درخت حوزه‌های تخصصی

Purpose: Delayed onset muscle soreness (DOMS) is pain and stiffness that occurs several hours to several days after unusual or intense exercise. It is thought that this exercise causes small damage (micro trauma) to muscle fibers. The aim of the present study was to compare the effects of high-intensity resistance training and resistance retraining on serum levels of some indices of muscle damage in inactive young girls. Method: Twenty-four healthy inactive young girls voluntarily participated in the present study. They then randomly divided into two groups of 10. The muscle injury protocol included five stations of biceps and shoulder presses with a barbell, squats, chest press, and leg press. Each movement consisted of three sets of 8 to 12 repetitions, with an intensity of 75% of one repetition maximum. Serum levels of creatine kinase, lactate dehydrogenase, and aspartate aminotransferase enzymes were measured before the activity and at intervals of 1, 26, and 48 hours after it. Analysis of variance with repeated measures and independent t-test were used to analyze the data at a significance level of p≥0.05. Results: there was no significant difference in the changes in creatine kinase, lactate dehydrogenase, and aspartate aminotransferase between the two groups at different stages of measurement after retraining (p<0.05). Conclusion: According to the results of the present study, it can be concluded that resistance training cannot be a significant influencing variable on the amount of muscle damage. However, more research in this field is needed.

Background and purpose: Physical activity is effective on the serum level of the monoamine neurotransmitter dopamine and also reduces psychological disorders such as depression. The aim of this study was to investigate the effect of eight weeks of walking on plasma levels of dopamine and the level of depression in elderly women with Alzheimer's disease. Method: In this semi-experimental study, 20 women with Alzheimer's disease with an average age of 73.5 ± 7.72 years who were suffering from moderate to severe depression according to the Beck questionnaire with the opinion of a psychiatrist in a targeted manner and the sample available for were selected to participate in the research. The subjects were randomly divided into two equal groups of 10 people, including the experimental group (walking) and the control group (without regular physical activity). The subjects in the walking group exercised on the treadmill for eight weeks three sessions per week and each session lasted 30-45 minutes with an intensity of 60-75% of the maximum heart rate. Before and after the exercise intervention, blood samples were taken from the cubital vein of all participants in a 12-hour fasting state. Serotonin and dopamine levels were evaluated by ELISA method. The results were extracted using the paired t test and covariance at a significance level of 0.5. Findings: 8 weeks of walking led to a significant increase in dopamine levels (p=0.005) and a significant decrease in depression (p=0.001) in the experimental group compared to the control group. Conclusion: It seems that walking can have positive effects on some neurotransmitters and reduce the level of depression in elderly women with Alzheimer's disease.

Background: Osteoporosis is a decrease in bone density among older adults that can lead to painful fractures and disability. People in developing countries are not interested in examining bone mineral density until fractures occur. Therefore, the aim of this study was to investigate the relationship between the indicators affecting osteoporosis with femoral mineral density in active and inactive elderly men.Methods: A total of 45 active and 45 inactive men with an age range of 70 to 85 years with medical records and clinical trials were selected. Anthropometric characteristics and serum indices of the subjects were used as effective indicators of osteoporosis. Pearson correlation coefficient was used to find the relationship between the indicators and the mineral density of the femur. SPSS software version 26 was used for data analysis.Results: The results of the present study showed that in both groups of active and inactive elderly men, a significant relationship was observed between anthropometric characteristics and serum indices with bone mineral density (P≤0.05). No significant relationship was found between other indicators.Conclusion: In general, the results show that there is a significant relationship between bone density and weight, body mass index, age, calcium, phosphorus and serum alkaline phosphatase of all subjects. Therefore, in adulthood and old age, these blood and anthropometric variables can be used to identify people at risk for osteoporosis.