Self‐rated physical fitness and measured cardiorespiratory fitness, muscular strength, and body composition

The purpose was to examine the correlation and association between a single-item question of self-rated physical fitness objective measures cardiometabolic risk factors in large population-based study. Participants were 3441 men women aged 18-85 years who filled questionnaire participated clinical health examination Danish Health Examination Survey 2007-2008. Cardiorespiratory estimated by an indirect maximal exercise test. Muscle strength measured (a) sit-to-stand test, (b) handgrip strength, (c) bent arm strength. Body mass index fat percentage used as for body composition. Associations derived from regression analyses, correlations calculated using Spearman's agreement tested kappa statistics. Within categories moving lowest highest, objectively cardiorespiratory increased. Self-rated strongly correlated (rmen  = 0.69 rwomen  = 0.65) moderately test  = 0.49  = 0.48), (r = 0.45) 0.46) among men, =0.41). Mutually adjusted analysis showed significant self-reported women. fitness, muscle However, this study suggests that it mainly captures fitness. At population level, could be useful tool identify monitor variation levels.