Validity and reliability of self-reported physical activity status: the Lipid Research Clinics questionnaire

We assessed the validity and reliability of the Lipid Research Clinics (LRC) physical activity (PA) questionnaire against measures of PA and physical fitness, and compared a new scoring system (four-point) with the method used in the LRC studies (two-point) in 28 men and 50 women. The two-point method classified participants as inactive or active based one question about regular, strenuous exercise habits. The four-point method classified participants as very low, low, moderate, and high active based on two questions; regular, strenuous exercise and self-rating of PA relative to peers. After adjusting for age and gender, the four-point method explained 17-29% of the variation in VO2max, percent body fat, and heavy-and light-intensity kcal.d-1 measured by the 4 wk history questionnaire (FWH). No association was found between the LRC ratings and Caltrac kcal and activity units and FWH total, moderate-intensity, and household PA kcal.d-1. Test-retest reliability was high (two-point, r = 0.85; four-point, r = 0.88). The LRC PA questionnaire is a relatively valid and reliable indicator of heavy PA in adults. The four-point method increases the ability to show graded associations between measures of cardiorespiratory fitness, body fatness, and leisure time PA.