Effect of strength training and short-term detraining on muscle mass in women aged over 50 years old

The loss of muscle mass is associated with aging. The aim of this study was to determine the effects of resistance training and detraining on muscle mass in elderly women. Twenty post-menopausal women aged >/= 50 years old were enrolled. Matching for age, they were randomly assigned into control and resistance training group [RT]. The intervention consisted of three sets of 10 repetitions for 10 movements with Thera-Band tubing [based on 80-100% 10-RM], three times a week, for 12 weeks and thereafter, four weeks detraining. Skinfold thickness was determined by caliper. Percentage of body fat was estimated from skinfold thickness [triceps and subscapular] by McArdle method. Fat mass [FM] and fat-free mass [FFM] were calculated. Range of motion for trunk flexion and extension was determined. During 12 weeks of intervention, significant increases were observed in 1-RM of biceps curl, FFM, trunk flexion and extension and significant decreases during four weeks detraining in RT group. The RT group demonstrated significant decreases during resistance training and increases during detraining in skinfold thickness. FFM, trunk flexion, and extension decreased and skinfold thickness,%FM, and weight of body fat increased in the control group [P < 0.05]. Resistance training with Thera-Band enhanced strength and muscle endurance in elderly women and a 4-week detraining period had an adverse effect on muscle power. This suggests that a strength training program is an effective intervention to prevent functional reductions, and can contribute to improve neuromuscular function in older adults

Association between physical activity and metabolic risk factors in adolescents: Tehran lipid and glucose study

Physical activity [PA] is associated with the metabolic syndrome [MetS] and its components. This study aimed to examine the association between PA and MetS and its components among normal weight and overweight/obese adolescent in Tehran Lipid and Glucose Study [TLGS]. This cross-sectional study includes 777 adolescents, aged 12-18 years, who were selected by multi-stage random cluster sampling from among TLGS participants. Subjects were classified as normal weight and overweight/obese based on the age- and sex-specific standardized percentile curves of BMI for Iranian population. Levels of PA were assessed using a standardized and modifiable activity questionnaire [MAQ], and categorized into tertiles. MetS was defined according to the Cook's criteria. Prevalence of the MetS was higher in overweight/obese than normal group [35% vs. 3%; P: 0.02]. Normal groups were more physically active [50% vs. 44%]; however, difference was not significant. There was a significant association between the light PA and risk of lower level of HDL-C before and after adjustment, in normal weight group [OR: 1.62, CI 95%: 1.11, 2.35; OR: 1.65, CI 95%: 1.12, 2.44, respectively]. The overweight/obese group with light and moderate PA had a higher risk of having abdominal obesity than those with vigorous PA, only after adjustment for determined covariates [OR: 1.11, CI 95%: 1.07, 1.21; OR: 1.06, CI 95%: 1.01, 1.08, respectively]; the association between MetS and PA was not significant. The results of this study confirm the association between PA and some individual components of MetS such as waist and HDL-C

Reliability and validity of the modifiable activity questionnaire [MAQ] in an Iranian urban adult population

Background: The purpose of this study is to evaluate the validity and reliability of a Persian translation of the Modifiable Activity Questionnaire [MAQ] in a sample of adults from Tehran, Iran

Methods: There were 48 adults [53.1% males] enrolled to test the physical activity questionnaire. A sub-sample included 33 participants [45.5% males] who assessed the reliability of the physical activity questionnaire. The validity was tested in 25 individuals [48.0% males]. The reliability of two MAQs was calculated by intraclass correlation coefficients. The validation study was evaluated with the Spearman correlation coefficients to compare data between the means of 2 MAQs and the means of 4 physical activity records

Results: Intraclass correlation coefficients between 2 MAQs for the previous year's leisure time was 0.94; for occupational, it was 0.98; and for total [leisure and occupational combined] physical activity, it was 0.97. The Spearman correlation coefficients between the means of the 2 MAQs and means of the 4 physical activity records was 0.39 [P=0.05] for leisure time, 0.36 [P=0.07] for occupational, and 0.47 [P=0.01] for total [leisure and occupational combined] physical activities

Conclusions: High reliability and relatively moderate validity were found for the Persian translated MAQ in adults from Tehran. However, further studies with larger sample sizes are suggested to more precisely assess the validity of the MAQ