The validity of self-reported physical fitness test scores

Epidemiological studies often have to rely on a participant's self-reporting of information. The validity of the self-report instrument is an important consideration in any study. The purpose of this investigation was to determine the validity of self-reported Army Physical Fitness Test (APFT) scores. The APFT is administered to all soldiers in the U.S. Army twice a year and consists of the maximum number of push-ups completed in 2 minutes, the maximum number of sit-ups completed in 2 minutes, and a 2-mile run for time. Army mechanics responded to a questionnaire in March and June 2004 asking them to report the exact scores of each event on their most recent APFT. Actual APFT scores were obtained from the soldier's military unit. The mean +/- standard deviation (SD) of actual and self-reported numbers of push-ups was 61 +/- 14 and 65 +/- 13, respectively. The mean +/- SD of actual and self-reported numbers of sit-ups were 66 +/- 10 and 68 +/- 10, respectively. The mean +/- SD of actual and self-reported run times (minutes) were 14.8 +/- 1.4 and 14.6 +/- 1.4, respectively. Correlations between actual and self-reported push-ups, sit-ups, and run were 0.83, 0.71, and 0.85, respectively. On average, soldiers tended to slightly over-report performance on all APFT events and individual self-reported scores could vary widely from actual scores based on Bland-Altman plots. Despite this, the close correlations between the actual and self-reported scores suggest that self-reported values are adequate for most epidemiological military studies involving larger sample sizes.