فصلنامه علوم زیستی ورزشی
پیاپی 13 (تابستان 1391)

Few researches have been performed on the circadian rhythm of oxidants and anti-oxidants and these studies have demonstrated different results. The aim of this study was to investigate the circadian variation of MDA, PC and SOD in non-athlete young men. The research method of this study was semi-experimental. For this purpose, 10 non-athlete active students (mean age: 23.2±2.57 years old, height: 174.5±6.35 cm and weight: 65.9±4.5 kg) from Tabriz University voluntarily participated in this study. All participants performed the protocol of diurnal activity, nocturnal rest, meals and physical activity for two weeks. The day before the blood sampling, all participants were present in the laboratory and spent the night under the supervision of the researcher. The researcher controlled their diurnal activity, nocturnal rest and meals before and during the research for 48 hours. The subjects woke up at 08:00 and slept at midnight with three similar meals served at 08:15, 13:30 and 21:30. Six blood samples (4 cc) were collected from noon for 24 hours with 4-hour intervals. The samples were sent to the laboratory to examine MDA, PC and SOD. Data were analyzed by analysis of variance (ANOVA) with repeated measures. The results showed that MDA exhibited a significant circadian rhythm (P=0.014) while there was not a significant variation in SOD (P=0.089) and PC (P=0.808). But dependent t test showed a significant difference in some hours in SOD factor. The results of this study showed that there is a higher risk of oxidative stress in the morning. So, the stress exercise in the morning should be performed with higher attention.

Parathyroid hormone (PTH) is the major factor of calcium homeostasis. This hormone increases calcium uptake in intestines through stimulation of the active formation of vitamin D and eventually increases bone density. The aim of this study was to investigate the effect of one session of resistance and endurance activity on PTH and ALP in untrained young girls (mean age 21.9±1.23 yrs, height 161.95±2.7 cm and weight 63.15±6.9 Kg). For this purpose, 30 young female university students (20-25 years old) were selected and divided randomly into three groups: endurance, resistance and control. Exercise protocol in endurance group included running on a treadmill and for 45 minutes with 45% VO2max and in resistance group included front arm, front leg and Scott; each of them were performed in three sets with 55,65,75% of 1RM during 45 minutes. Blood samples were collected in three stages (baseline, 15 minutes and 24 hours after the protocol). The data were analyzed via one-way analysis of variance with repeated measures, and post hoc LSD test at P≤0.05. Results showed that the exercise increased PTH and ALP in resistance and endurance group; this increase was slightly higher after resistance exercise than endurance exercise but there was no significant difference between the two groups. The present research showed that one session of resistance and endurance activity significantly increased PTH and ALP in untrained young female.

One of the important changes of sport and physical activity in human beings is hormonal changes; these changes have different effects based on intensity, duration and type of training. Beta endorphin (BE), one of the neural system hormones, shows changes in blood plasma level by exercise. This neuropeptide plays an important role in pain relieving, well-being, mood enhancing and euphoria. The aim of this research was to compare the effect of one session of aerobic and anaerobic training on plasma beta endorphin changes in active and sedentary girls. After distributing the physical activity questionnaire in Alzahra University, 12 physical education students as active group and 12 non-physical education students as sedentary group were selected. Bruce and Rast tests as aerobic and aerobic tests were applied. Beta-endorphin concentration was determined before and after the tests. t test and ANCOVA were used to analyze data. The results showed that plasma BE level increased in both active and sedentary groups after aerobic training. Also, BE level increased after anaerobic training in both groups. No significant difference was observed in BE between the two groups after both aerobic and anaerobic training. No difference was observed between aerobic and anaerobic training in subjects. No difference was observed in both types of training between the two groups.

The aim of the present study was to investigate the effect of two aerobic training programs with different intensities on some cardiovascular risk factors in young girls. For this purpose, 42 girls (mean age 20.59±1.46 years, height 160.29±4.75 cm, weight 59.23±8.82 Kg, BMI 22.08±3.41 kg/m2, %BF 15.42±3.85 and Vo2max 25.34±3.96 ml/kg/min) were voluntarily participated in this study and divided into three groups randomly: aerobic training (intensity 65-75% maximal heart rate), aerobic training (intensity 80-90% maximal heart rate) and control group. Then, two experimental groups performed aerobic training three sessions per week for 8 weeks. One-way ANOVA showed no significant differences among the three groups in total cholesterol, triglyceride, LDL-C, HDL, HDL2, HDL3 and apoA-1 (P>0.05). Moreover, the results indicated that aerobic training with both 65-75% maximal heart rate and 80-90% maximal heart rate significantly increased VO2max in young girls (P<0.05). This study showed that aerobic training with two mentioned intensities had no significant effect on cardiovascular risk factors in healthy young girls, but in it can improve aerobic fitness in these volunteers.

The aim of this research was to study the effect of eight weeks of selected aerobic exercises on depression and serum serotonin concentration in depressed female university students aged between 18 and 25 in Aligudarz city. For this purpose, using Beck depression questionnaire, 20 female students with moderate depression were selected in two groups (experimental n = 10 and control n=10). To evaluate the impact aerobics Selected the concentration of serotonin in plasma, In order to investigate the effect of selected aerobic exercise on the concentration of plasma serotonin, the experimental group performed aerobic running for eight weeks (3 sessions per week) with 60-65% HRmax. The research variables were measured 24 hours before the first and 96 hours after the last session. The student t test and ANOVA were used to analyze data at P<0.05. Results showed that plasma serotonin level increased 50% in the experimental group although this increase was not statistically significant. Depression significantly decreased in experimental group compared to control group. Also, there was a significant relationship between increased serotonin and decreased depression. It can be concluded that selected aerobic exercise significantly decreased depression and increased concentrations of serotonin and proper physical activity can effectively treat depression.

Hemorheology specialists believe that athletes of different sport fields have different hemorheological patterns. The aim of this study was to investigate the effect of sport field on hemorheological variables following acute aerobic exercise. Athletes were divided into three groups of 15 subjects (endurance runners: mean±SD: age 24.6±5.2 yr, BF% 6.8±1.6, BMI 21±1; football players: age 22.5±1.7 yr, BF% 7.61±1.6, BMI 22.3±1.4; karate players: age 23.1±3.5 yr, BF% 8.23±3.1, BMI 23.7±2.4) performed 30-min. exercise on a cycle ergometer at 85% maximal heart rate. Blood samples were collected before, immediately after the exercise and 30 min. after the recovery. Independent one-way ANOVA was used to investigate the effect of sport field on hemorheological parameters and analysis of variance with repeated measures was used to investigate the effect of exercise and recovery on hemorheological parameters. Significant differences in plasma and blood viscosity were observed following the exercise and recovery (p<0.05) and karate players had the highest viscosity. Plasma and blood viscosity increased after the exercise and decreased after the recovery.

The aim of this study was to investigate the effect of endurance, resistance and concurrent training on plasma leptin levels of male students. For this purpose, 48 male university students (mean age 21.45 years) participated in this study. Subjects were randomly assigned to three exercise groups: endurance group (n=12), resistance group (n=12) and concurrent group (n=12) and a control group (n=12). Their height, weight, fat percentage, BMI and VO2max were determined. The endurance group received endurance training for 8 weeks, 3 sessions per week with an intensity of 75-85% maximal heart rate. Also, in resistance training group, 100% power of subjects was determined. Then, during exercise sessions, a percentage of maximum power was prescribed for them. Concurrent group received both endurance and resistance training programs in one day. In order to compare pretest and posttest results, paired t test and ANOVA was used. The results showed that all three methods of endurance, resistance and concurrent training significantly decreased plasma leptin levels (P=0.982). There was no significant difference in the effects of endurance, resistance and concurrent training on plasma leptin changes. It can be concluded that regular physical activity (any type of endurance, resistance or concurrent training with a negative energy balance) can decrease leptin levels.

This study intended to compare the effect of consuming creatine and mixed creatine-carbohydrate supplementations on the anaerobic power and cellular damage indices (CK, LDH) in males aged between 15 and 18 in the city of Kouhrang. For this purpose, 36 subjects (mean age 16.42±0.90 yrs, weight 54.85±9.96 kg, and height 167.75±8.28 cm) were selected by available method. First, blood samples were collected to determine the baseline of creatine kinase and lactate dehydrogenase as cellular damage indices. Then, anaerobic power tests (Sergeant Jump, pair jump, medical ball throw, and dash) were performed. Next, the subjects were randomly divided into three 12-subject groups. The first experimental group consumed only carbohydrate; the second experimental group received creatine; and the third experimental group consumed a mixture of creatine and carbohydrate. Field practice was comprised of three sessions of weight training together with consumption of creatine and carbohydrate supplements for five days. Supplements, dissolved in water, were consumed four times a day: after breakfast, lunch, afternoon tea, and dinner. Then, immediately after the last day of practice, the blood samples were collected to measure the level of the above-mentioned enzymes. Two days later, anaerobic tests were administered once again to determine the effect of supplements. Descriptive and inferential statistics (one-way analysis of variance, Tokey post hoc test) and SPSS ver. 16 were used to analyze the data. The results showed that creatine improved the anaerobic power in the second experimental group (P<0.05). Moreover, this supplement significantly increased the level of creatine kinase and lactate dehydrogenase in this group (P<0.05). In the group who consumed carbohydrate besides creatine, anaerobic power significantly increased (P<0.001) while CK and LDH did not significantly increase. In carbohydrate group, no significant difference was observed in anaerobic power and CK and LDH levels. These findings indicated that creatine causes cellular damage and significantly increases creatine kinase and lactate dehydrogenase despite the positive effects on the anaerobic power while the mixture of creatine and carbohydrate increases anaerobic power and prevents cellular damage. Thus, it is recommended that athletes consume creatine along with carbohydrate to suffer fewer problems