Trends in Muscle-Strengthening Exercise Among Nationally Representative Samples of United States Adults Between 2011 and 2017

Background: Muscle-strengthening exercise (MSE) is a component of the World Health Organization's "2010 Global Recommendations on Physical Activity for Health." However, its participation trends are seldom examined in physical activity surveillance. This study describes the prevalence, trends, and correlates of MSE among a large sample of US adults. Methods: The data were analyzed from the 2011, 2013, 2015, and 2017 US Behavioral Risk Factor Surveillance System surveys. Self-reported MSE participation was assessed using the same validated survey item. Population-weighted proportions were calculated for (1) "insufficient" (0-1 time/wk) or (2) "sufficient MSE" (>= 2 times/wk). Prevalence ratios of those reporting sufficient MSE across sociodemographic characteristics were calculated using multivariate Poisson regression. Results: The data were available for 1,735,626 participants (>= 18 y). Over the 7-year monitoring period, the prevalence of sufficient MSE showed a small (1.2%) but statistically significant increase (2011 = 29.1%; 2013 = 29.4%; 2015 = 30.2%; and 2017 = 30.3%, P < .001 for linear trend). Older adults, women, and those with lower education/income were consistently less likely to report sufficient MSE, compared with their counterparts. Conclusions: From 2011 to 2017, between 69.7% and 70.9% of US adults did not meet the MSE guidelines. Consistently low participation levels highlight the need to provide support for uptake of or adherence to MSE at the population level.