Prevalence of muscle-strengthening activities in women: the WIN study.

Background: Aerobic and muscle-strengthening activities are related to morbidities and mortality. Resistance exercise/strength training items are included in national surveys, but the manner in which muscle-strengthening activity is queried varies among these surveys.

Purpose: The purpose of this study was to use different self-report measures to examine the prevalence of meeting the 2008 Physical Activity Guidelines for Americans regarding muscle-strengthening activities among women.

Methods: We surveyed 606 community-dwelling women at 4 points in time across a 1.5- to 3-year time period to determine whether the respondents met the national physical activity guidelines for performing muscle-strengthening activities ≥ 2 days per week.

Results: Results were consistent across time but depended on the manner in which the question was asked. If asked to reflect over the past month or a general question about the typical number of days engaged, approximately 40% of women reported engaging in ≥ 2 days per week of resistance exercise/strength training. However, when reports were obtained weekly for 13 weeks, only approximately 18% of respondents met the guidelines.

Conclusion: Results indicate that the timing and nature of questioning can substantially influence the self-reported prevalence of muscle-strengthening physical activities for community-dwelling women.