Muscle strengthening, aerobic exercise, and obesity

Objective: Both aerobic physical activity and muscle-strengthening exercise are recommended for obesity prevention. However, at the population level, the independent and/or combined associations of these physical activity modalities with obesity are unknown. The aim of this study was to examine the associations between aerobic physical activity and muscle-strengthening exercise with obesity among a representative sample of adults.

Methods: Data were pooled from four US public health surveillance surveys from 2011 to 2017. Cross-sectional associations between adherence to the aerobic physical activity (≥ 150 min/wk) and muscle-strengthening exercise (≥ 2 times/wk) guidelines with different classes of BMI-defined obesity were examined using Poisson regression. Prevalence ratios are reported as both unadjusted and adjusted for sociodemographic and lifestyle characteristics.

Results: Data were available for 1,677,108 adults (≥ 18 years old). Compared with meeting neither guideline (reference category), meeting both guidelines was associated with the lowest adjusted prevalence ratios (APRs) for the following: Class I obesity and above (BMI ≥ 30.0 kg/m2), APR = 0.54 (95% CI: 0.53-0.54); Class II obesity and above (BMI ≥ 35.0 kg/m2), APR = 0.32 (95% CI: 0.31-0.33); and Class III obesity and above (BMI ≥ 40.0 kg/m2), APR = 0.21 (95% CI: 0.20-0.21).

Conclusions: Among nearly 1.7 million US adults, meeting both aerobic and muscle-strengthening exercise guidelines was associated with a lower obesity prevalence, and associations were more pronounced for higher obesity classes.

Study Importance

What is already known about this subject?

• Physical activity is a key modifiable lifestyle behavior for obesity prevention, with most evidence on physical activity for a healthy weight based on studies of aerobic physical activity (walking, cycling, running).
• Emerging evidence suggests that muscle-strengthening exercise may be independently associated with the prevention of weight gain.
• However, at the population level, the independent and/or combined associations between aerobic and muscle-strengthening exercise and obesity are unknown.

What does your study add?

• Compared with other physical activity categories, meeting both aerobic and muscle-strengthening exercise guidelines was associated with the lowest prevalence of obesity.
• The strength of association between physical activity categories and obesity increased with increasing levels of obesity severity.
• Large-scale physical activity interventions that support the uptake/adherence of combined aerobic and muscle-strengthening exercise may be beneficial in reducing or preventing the severity of obesity.