Older Adults Exercising On Time

The investigators will compare our interventions to a 14-day period of sedentary behavior, during which the participant will refrain from any moderate to vigorous exercise. Next, participants will participate in two interventions consisting each of a 14-day physical activity regimen. The active morning and active evening interventions are equal in content. Both groups will be instructed to refrain from any moderate to vigorous exercise for the rest of the day. Per intervention, a total of eight Vitality Club training session comprising of a combination of aerobic endurance training and resistance exercise training will be given by a trained sports coach or physical therapist specialized in geriatric physical therapy. During the weekends, participants will be asked to perform a 'relative rest' session with some light activity during the training time window of the intervention arm.