PURPOSE: This study was conducted to provide descriptive data of accelerometer-determined ambulatory physical activity in a sample of free-living college students and to examine college students' ambulatory physical activity patterns. METHODS: All participants (245 females, age = 19.9 +/- 1.6 yr, body mass index (BMI) = 22.9 +/- 3.3 kg x m[-2],209 males, age = 20.2 +/- 2.0 yr, BMI = 25.2 +/- 4.0 kg x m[-2]) wore an accelerometer for seven consecutive days. Accumulated physical activity (ct x d[-1], ct x min[-1] x d[-1], and min x d[-1] spent at different intensities) and minutes per day spent in moderate or vigorous physical activity in sessions of at least 10 min were analyzed to describe the physical activity of the sample and examine physical activity patterns. RESULTS: The entire sample accumulated 362,750.1 +/- 112,824.1 ct x d[-1] (males = 383,787.2 +/- 112,001.3 vs females = 344,804.1 +/- 110,619.5 ct x d[-1], P < 0.01) and 46.7 +/- 18.9 min x d[-1] in moderate physical activity (males = 51.7 +/- 19.8 vs females = 42.5 +/- 17.0 min x d[-1], P < 0.01). They were more active on weekdays than weekend days (P < 0.05), and they spent 13.6 +/- 12.7 min.d (males = 13.2 +/- 12.0 vs females = 13.8 +/- 13.3, P > 0.05) in moderate or vigorous physical activity sessions of at least 10 min. CONCLUSION: Participants in this study accumulated a moderate amount of physical activity on most weekdays. Most participants, however, were not meeting the current moderate physical activity recommendation when moderate or vigorous physical activity sessions of at least 10 min were examined. [ABSTRACT FROM AUTHOR]