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) All Versions of this Article: 106/6/2026    most recent 91481.2008v1 Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend 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 Google Scholar Articles by Kumar, V. Articles by Rennie, M. J. PubMed PubMed Citation Articles by Kumar, V. Articles by Rennie, M. J.

REVIEW

HIGHLIGHTED TOPIC
Regulation of Protein Metabolism in Exercise and Recovery

Human muscle protein synthesis and breakdown during and after exercise

University of Nottingham, School of Graduate Entry Medicine and Health, Derby, United Kingdom

Submitted 13 November 2008 ; accepted in final form 17 January 2009

ABSTRACT

Skeletal muscle demonstrates extraordinary mutability in its responses to exercise of different modes, intensity, and duration, which must involve alterations of muscle protein turnover, both acutely and chronically. Here, we bring together information on the alterations in the rates of synthesis and degradation of human muscle protein by different types of exercise and the influences of nutrition, age, and sexual dimorphism. Where possible, we summarize the likely changes in activity of signaling proteins associated with control of protein turnover. Exercise of both the resistance and nonresistance types appears to depress muscle protein synthesis (MPS), whereas muscle protein breakdown (MPB) probably remains unchanged during exercise. However, both MPS and MPB are elevated after exercise in the fasted state, when net muscle protein balance remains negative. Positive net balance is achieved only when amino acid availability is increased, thereby raising MPS markedly. However, postexercise-increased amino acid availability is less important for inhibiting MPB than insulin, the secretion of which is stimulated most by glucose availability, without itself stimulating MPS. Exercise training appears to increase basal muscle protein turnover, with differential responses of the myofibrillar and mitochondrial protein fractions to acute exercise in the trained state. Aging reduces the responses of myofibrillar protein and anabolic signaling to resistance exercise. There appear to be few, if any, differences in the response of young women and young men to acute exercise, although there are indications that, in older women, the responses may be blunted more than in older men.

protein turnover; signaling; contractile activity; training

This article has been cited by other articles:

				Q. Jiao, Y. Bai, T. Akaike, H. Takeshima, Y. Ishikawa, and S. Minamisawa Sarcalumenin is essential for maintaining cardiac function during endurance exercise training Am J Physiol Heart Circ Physiol, August 1, 2009; 297(2): H576 - H582. [Abstract] [Full Text] [PDF]

				P. J. Atherton, N. J. Szewczyk, A. Selby, D. Rankin, K. Hillier, K. Smith, M. J. Rennie, and P. T. Loughna Cyclic stretch reduces myofibrillar protein synthesis despite increases in FAK and anabolic signalling in L6 cells J. Physiol., July 15, 2009; 587(14): 3719 - 3727. [Abstract] [Full Text] [PDF]

				A. J. Rose and E. A. Richter Regulatory mechanisms of skeletal muscle protein turnover during exercise J Appl Physiol, May 1, 2009; 106(5): 1702 - 1711. [Abstract] [Full Text] [PDF]

				B. B. Rasmussen and E. A. Richter The balancing act between the cellular processes of protein synthesis and breakdown: exercise as a model to understand the molecular mechanisms regulating muscle mass J Appl Physiol, April 1, 2009; 106(4): 1365 - 1366. [Full Text] [PDF]