Association between self-reported and objectively measured physical fitness level in a middle-aged population in primary care.

Aim: To investigate the association between self-reported physical fitness level obtained by a single-item question and objectively measured fitness level in 30- to 49-year-old men and women.

Methods: From the Danish 'Check Your Health Preventive Program' 2013-2014 fitness level was assessed in 2316 participants using the Aastrand test. Additionally, participants rated their physical fitness as high, good, average, fair or low.