نشریه ورزش و علوم زیست حرکتی
سال دهم شماره 1 (پیاپی 19، بهار و تابستان 1397)

Menopausal women face many problems including osteoporosis. One of the preventive ways to avoid osteoporosis and its complications is regular activity and participation in sports. So, the aim of this study was to evaluate the effect of 16 weeks of Pilates exercises on bone mass density in menopausal women.

Therefore, 30 menopausal women were selected as subjects and randomly divided into two groups of control and exercise. The training group practiced Pilates for 16 weeks. T-score, L1-L4 lumbar region and femoral neck of both groups were measured by Stenosis densitometer (DEXA), before training, after 8 weeks and after 16 weeks of training. A comparative test of repeated measurements with intergroup factors was used for examining data.

Results shows that the interaction between time and group is significant (p< 0.05). Bone density of the lumbar vertebra was reduced after 8 weeks of Pilates workouts, which wasn’t significant. But there was a significant increase after 16 weeks of workout compared to 8 weeks (p<0.05). Also, this density ratio shows a significant increase in interaction with the control group after 16 weeks of workout. Similar results were seen in femoral neck density with lumbar vertebrae.

It seems that doing Pilates workouts by menopausal women, has a significant effect on bone mass density after a long time. Therefore training method of Pilates is an appropriate training method for menopausal women.

Exercise through BDNF induces its beneficial effects on the brain. However, its cellular mechanisms are not fully understood. Thus, the purpose of this study was to investigate the effect of 8 weeks interval aerobic training on mRNA expression of SIRT1, CREB and BDNF genes in the hippocampus of male Westar rats.

Twelve 8 week old rats were the subjects of this study rats were randomly divided into two groups: exercise group and control group animals in the exercise group experienced interval aerobic exercise for 8 weeks (5 sessions per week at a speed of 10 to 15 m/min). Forty-eight hours after the last training session, animals were sacrificed and hippocampal tissue was extracted. mRNA expression of SIRT1, CREB and BDNF genes was determined by the real-time PCR method. An independent t-test was used to compare groups and significant differences were considered at the P≤0.05 level.

The results showed that the expression of SIRT1, CREB and BDNF mRNA levels in hippocampal tissue of the exercised group were significantly increased (P ≤0.001).

Overall, it appears that interval aerobic exercise is able to upregulate brain BDNF levels through the SIRT1/CREB/BDNF signaling pathway hence, this type of exercise training can be used to induce the beneficial effects of exercise on brain health.

Diabetic cardiomyopathy refers to changes in the heart as a result of altered glucose homeostasis, leading to ventricular dysfunction, and it is associated with mitochondrial abnormality. Since physical exercise has been known as cardioprotective, the aim of the present study was to investigate the effect of 6 weeks of resistance exercise preconditioning on mitochondrial fusion and fission processes in cardiac tissue of type 2 diabetic rats.

18 male Westar rats were randomly divided into 3 groups: diabetes group (n=6), exercise + diabetes group (n=6) and control group (n=6); The exercise group performed resistance training (Carrying weights with 40 to 160 percent of body weight on the ladder) for 6 weeks and 5 sessions per week. To induce type 2 diabetes, a high-fat diet was administered concurrently with the start of the training program and continued until the end of the study, and 48 hours after the last training session, the injection of STZ was administered intraperitoneally at a dose of 25 mg/kg. Seven days after STZ injection, all rats were dissected and their left ventricular tissue extracted. Real-time-PCR was used to measure the mRNA expression of MFN-2, OPA-1 and Drp-1 genes. Statistical analysis was performed using one-way analysis of variance at a significance level of p ≤ 0.05.

Decreased mRNA expression of MFN-2 and OPA-1 genes and increased mRNA expression of Drp-1 gene were observed in diabetic group animals compared to control ones (p ≥ 0.001). Also, trained diabetic rats showed higher MFN-2 and OPA-1 mRNA expression (p ≥ 0.001), and lower Drp-1 mRNA expression (p ≥ 0.01) compared to the diabetic group.

It seems that 6 weeks of resistance training preconditioning can reduce the risk of diabetic cardiomyopathy through the up-regulation of proteins involved in mitochondrial fusion and down-regulation of enhanced mitochondrial fission in the heart tissue.

Quantifying the relationship between volume and intensity as key components of training is a precise manner that is complicated for most coaches. The aim of this study was to quantify the inverse relationships between training volume and intensity during exhaustive treadmill running among active young men.

32 active young men aged 21 years selected as subjects and completed four exhaustive treadmill running in the four separate phases at 70%, 80%, 90%, and 100% VO2 with at least 72 hours rest intervals. The inverse relationship between regression.

The results showed that the inverse relationship between volume and intensity of exhaustive treadmill running obeys a second-order polynomial regression where the volume of exercise (VE min) is a function of exercise intensity (EI beat/min) (VE min= 0.0225(HR beat/min) 2 – 9.4672 (HR beat/min) +997.91).

It can be concluded that the inverse relationship between volume and intensity of exhaustive treadmill running is non-linear and the fitted equation can be used to predict the volume of exercise based on the exercise intensity among active young men.

Intense exercise damages tissues and disturbs some cellular processes through oxidative stress and antioxidants can modulate intense exercise-induced oxidative stress. The aim of the current study is to examine the effect of short-term selenium on serum hydrogen peroxide (H2O2) and Glutathione (GSH) supplementation of inactive male university students, following a session of acute exhaustive aerobic training.

The present study is a semi-experimental study with a cross-sectional design, which was conducted at the laboratory of the University of Birjand in the year 1397. 10 inactive male university students at the average age of 18.60 ± 0.84 and BMI of 21.38 ± 3.61 ml/kg/min were randomly selected for this research. The 10-member group attended four stages, called control, training, supplementation, and training + supplementation group, in a cross-sectional way. The training protocol which has been used in the test was Bruce Protocol. After attending one training session, the subjects took selenium supplementation in the form of capsules (200 mg daily) for 14 days. Immediately after the training, the blood samples were taken from arm vessels and was analyzed. For the determination of the normal distribution of data, the Shapiro-Wilk test has been employed. Then an analysis of variance repeated measure test and dependent t-test were used for extraction of results at the significant level of p<0.05.

The results showed that following acute exhaustive aerobic training, H2O2 serum levels have increased significantly (p=0.01) and then significantly decreased (p=0.001) by taking selenium supplementation for 14 days (p=0.001); however, after training and selenium supplementation, GSH serum levels did not show any significant changes (p=0.27).

Since taking selenium supplementation for 14 days could significantly decrease the high H2O2 levels, following a session of acute exhaustive aerobic training, it seems that this supplementation can have a positive effect on the oxidative stress, caused by acute training.

The aim of this study was to describe the anthropometric, body composition and physiological profile of elite rowers of Iran and Compare them with selected countries, in order to help sports talent identification nationwide and assess them.

For the purpose, 25 elite Lightweight and Heavyweight rowers (18 males, 7 females) who participated in the 2010 Guangzhou Asian Games, were assessed. Anthropometric profile was measured according to ISAK instruction including height, weight, 5 points girth, 2 points width in addition to sitting height and arm span. Body composition variable measurements were weight, body fat percentage, and BMI. Also, Physiological measurements were aerobic indices (HRVO2max, Pmax, Vo2max) and anaerobic indices (absolute and relative peak power of both upper and lower body). Descriptive statistics were used for describing data and differences between males and females, respectively.

The results of this study indicate that there was a significant difference between light and heavyweight males and females in all variables (anthropometric, body composition and physiological), except HRVO2max in the heavyweight group (P≤0.05).

According to our study, national rowers of Iran are at a higher level of anthropometric indices compared with physiological factors. However, a physiological profile, they have an acceptable condition in comparison with other athletes in selected countries. Accordingly, it seems that with Improvement the quality and quantity of program training in national rowers can increase the number of global medals for country, because it was shown national rowers had a good position in anthropometric and physiological profile.