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

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

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.

Inclusion Criteria:

• Males and females 18 to 40 years of age.
• Ability to safely ride an electric scooter (e-scooter) for at least 10 minutes.
• Active (>7000 steps per day, walking > 1 mile a day outside)
• Stable body weight for at least 1 year
• aerobic fitness level, CRF is < 9 and >14 METS
• Visceral adipose tissue <130 cm2 or ≥130 cm2 for men and <100 cm2 or ≥100 cm for women

Exclusion Criteria:

• Any injury preventing them from exercising regularly at the time of the screening.
• Implantable defibrillator or pacemaker
• Active cancer
• Alcohol or drug abuse
• Use of an assistive walking device
• Presence of significant signs/symptoms of cardiovascular, metabolic, or pulmonary disease (determined from the American College of Sports Medicine (ACSM) Health History Questionnaire)
• Daily vitamin consumption of > 500mg per day during the study
• Acetaminophen or aspirin use during the study