In a first of its kind study in the American Journal of Preventive Medicine1, data from a nationally representative sample of US adults were used by investigators to link low-to-moderately frequent muscle-strengthening exercise (MSE) with fewer reported health conditions such as diabetes, obesity, and cancer.
"This study is among the first to show that most US adults do not engage in MSE. We also demonstrate that as few as one or two MSE sessions a week result in fewer reported health conditions such as diabetes, obesity, and cancer, even after accounting for aerobic exercise levels," explained lead investigator Jason A. Bennie, PhD, Physically Active Lifestyles Research Group (USQ PALs), Institute for Resilient Regions, University of Southern Queensland, Springfield, QLD, Australia.
The assessment of the weekly frequency of MSE among US adults was based on an analysis of data on more than 397,000 participants (18-80 years old) in the 2015 Behavioral Risk Factor Surveillance System (BRFSS). Over 30 percent met the MSE recommendations (two or more times per week), while approximately 58 percent reported no MSE activity at all, which was more than twice as many respondents who reported no aerobic exercise (24.6 percent).
BRFSS was initiated in 1984 to collect state-specific data on preventive health practices and risk behaviors that are relevant to public health in the US adult population. As a result, the investigators were able to segment the findings by sociodemographic and lifestyle factors.
They found that black and multi-racial respondents were more likely than others to meet or exceed the minimum MSE recommendations. People who did not adhere tended to be older, female, overweight, or obese, did less aerobic activity, had lower income and education, and rated their own health as poor.
Surprisingly, while strength training is recognized as being important, it has been largely ignored in public health approaches for the prevention and management of chronic diseases. When performed regularly, strength training increases skeletal muscle strength, power, endurance, and mass.
Previous research has shown that this type of exercise has multiple health benefits including improved glucose and lipid metabolism, blood pressure, bone density, balance/physical function, and self-esteem and reduces anxiety.
However, the investigators were also careful to point out that it could also be said that people with adverse health conditions may be less likely to do strength training type exercises so, their study didn’t allow them to infer causality or reverse causality.
Lift Hard, Lift Long, Live Strong
One thing that we hope comes out of these types of studies is an appreciation by public health authorities of the need for more uptake of strength training with a greater support of its benefits in their directives.
Compared to the simplicity of aerobic type activities, which basically ask you to cover a certain distance on foot, in a pool, or on a bike, strength training requires some commitment to understanding complex concepts like periodization, progression, and the additional skills needed to work with everything from suspension trainers to barbells and kettlebells.
Bodybuilding may also be the only exposure that most people have to strength training type activities and there are some negatives associated with the things like bulking up, the risk of injury, and even the overtly hyper-masculine settings that represent strength training facilities.
The investigators hope that this study will provide a stimulus for future public health approaches to get greater proportions of the population engaged in MSE.
"We hope that these findings put MSE front and center on the agenda as a key health behavior in the prevention and management of chronic diseases," Dr. Bennie added, noting that the World Health Organization's 2010 Global Recommendations on Physical Activity for Health states that adults (aged 18-64) should participate in MSE involving large muscle groups at least two days a week, in addition to 150 minutes or more of vigorous aerobic exercise.
1. Jason A. Bennie, Duck-chul Lee, Asaduzzaman Khan, Glen H. Wiesner, Adrian E. Bauman, Emmanuel Stamatakis, Stuart J.H. Biddle. Muscle-Strengthening Exercise Among 397,423 U.S. Adults: Prevalence, Correlates, and Associations With Health Conditions. American Journal of Preventive Medicine, 2018.