Relationship between self-reported and objectively measured physical fitness in young men and women.

Self-reported physical fitness has advantages in cost and time over objective methods, but previous studies demonstrate equivocal conclusions regarding validity. Methods for self-reporting are usually based on subjective judgements, while another approach includes performing field tests at home. The Norwegian military relies on the latter method for conscript selection, but its validity is unknown and should be investigated. In total 14,166 young men and women were included in the study. During conscript selection step one, the subjects were requested to perform 3,000 m run, push-up, pull-up and standing long jump tests at home, and report the results online ("self-reported measurements"). Step two took place at a conscript selection centre 1-18 months later. Here, the subjects completed a maximal treadmill test, seated medicine ball throw, pull-up and standing long jump tests ("objective measurements"). The results demonstrated correlation coefficients from 0.29 to 0.82 ( < 0.05) for self-reported vs. objective measurements, with the highest association found for self-reported and objectively measured pull-ups. Kappa values ranged from 0.05 to 0.34 ( < 0.05), with pull-ups demonstrating the highest agreement. More women than men over-reported their physical fitness. Among men and women indicating similar self-reported fitness, men's objective fitness was higher for all objective tests (effect sizes from 0.5 to 3.0). In conclusion, large variations in correlation coefficients were observed between self-reported and objectively measured physical fitness, while the kappa values indicated poor to fair agreement. The finding that more women than men over-reported their fitness level contradicts most previous studies. Low, moderate, and high correlations, and poor to fair agreements (kappa values), were observed between self-reported and objectively measured endurance and muscle strength variables.More women than men overreported their actual fitness level.Self-reported fitness based on performing field tests at home may be a feasible alternative to traditional methods which rely on self-perceived fitness.