Muscular Strength Is Inversely Related to Prevalence and Incidence of Obesity in Adult Men

The purpose of the study was to determine the relation between quintiles of muscular strength after adjustment for age and body weight, and excessive body fat (EBF) and excessive abdominal fat (EAF) when controlling for cardiorespiratory fitness (CRF) and other potential confounders. A two-phased cross-sectional and longitudinal study was conducted assessing the prevalence and incidence of EBF and EAF across quintiles of muscular strength. The sample included 3,258 men (mean age = 42.2 +/- 8.9; weight (kg) = 81.2 +/- 11.0; BMI = 25.3 +/- 2.9; % fat = 19.4 +/- 5.8; waist girth (cm) = 91.2 +/- 9.0) who completed at least two clinical examinations as part of the Aerobics Center Longitudinal Study (ACLS). Muscular strength was assessed with tests of upper and lower body muscular strength using rack-mounted weights with participants placed into strength quintiles. CRF was measured by a modified Balke treadmill test, % fat via underwater weighing or seven-site skinfold measurements, and waist girth measured at the level of the umbilicus. EBF was defined as >= 25% and EAF was defined as >102 cm. There was a strong inverse gradient across quintiles of muscular strength for prevalence and incidence of EBF and EAF (P trend <0.01, each). With the lowest quintile serving as the referent, reductions in risk of EBF and EAF exceeded 70% for the highest strength quintile. Evidence suggests muscular strength may provide protection from EBF and EAF and their related comorbidities.