Interactive Roles of Cardiorespiratory Fitness and Adiposity on Recovery of Impaired Glucose and Vascular Control After Physical Inactivity

Summary

The far-reaching negative health effects of the reduced physical activity (RPA) epidemic are often overlooked by the general population and health professionals. Short-term RPA induces cardiometabolic dysfunction, including impaired glucose control and vascular function, that may precede disease development. The impact of existing health status on RPA-induced cardiometabolic dysfunction and recovery of impaired glucose control following RPA is unexplored. Thus, the investigators' objectives are 1) to investigate the effect of existing health status (cardiorespiratory fitness and adiposity) on the recovery of impaired glucose control following a period of RPA and 2) to determine the role of vascular function as a mechanism of impaired glucose control. The investigators' final objective is to 3) expose undergraduate students to meritorious biomedical clinical research methods. The investigators have piloted the clinical research methods and analysis with undergraduate researcher associates and are well-prepared to complete this proposal. Preliminary data show that low cardiorespiratory fitness and/or high adiposity impair the recovery of glucose control following short-term RPA. Thus, the investigators aim to examine the interactive role of health status (cardiorespiratory fitness and adiposity) on the ability to recover impaired glucose control following short-term RPA. The investigators also seek to examine changes in vascular function as a mechanism of recovery of impaired glucose control following a return to normal PA. The investigators will recruit men and women with divergent health status (cardiorespiratory fitness and adiposity) to examine glucose control and vascular function during 7-d of normal PA, 7-d of RPA, and 7-d of resumption of normal RA. Continuous glucose monitoring and oral glucose tolerance tests will be performed to assess glucose control. Increases in vascular shear stress induced by passive leg movement and central arterial stiffness will be measured to assess vascular function.

Eligibility

Age range

18–40 years

Sex

All

Healthy volunteers

Yes

Interventions

• Other
  reduced physical activity

  Each participant will undergo a three-week study. For the first week (day -7 to day 0), participants will be instructed to maintain their normal level of physical activity. For the second week (day 0 to day 7), the reduced physical activity (RPA) week, participants' schedules will be examined, and strategies designed to reduce steps (by at least 2000 steps) and physical activity (by taking elevators and short-cuts, etc.) by increasing sitting time \>10%. To assist in reducing walking and increased sitting, participants will be given seated electric scooters to use whenever they normally walk. The scooters will be returned on the third week (day 7 to day 14), and participants will be instructed to resume their normal physical activity. During the entire three weeks, participants will wear a continuous glucose monitor (CGM) and a physical activity monitor (ActivPal).

Location