HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Hortobágyi, T. Articles by DeVita, P. Search for Related Content PubMed PubMed Citation Articles by Hortobágyi, T. Articles by DeVita, P.

Low- or High-Intensity Strength Training Partially Restores Impaired Quadriceps Force Accuracy and Steadiness in Aged Adults

^a Biomechanics Laboratory, East Carolina University, Greenville, North Carolina

Tibor Hortobágyi, 251 Sports Medicine Building, East Carolina University, Greenville, NC 27858 E-mail: hortobagyit{at}mail.ecu.edu.

Decision Editor: John A. Faulkner, PhD

Because many daily tasks are executed at only a fraction of maximal strength, an understanding of submaximal force control may be important for improving function in aged adults. We compared the effects of low- and high-intensity (LI and HI, respectively) strength training on maximal and explosive strength and on the accuracy (force error) and steadiness (variability) of submaximal quadriceps force in elderly humans. Older subjects (age, 72 years; n = 27) had 57% lower maximal strength in comparison with young subjects (age, 21 years; n = 10). Older subjects had 190% (19 N), 50% (1 N), and 80% (4 N) more force error in matching 25 N of quadriceps force during eccentric, isometric, and concentric contractions, and had 157%, 0%, and 60% more variability in these forces compared with young subjects. Force error and force variability were correlated with each other but not with maximal strength. Thirty sessions of LI (n = 9 participants) or HI (n = 9 participants) training of equal total work increased maximal strength in the older subjects by 29%. Training also significantly reduced force error and variability—by 31% and 30%, respectively—of eccentric and concentric contractions. A control group of older subjects (n = 9) showed no significant changes in any variables. LI or HI strength training was equally effective in partially restoring elderly adults' maximal strength and control of submaximal force.

This article has been cited by other articles:

				M.-H. Jan, J.-J. Lin, J.-J. Liau, Y.-F. Lin, and D.-H. Lin Investigation of Clinical Effects of High- and Low-Resistance Training for Patients With Knee Osteoarthritis: A Randomized Controlled Trial Physical Therapy, April 1, 2008; 88(4): 427 - 436. [Abstract] [Full Text] [PDF]

				I G Fatouros, A Kambas, I Katrabasas, K Nikolaidis, A Chatzinikolaou, D Leontsini, and K Taxildaris Strength training and detraining effects on muscular strength, anaerobic power, and mobility of inactive older men are intensity dependent Br. J. Sports Med., October 1, 2005; 39(10): 776 - 780. [Abstract] [Full Text] [PDF]

				K. W. Kornatz, E. A. Christou, and R. M. Enoka Practice reduces motor unit discharge variability in a hand muscle and improves manual dexterity in old adults J Appl Physiol, June 1, 2005; 98(6): 2072 - 2080. [Abstract] [Full Text] [PDF]

				M. Kouzaki, M. Shinohara, K. Masani, and T. Fukunaga Force fluctuations are modulated by alternate muscle activity of knee extensor synergists during low-level sustained contraction J Appl Physiol, December 1, 2004; 97(6): 2121 - 2131. [Abstract] [Full Text] [PDF]

				B. L. Tracy, W. C. Byrnes, and R. M. Enoka Strength training reduces force fluctuations during anisometric contractions of the quadriceps femoris muscles in old adults J Appl Physiol, April 1, 2004; 96(4): 1530 - 1540. [Abstract] [Full Text] [PDF]

				T. J. Doherty Invited Review: Aging and sarcopenia J Appl Physiol, October 1, 2003; 95(4): 1717 - 1727. [Abstract] [Full Text] [PDF]

				M. Shinohara, Y. Yoshitake, M. Kouzaki, H. Fukuoka, and T. Fukunaga Strength training counteracts motor performance losses during bed rest J Appl Physiol, October 1, 2003; 95(4): 1485 - 1492. [Abstract] [Full Text] [PDF]

				P. C. LaStayo, G. A. Ewy, D. D. Pierotti, R. K. Johns, and S. Lindstedt The Positive Effects of Negative Work: Increased Muscle Strength and Decreased Fall Risk in a Frail Elderly Population J. Gerontol. A Biol. Sci. Med. Sci., May 1, 2003; 58(5): M419 - 424. [Abstract] [Full Text] [PDF]

				D. E. Vaillancourt and K. M. Newell Aging and the time and frequency structure of force output variability J Appl Physiol, March 1, 2003; 94(3): 903 - 912. [Abstract] [Full Text] [PDF]

				J. E. Morley, H. M. Perry III, and D. K. Miller Editorial: Something About Frailty J. Gerontol. A Biol. Sci. Med. Sci., November 1, 2002; 57(11): M698 - 704. [Full Text] [PDF]

				D. H. Laidlaw, S. K. Hunter, and R. M. Enoka Nonuniform activation of the agonist muscle does not covary with index finger acceleration in old adults J Appl Physiol, October 1, 2002; 93(4): 1400 - 1410. [Abstract] [Full Text] [PDF]

				A. Fisher and J. E. Morley Editorial: Antiaging Medicine: The Good, the Bad, and the Ugly J. Gerontol. A Biol. Sci. Med. Sci., October 1, 2002; 57(10): M636 - 639. [Full Text] [PDF]

				J. E. Morley and J. H. Flaherty Editorial: Putting the "Home" Back in Nursing Home J. Gerontol. A Biol. Sci. Med. Sci., July 1, 2002; 57(7): M419 - 421. [Full Text]

				B. L. Tracy and R. M. Enoka Older adults are less steady during submaximal isometric contractions with the knee extensor muscles J Appl Physiol, March 1, 2002; 92(3): 1004 - 1012. [Abstract] [Full Text] [PDF]

				D. R. Thomas The Critical Link Between Health-Related Quality of Life and Age-Related Changes in Physical Activity and Nutrition J. Gerontol. A Biol. Sci. Med. Sci., October 1, 2001; 56(10): M599 - 602. [Full Text] [PDF]