Timing Intervention of Morning Versus Evening Exercise

Inclusion Criteria: * Female or Male * Age 18-55 years * Body Mass Index 25-40 kg/m2 * Physically inactive: defined as self-reporting \<150 minutes per week of physical activity at moderate intensity or greater on a regular basis over the past 3 months. * No self-report of acute or chronic disease (cardiovascular disease (CVD), diabetes, gastrointestinal disorders and orthopedic problems in particular) * No plans to relocate within the next 15 months. * No plans for extended travel (\> 2 weeks) within the next 13 months * Live or work within 30 minutes of the Anschutz Health \& Wellness Center (AHWC) (exceptions may be made at the discretion of the Study PI on a case-by-case basis for highly motivated subjects). * Capable and willing to give informed consent, understand exclusion criteria, accept the randomized group assignment, and complete outcome measures. * No contraindications to exercise or limitations on ability to be physically active. * Willing to be randomized to either AM or PM exercise and complete 4 exercise sessions per week. * Own a smart phone and willing to download and use text messaging for meal intake and other related assessments. * Willing and able to wear activity/sleep monitor for 7-14 consecutive days. * Willing not to enroll in any other formal weight loss or physical activity programs over the next 13 months. * Fully vaccinated, or willing to be fully vaccinated, against COVID-19 prior to study enrollment (fully vaccinated is defined as at least 2 …