An intervention was conducted to identify effective but feasible ways to combat the decline in physical activity (PA) among college students. One hundred forty-six first year college students were randomly assigned to one of three brief interventions: brochures, a classroom presentation, or an in-person demonstration. Benefiting from the study, having low perceived stress, and being in a later stage of change for PA were expected to protect against the typical decreases in PA outcomes. Declines in PA were slowed or reversed when students were influenced by the intervention, had lower stress, and were in earlier stages of change. Students may benefit from simple interventions such as one-time seminars and brochures explaining fitness guidelines, especially if combined with a stress management intervention.