PROJECT SUMMARY/ABSTRACT Background: Rates of obesity in the United States have doubled over the last 30 years, as has the percentage of persons in the U.S. with diagnosed Type 2 diabetes mellitus (T2DM), and both conditions are rapidly increasing worldwide. Although changes in diet and energy expenditure have played an important role, sleep deficiency and circadian misalignment are risk factors for the development of obesity, insulin resistance and T2DM. Humans spend up to one third of their lives asleep and yet the function of sleep remains a topic of intense debate. While evidence supports a role for sleep in learning, memory and other central nervous system functions, well-controlled laboratory studies have demonstrated that sleep restriction has adverse effects on metabolism, both at the whole body, as well as molecular level. However, few studies to date have examined countermeasures to sleep loss and associated circadian misalignment. Research: The proposed study will assess the role of physical activity in mitigating physiological impairments associated with insufficient sleep, as well as provide complimentary training necessary to pursue a future independent scientific career at the intersection of metabolism and sleep/circadian biology.