Understanding the Health Impact of Inactivity

The Understanding the Health Impacts of Inactivity research project study, monitors changes in physical function and in blood indicators of cardiovascular, muscular, skeletal, metabolic, and nutritional health and the effect of bed rest on changes in cognitive function and spiritual well-being.

Older adults confined to bed rest with their heads slightly tilted down, experience unloading of the heart, muscles and bones that can cause rapid deconditioning. The changes are similar to the responses astronauts experience during spaceflight. Our research group measured “aging-like” increases in arterial stiffness and insulin resistance in astronauts who have reduced aerobic fitness because of their extended periods of inactivity while floating in space.

In this study, we will introduce a new concept for bed rest studies by determining the biological age in addition to the chronological age of each participant. We anticipate that persons with an older biological age will have larger decreases in their body health during the bed rest. We anticipate as well that half of the older adults in the study who are asked to complete a specific exercise regime while in bed rest will have fewer changes in their health indicators.

The results from our study will provide unique information for astronauts to maintain health while in space. Importantly for us on Earth, our results will inform older adults and health care providers about causes of physical deterioration with bed rest and of the benefits of daily exercise even if confined to bed.