone acts as an appetite stimulator and body gain. The purpose of this study is to determine the acute response of plasma total ghrelin levels to one session circuit resistance exercise in high carbohydrate meal and fasted states in healthy young men. Forty male college students (age=22.10±1.08 years, height= 173.55±5.03 cm, weight= 65.24±7.63 kg and body mass index 21.02±0.33 kg/m2 (Mean±SD)) were randomly assigned to the two experimental and two control groups. Circulating levels of total plasma ghrelin, growth hormone, glucose and insulin of subjects were measured before and immediately after exercise protocol. Results of Two Way ANOVA test showed that one session circuit resistance exercise at %80 of repetition maximum with high carbohydrate meal and fasted status has no significantly effects on total plasma ghrelin, growth hormone and insulin (p>0.05) and glucose showed a significant increase in both fasting and feeding with high carbohydrate meal states (p<0.05). It seems that the reason of increased plasma glucose levels was the increase of liver glycogenolysis that lead to suppressed effect of glucose and no significant increase plasma ghrelin levels; However, the total ghrelin sub-fractions may have changed. Despite the improvement in exercise performance after high carbohydrate diet, it is likely that nochange in plasma Ghrelin level after resistance activity, not hungry or the food intake, after stimulation of the activity and subsequent reserves to compensate for lost of energy.

In order to enhance our knowledge of relationship between exercise, appetite, and obesity, the present study attempted to assess the effect of 12 endurance training weeks on body weight, food intake, and Nesfatin-1 in obese male rats. Sixteen obese male wistar rats (2 month old) were fed for 8 weeks on a high fat diet, reaching an average weight of 319±30 g. The rats were divided into control (n=8) and training (n=8) groups. The training group was given exercise on motor-driven treadmill at 30 m/min (0٪ grade), 60 min/day, 5 days/week for 12 weeks, and both groups were given ‘‘ad libitum’’. The ELISA method was used for laboratory analysis of Nesfatin-1, insulin and glucose, and repeated measure ANOVA and independent T test were used to analyze the data. The results revealed that the weight of training group was significantly lower than control group (p=0001). In the first four weeks, food intake of the training group decreasedsignificantly (p=0001), but it converged to control group during the next weeks. Nesfatin-1 plasma level was high in training group (p=0001). The levels of Glucose and insulin were considerably low in the training group (p=0001). Discussion and Based on the findings of this study, endurance training prevents the weight gain and a decrease in food intake may be one of the important factors. Probably, increasing in the level of anti-appetite nesfatin-1 plays a key role in this mechanism, and it is necessary to look closer and more precisely to this mechanism in future studies.

Angiogenesis is the formation of new blood vessels from an existing vascular bed. This process can facilitate the oxygen delivery to active muscles. Studies have shown that acute exercise can affect the process of angiogenesis. However, the role of the type of contraction that is used in exercise, especially eccentric contraction, in angiogenesis process is not yet clear. The aim of this study was to investigate the effect of eccentric exercise on serum levels of vascular endothelial growth factor (VEGF) and Endostatin in male wistar rats. 36 male wistar rats (age= 49±7, weight=290±10) were used in this study. The rats were divided into two groups: the experimental group (eccentric exercise group) (n = 24) and the control group (n = 12). Also, the experiment group was subdivided immediately after the exercise (n = 12) and 24 hours after the exercise (n = 12). The eccentric exercise involved running on a treadmill with the speed of 20 m/s and -160 slopes for 45 minutes. Immediately and 24 hours after the exercise, blood sample was drawn from the descending aortafor measurement of serum VEGF and endostatin. Serum VEGF and endostatin were measured by ELISA method. Results of the study showed that immediately and 24 hours after the exercise the serum levels of VEGF decreased 28% and 12%, respectively (pı0.05) Also, serum levels ofendostatin decreased 26% and 38%, immediately and 24 hours after the exercise, respectively (pı0.05). Additionally, VEGF/endostatin ratio decreased immediately after the exercise (p=0.02) and increased significantly 24 hours after the exercise (p=0.001).Discussion and The finding of this study showed that the main factors that are involved in angiogenesis decreased significantly immediately after the eccentric exercise This finding may provide new insights into better comprehension of mechanisms related to changes of capillary density in response to eccentric training.