RecruitingBehavioural interventionStudent Exercise and Sleep Timing Study - Part 2The purpose of this study is to examine the effects of a morning exercise intervention on sleep (quality and duration), mood (positive affect, anxiety, depression, anger), stress and productivity among undergraduate students (18-23 years) evening-exercisers with poor self-reported sleep quality. Aim 1. Compared to the control condition, evening-exercisers prescribed morning exercise will exhibit improved sleep quality (increased efficiency, decreased fragmentation) and increased sleep duration. Aim 2. Compared to the control condition, evening-exercisers prescribed morning exercise will exhibit improved mood (increased positive affect, decreased depression, anxiety and anger). Aim 3. Compared to the control condition, evening-exercisers prescribed morning exercise will exhibit decreased stress and increased productivity.