Objectives: After age of 65, annually 10 percent of older adults> loss their independent in one or more daily task. Because of decreasing changes in neuromuscular system that is important factor in loss the balance and walking ability in this group of people. In according to these sentences, the aim of this research was to the comparison of mental, physical and mixed practices on static and dynamic balance in health older adults.

Methods & Materials: The study is semi-experimental with pre and post test design and three experimental groups. Statistical sample included 60 older adults> with age range of 60-70 years from Shahre-kord, that randomly divided to three experimental groups. In this research, the Stroke stands test (standing with one leg) were used to measure the static balance and Star Excursion Balance Test (SEBT) test was used to measure the dynamic balance. After 8 session of training, subject of each group participated in post test that similar to pretest. The data were analyzed by one way ANOVA and Tukey post hoc and in order to detect the homogeny of variances, Leaven>s test was used in level of P<0.05.

Results: Statistical results in three training methods (mental, physical and mixed) in static and dynamic balance showed significant difference between groups performance in post test. Further, result of Tukey post hoc show that there is significant difference between mixed group with other groups (P<0.001) and subjects in this group had a better performance than other groups. Furthermore, the performance of physical practice group was better than mental practice group (P<0.029).

Conclusion: according to result of percent study that show improvement in static and dynamic balance in mixed group, it could be concluded that, for increase in muscle strength in lower extremity and promote older adults> balance by strength training, coaches and related affairs can use this training method in their specific programs for older adults.

Objectives: The purpose of this research was to study the effect of eight weeks of resistance training on plasma level of estrogen hormone and body fat percent in sedentary postmenopausal women.

Methods & Materials: Twenty seven sedentary postmenopausal women were purposefully selected as the subjects of this semi-experimental study (mean age 69.52±7.26 years and mean weight of 64.96±7.81 kg). Furtherly,they were randomly divided into experimental (n=13) and control groups (n=14). Fasting blood samples were collected before and after 8 weeks of resistance training. Resistance training was performed at an intensity corresponding to 60-80% of a one-repetition maximum (2 d/wk for 8 weeks). Differences were analyzed by paired t-test and the between group differences by independent t-test.

Results: Comparing differences between the groups indicated that plasma estrogen level significantly increased (P=0.003) and resting heart rate significantly decreased (P=0.010) after eight weeks of resistance training. Body fat percent in experimental group significantly increased in comparing pre and post data (P=0.002).

Conclusion: Postmenopausal women may not need to consume estrogen at all or if applied, use lower doses of such hormonal therapeutic approach if they perform resistance training. Increasing this hormone levels may be attributed to increasing the production of such hormone in fat and other peripheral tissues.

Objectives: Sarcopenia is the decline of muscle mass and strength with age. Evidence suggests that inflammation play important roles in age-related muscle atrophy. The purpose of this study was to investigate the effects of 3 months resistance training on skeletal muscle mass and C-reactive protein levels in elderly men.

Methods & Materials: In this quasi – experimental study with pretest–posttest design, twenty-five middle-age men (age: 64.10±3.40 yr, body mass index: 28.29±2.38 kg/m 2) were randomly assigned to resistance training (n=13) and control (n=12) groups. Resistance training program was performed 50-60 min/d, 3d/wk, for 3 months. Serum C-reactive protein levels and body composition (DEXA) were measured before and after the intervention.

Results: After resistance training, leg press (lower body strength index), bench press (upper body strength index), and skeletal muscle mass were significantly increased (P<0.05), whereas, body fat indices (e.g. body mass index and fat mass) did not change in response to resistance training (P>0.05). Concurrently, C-reactive protein levels were significantly decreased in training group (P<0.05).

Conclusion: Three months resistance training caused an improvement in muscle mass and strength in elderly men, and this improvement were accompanied by decreases in C-reactive protein serum levels.

Objectives: The goal of this study was to compare the effect of 8 weeks aerobic exercise with resistance training on Brain-derived neurotrophic factor level of old men.

Methods & Materials: In this semi-experimental study, a total of 30 elderly men were selected from worldly-wise club of Broujen City, Iran and randomly divided into 3 groups of aerobic training, resistance training, and control (each 10 people). All participants filled the health questionnaire and testimonial. Then, the balance tests and fasting blood was taken. The aerobic and resistance training group trained for 8 weeks, 3 sessions per week, 1 to 1.5 hours in each session. The aerobic training was with 40% to 70% of maximum heart rate and the resistance training was with 45% to 65% of one RM. During of this time, the control group did no training. After 8 weeks, the balance test was administered and blood samples were taken.

Results: Findings were analyzed with test variance analyzing at 0.05. The results showed there was a significant difference between aerobic and resistance training regarding brain-derived neurotrophic factor level (P<0.05). Also, comparison of the 2 kinds of training did not show significant difference in static and dynamic balance (P>0.05).

Conclusion: The results show that both aerobic exercise and resistance increase serum brain-derived neurotrophic factor levels.

Objectives: Balance defects are the leading cause of falls. Fear of falling in elderly tends to have negative impact on their quality of life. Therefore, the aim of the study was to examine the impact of strength and balance training intervention program on the balance performance and quality of life of older adults.
Methods & Materials: The present study was a semi-experimental research with pretest and post-test design. The study was conducted in the Arak city (Iran) and consisted of 31 subjects who were randomly assigned to experiment group (n=15) (mean age=66.07 years old) and control group (n=16) (mean age=70.14 years old).The main variables of the research included quality of life and balance performance, which were measured with an SF-36 questionnaire and one-leg stance with open eyes. The pre-and post-test scores were compared using Student's t-test, and the collected data was analyzed with SPSS software (16-version). 
Results: The findings indicated that balance performance of the experiment group have significantly improved (P=0.05). Moreover, the training intervention program is capable of improving the quality of life (SF.36) subscales. However, no significant differences were noted for social function and role limitation owing to the emotional problems. 
Conclusion: The prevention of fear of fall in elderly necessitates the intervention method for the improvement of their health status as well as maintaining a balance in their daily activities.

Objectives The decline in muscle mass and strength, which are associated with aging, is called sarcopenia. Resistance training is one of the effective methods to deal with sarcopenia. Correspondingly, this study aimed to investigate the effect of 8-week resistance training on muscle mass, strength, and myostatin concentration in old and young men.
Methods & Materials The present study included 14 old men (age range of 55 to 70 years) and 11 young ones (age range of 20 to 35 years) who were randomly chosen from the volunteers. They participated in a progressive resistance training (gradual increase in training load, 50% of one repetition maximum in the first week to 85% in the eighth week) for 8 weeks, 3 days a week. Daily calorie intake, strength, muscle mass, muscle cross-sectional area (by CT scan), and myostatin concentration were measured before and after the training.
Results The findings of the study indicated that after 8 weeks of training, muscle strength significantly increased in the old group in comparison with the young group (P<0.05); however, total muscle mass significantly increased in the young one (P<0.05). Daily calorie intake did not change in both groups (P>0.05). Quadriceps muscle mean (SD) cross-sectional area of the young group (pretest: 76.03[12.21] cm2 compared to posttest: 79.16[11.54] cm2) significantly increased (P<0.05) compared to that in the old group (pretest: 60.03[10.57] cm2 compared to posttest: 61.93[10.43] cm2). The myostatin mean (SD) concentration significantly decreased in both groups (P<0.05), but there was no difference between the groups (3.86[1.89] ng/mL and 3.68[1.66] ng/mL in elderly and young group, respectively; P > 0.05). Also, there was a significant correlation between myostatin concentration with muscle mass in old men (r=0.73, P<0.05).
Conclusion Resistance training was associated with a decline in myostatin level and increase in the muscle mass and cross-sectional area. Hence, the beneficial effect of resistance training may decrease age-related muscle atrophy and affect elderly health.