(verbatim from application) Although lower extremity muscle strength is a reliable measure of impairment and an index of functional capacity in the elderly, peak power or the maximum capacity to perform muscular work per unit of time may play a more important role in functional independence and disability prevention than muscle strength alone. Recent work from our laboratory suggests that peak lower extremity power, compared to lower extremity strength, is a better predictor of performance-based function and is an independent predictor of self-reported disability in frail elderly women. Although progressive resistance training (PRT) has been effective in significantly increasing muscle strength and size, the effects of PRT on performance-based measures of function have been less dramatic. The proposed study will examine the physiologic and functional effects of a muscle power training intervention in comparison to traditional PRT in a community-based group of elderly men and women with moderate mobility limitation. The proposed study will test the hypothesis that lower extremity peak power training will result in greater improvements in function, as assessed by tests of physical performance, compared to strength training. We propose that the hypothesized mechanisms by which peak power training will exert these effects include: a larger increase in skeletal muscle mass, muscle fiber hypertrophy, an increased in vitro shortening velocity of isolated single fibers with no change in specific force. A randomized controlled intervention trial will be conducted with subjects (N=75) being assigned to a lower extremity (knee and hip extensors) peak power training intervention, PRT, or control group for 3 months. Primary outcomes of interest will be assessed at baseline, and 3 months and include: physiological tests of leg strength, power, and endurance; performance-based functional tests, balance and mobility; biochemical measurements of skeletal muscle biopsies including histochemical and contractile properties; and body composition assessed by dual energy x-ray absorptiometry. The results of this study will have important implications in evaluating the effects of lower extremity power training, a potentially more effective means of modifying the proximal determinants of physical disability in the frail elderly.

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Research Project (R01)
Project #
1R01AG018844-01
Application #
6230385
Study Section
Geriatrics and Rehabilitation Medicine (GRM)
Program Officer
Premen, Andre J
Project Start
2001-03-15
Project End
2004-02-28
Budget Start
2001-03-15
Budget End
2002-02-28
Support Year
1
Fiscal Year
2001
Total Cost
$315,090
Indirect Cost
Name
Boston University
Department
Other Health Professions
Type
Schools of Allied Health Profes
DUNS #
042250712
City
Boston
State
MA
Country
United States
Zip Code
02215
Trombetti, A; Reid, K F; Hars, M et al. (2016) Age-associated declines in muscle mass, strength, power, and physical performance: impact on fear of falling and quality of life. Osteoporos Int 27:463-71
Reid, Kieran F; Martin, Kimberly I; Doros, Gheorghe et al. (2015) Comparative effects of light or heavy resistance power training for improving lower extremity power and physical performance in mobility-limited older adults. J Gerontol A Biol Sci Med Sci 70:374-80
Fielding, Roger A (2015) A Summary of the Biological Basis of Frailty. Nestle Nutr Inst Workshop Ser 83:41-4
Clark, David J; Reid, Kieran F; Patten, Carolynn et al. (2014) Does quadriceps neuromuscular activation capability explain walking speed in older men and women? Exp Gerontol 55:49-53
Reid, Kieran F; Pasha, Evan; Doros, Gheorghe et al. (2014) Longitudinal decline of lower extremity muscle power in healthy and mobility-limited older adults: influence of muscle mass, strength, composition, neuromuscular activation and single fiber contractile properties. Eur J Appl Physiol 114:29-39
Clark, David J; Pojednic, Rachele M; Reid, Kieran F et al. (2013) Longitudinal decline of neuromuscular activation and power in healthy older adults. J Gerontol A Biol Sci Med Sci 68:1419-25
Heffernan, Kevin S; Chalé, Angela; Hau, Cynthia et al. (2012) Systemic vascular function is associated with muscular power in older adults. J Aging Res 2012:386387
Clark, David J; Fielding, Roger A (2012) Neuromuscular contributions to age-related weakness. J Gerontol A Biol Sci Med Sci 67:41-7
Pojednic, Rachele M; Clark, David J; Patten, Carolynn et al. (2012) The specific contributions of force and velocity to muscle power in older adults. Exp Gerontol 47:608-13
Reid, Kieran F; Doros, Gheorghe; Clark, David J et al. (2012) Muscle power failure in mobility-limited older adults: preserved single fiber function despite lower whole muscle size, quality and rate of neuromuscular activation. Eur J Appl Physiol 112:2289-301

Showing the most recent 10 out of 34 publications