Psychometric Evaluation of the Timeline Followback for Exercise among College Students

OBJECTIVES: Two separate studies assessed the psychometric properties of a retrospective behavioral measure adapted for exercise called the Timeline Followback for Exercise (TLFB-E). Study one examined criterion, convergent, and predictive validity. Study two examined test-retest reliability. METHODS: Study one participants (N = 66) were college students 20.0 ± 1.4yr. Validity of frequency, intensity, time, and type (FITT) of exercise as assessed on the TLFB-E was examined using Pearson r correlations with accelerometers, weekly exercise contracts between participants and researchers, question four of the College Alumni Questionnaire, and a health-related physical fitness battery. Study two participants were a different sample (N = 40) of college students 18.63 ± 1.0yr. Pearson r correlations determined reliability of the TLFB-E for exercise frequency, intensity, and time between two interviews separated by one month. Kappa statistic determined reliability of the TLFB-E for type of exercise. RESULTS: The TLFB-E displayed evidence of criterion validity when compared to accelerometers (r = .35 to .39) and evidence of convergent validity when compared to weekly exercise contracts (r = .65 to .80) and question four of the College Alumni Questionnaire (r = .06 to .75). The TLFB-E displayed evidence of modest to adequate test-retest reliability (r = .79 to .97) for exercise frequency, intensity, and time and moderate Kappa (k = .49) for exercise type. CONCLUSIONS: The TLFB-E produces evidence of reliable and valid scores among college students and improves upon other self-report, retrospective questionnaires by enabling daily collection of exercise FITT over a specified time period.