Physical activity in an inpatient setting is often limited to brief periods of walking. For healthy adults, public health agencies recommend a minimum of 150 min/week of moderate-intensity exercise. The authors sought to determine if meeting this activity threshold, in the absence of incidental activities of daily living, could protect skeletal muscle health during bed rest. Healthy older adults (68 ± 2 years) were randomized to 7-day bed rest with (STEP, n = 7) or without (CON, n = 10) a 2,000 steps/day intervention. Performing 2018 ± 4 steps/day did not prevent the loss of lean leg mass and had no beneficial effect on aerobic capacity, strength, or muscle fiber volume. However, the insulin response to an oral glucose challenge was preserved. Performing a block of 2,000 steps/day, in the absence of incidental activities of daily living, was insufficient to fully counter the catabolic effects of bed rest in healthy older adults.
|Number of pages||7|
|Journal||Journal of Aging and Physical Activity|
|State||Published - 2019|
Bibliographical noteFunding Information:
We sincerely thank Sneha Nagamma, Rachael Deer, Syed Husaini, Adetutu Odejimi, Jessica Spahn, and Elena Volpi, as well as the nurses and staff of the Institute for Translational Science – Clinical Research Center for their assistance with subject monitoring, data collection, and analysis. This work was supported by the National Institutes of Health (R01 NR012973 to D. Paddon-Jones) and in part by the Claude D. Pepper Older Americans Independence Center grant (P30 AG024832) and the National Center for Research Resources (1UL1RR029876). The study was conducted with the support of the Institute for Translational Sciences, supported in part by Clinical and Translational Science Awards (UL1TR000071 and UL1TR001439) from the National Center for Advancing Translational Sciences. The authors report no conflicts of interest. D. Paddon-Jones conceived and designed the study. E. Arentson-Lantz, E. Galvan, A. Wacher, C. S. Fry, and D. Paddon-Jones participated in subject management, data collection, and sample analysis.
© 2019 Human Kinetics, Inc.
- muscle function
- physical activity
ASJC Scopus subject areas
- Physical Therapy, Sports Therapy and Rehabilitation
- Geriatrics and Gerontology