Two weeks of reduced activity and skeletal muscle health in older men
Research type
Research Study
Full title
Effect of 14-days of reduced physical activity on muscle function and size, inflammatory profile, and exercise-induced activation of stress responses in skeletal muscle in healthy older males
IRAS ID
169122
Contact name
Oliver Perkin
Contact email
Sponsor organisation
University of Bath
Duration of Study in the UK
2 years, 5 months, 30 days
Research summary
Muscle size declines at around 0.5-1% per year after 50 years of age, with muscle strength declining up to twice as fast muscle size. This may eventually lead to loss of independence if tasks of daily living become too strenuous to be performed safely. Short periods of bed rest induce very rapid loss of muscle size and strength, and studies using healthy older participants have shown that age increases vulnerability to this muscle loss. However, it is unlikely that healthy individuals would be faced with extended periods of bed rest unless suffering a severe illness. In light of this, recent evidence has shown that even just reducing walking to less than 1,500 steps per day for two weeks caused 4% loss of leg muscle in over 65 year olds. This amount of activity is roughly the equivalent of being housebound, something that may become more common into older age, for example due to prolonged inclement weather, or minor injury or illness. This study will investigate the physiological causes of such stark muscle loss during two weeks of reduced activity, and the impact on skeletal muscle function and size, as well as balance, body composition, and other indicators of general health such as how the body responds to food or exercise. Importantly, we will also investigate exercise strategies that we believe could reduce muscle loss during a period of reduced activity. We will explore whether regular strength exercise before two weeks of reduced activity, or simple home based exercise ‘snacking’ during two weeks of reduced activity, can protect against muscle loss and affect how muscle is re-gained afterwards. With the increasing age of the population, this research aims to provide potential methods to minimise loss of muscle function due to inactivity that can lead to frailty in the elderly.
REC name
South West - Cornwall & Plymouth Research Ethics Committee
REC reference
15/SW/0130
Date of REC Opinion
16 Jun 2015
REC opinion
Further Information Favourable Opinion