Relations of meeting national public health recommendations for muscular strengthening activities with strength, body composition, and obesity: the women's injury study

Objectives.We examined the relations of meeting or notmeeting the 2008 Physical Activity Guidelines for Americans recommendations for muscular strengthening activities with percentage of body fat, body mass index (BMI; defined as weight in kilograms divided by height in meters, squared), muscular strength, and obesity classification in women. Methods. We analyzed data on 918 women aged 20 to 83 years in Injury Study from 2007 to 2009. A baseline orthopedic examination measurement of height, body weight, skinfolds, and muscle strength. Results. Women who met muscle strengthening activity recommendations had significantly lower BMI and percentage of body fat and higher muscle strength. Women not meeting those recommendations were more likely to be obese (BMI≥30) compared with women who met the recommendations after we adjusted for age, race, and aerobic physical activity (odds ratio=2.28; 95% confidence interval=1.61, 3.23). Conclusions. There was a small but significant positive association between meeting muscle strengthening activity recommendations and muscular strength, a moderate inverse association with body fat percentage, and a strong inverse associationwith obesity classification, providing preliminary support for themuscle strengthening activity recommendation for women.