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

This Article Full Text Free Full Text (PDF) Free All Versions of this Article: 103/5/1565    most recent 00578.2007v1 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 ISI Web of Science 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 ISI Web of Science (7) Citing Articles via Google Scholar Google Scholar Articles by Blazevich, A. J. Articles by Horne, S. Search for Related Content PubMed PubMed Citation Articles by Blazevich, A. J. Articles by Horne, S.

Influence of concentric and eccentric resistance training on architectural adaptation in human quadriceps muscles

Centre for Sports Medicine and Human Performance, School of Sport and Education, Brunel University, Uxbridge, United Kingdom

Submitted 30 May 2007 ; accepted in final form 15 August 2007

Studies using animal models have been unable to determine the mechanical stimuli that most influence muscle architectural adaptation. We examined the influence of contraction mode on muscle architectural change in humans, while also describing the time course of its adaptation through training and detraining. Twenty-one men and women performed slow-speed (30°/s) concentric-only (Con) or eccentric-only (Ecc) isokinetic knee extensor training for 10 wk before completing a 3-mo detraining period. Fascicle length of the vastus lateralis (VL), measured by ultrasonography, increased similarly in both groups after 5 wk (_Con = +6.3 ± 3.0%, _Ecc = +3.1 ± 1.6%, mean = +4.7 ± 1.7%; P < 0.05). No further increase was found at 10 wk, although a small increase (mean 2.5%; not significant) was evident after detraining. Fascicle angle increased in both groups at 5 wk (_Con = +11.1 ± 4.0%, _Ecc = +11.9 ± 5.4%, mean = 11.5 ± 3.2%; P < 0.05) and 10 wk (_Con = +13.3 ± 3.0%, _Ecc = +21.4 ± 6.9%, mean = 17.9 ± 3.7%; P < 0.01) in VL only and remained above baseline after detraining (mean = 13.2%); smaller changes in vastus medialis did not reach significance. The similar increase in fascicle length observed between the training groups mitigates against contraction mode being the predominant stimulus. Our data are also strongly indicative of 1) a close association between VL fascicle length and shifts in the torque-angle relationship through training and detraining and 2) changes in fascicle angle being driven by space constraints in the hypertrophying muscle. Thus muscle architectural adaptations occur rapidly in response to resistance training but are strongly influenced by factors other than contraction mode.

skeletal muscle; fascicle; muscle adaptation; muscle strength

This article has been cited by other articles:

				N. D. Reeves, C. N. Maganaris, S. Longo, and M. V. Narici Differential adaptations to eccentric versus conventional resistance training in older humans Exp Physiol, July 1, 2009; 94(7): 825 - 833. [Abstract] [Full Text] [PDF]