درخت حوزه‌های تخصصی

Purpose: The purpose of the present research was to investigate the effect of eight weeks of progressive resistance exercise and a subsequent detraining period on the indicators of muscle fiber shortening (FS%) and the relative wall thickness (RWT) of the left ventricle in low-mobility women. Method: This semi-experimental study was conducted in a field-laboratory setting. A total of 32 sedentary women, who met the criteria for participation and were able to engage in the exercise protocol, were randomly assigned to two groups: 1) Resistance training group (16 participants), and 2) Control group (16 participants). Anthropometric characteristics, body composition, and structural indices such as left ventricular muscle fiber shortening percentage (FS%) and relative wall thickness (RWT) were measured using an echocardiography device at three intervals: before the start of training, at the end of 8 weeks of training, and after a 4-week detraining period. The training protocol was implemented over 12 weeks, consisting of 8 weeks of training with three sessions per week, followed by 4 weeks of detraining. Data were analyzed using independent t-tests and repeated measures analysis of variance (ANOVA) at a significance level of p < 0.05, using SPSS version 21. Results: The results showed a significant difference in FS% between pre-test and post-test measurements for both the experimental and control groups (p < 0.05). Additionally, a significant decrease in FS% was observed in the training group during the detraining period (p < 0.05). Similarly, a significant change in RWT was found between pre-test and post-test measurements in both groups (p < 0.05), and significant changes in RWT were also observed during the detraining period in the training group (p < 0.05). Conclusion: Based on these findings, it can be concluded that 8 weeks of resistance training led to beneficial changes in the structure and function of the heart in sedentary women. However, the 4-week detraining period resulted in negative effects on these adaptations. Therefore, it is recommended that individuals engage in regular and structured resistance training to maintain these positive adaptations.

Purpose: Muscle flexibility is a component of physical fitness. Using traditional tools in muscle length evaluation tests creates challenges. Therefore, the use of smartphones and health-related software as an alternative method has become widespread. This study aimed to investigate smartphones' intra- and inter-rater reliability and validity for measuring hamstring muscle length. Method: In a blinded study design, two researchers measured hamstring flexibility through four types of tests on each of the 22 asymptomatic participants with a total of 44 lower limbs. The measurements were compared between the traditional goniometer method and the practical smartphone application method. The intraclass correlation coefficient (ICC) was used to evaluate the reliability of each smartphone measurement, and Bland-Altman analysis was used to check the measurement errors. The validity of the two methods was also investigated. Results: Intra- and inter-rater reliability (ICC≥0.8) were good to almost perfect. In intra-rater reliability, PSLR angle showed consistent imprecision; other tests were free of systematic error and measurement error. The inter-rater reliability revealed a constant error in the right leg's PKE angle. A good to excellent correlation (r = 0.817–0.699) was observed in all the measured values, indicating the two methods' validity. Conclusion: These findings support from intra- and inter-rater reliability and validity of both instruments when measuring hamstring muscle length.

Purpose: In this study, we investigated the effects of resistance training types on clinical and functional indices in older individuals with Osteosarcopenia. Method: In this Systematic Review study, a systematic searching strategy was used in information databases such as Pub Med, Web of Science, Scopus, Google Scholar, Cochrane, and Ambace, all of the studies were extracted by using specific keywords such as Strength exercise, Exercise training, Resistance exercise, Resistance training, Strength training, Physical activity, Osteosarcopenia, Aging, Older adult, Elderly which were published on 7th August 2023. After all preliminary screening, surveying of complete text, and assessment of critical studies, scrutinized articles were related to inclusion criteria. Finally, 17 papers were selected for this study. Results: According to the present study, Resistance training for Osteosarcopenia older individuals has an effective result to improve Osteosarcopenia risk factors, and older patients’ performance and clinical status. However, it has to be mentioned that it needs further study in the contexts of Resistance training and Osteosarcopenia syndrome in elderly adults. Conclusion: Resistance exercise training has markedly beneficial effects on elderly patients with Osteosarcopenia which improves Sarcopenia risk factors, and older patients’ performance, clinical status and function of elderly patients.

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.

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.