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: 297/5/R1441    most recent 00351.2009v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Coffey, V. G. Articles by Hawley, J. A. PubMed PubMed Citation Articles by Coffey, V. G. Articles by Hawley, J. A.

Articles

Effect of consecutive repeated sprint and resistance exercise bouts on acute adaptive responses in human skeletal muscle

¹Exercise Metabolism Group, School of Medical Science, RMIT, Melbourne, Australia; ²Human Performance Laboratory, Ball State University, Indiana; ³Sport and Exercise Science Division, Institute of Food, Nutrition and Human Health, Massey University, New Zealand; ⁴Department of Sport and Exercise, University of Auckland, New Zealand; and ⁵School of Exercise and Nutrition Sciences, Deakin University, Melbourne, Australia

Submitted June 19, 2009 ; accepted in final form August 18, 2009

We examined acute molecular responses in skeletal muscle to repeated sprint and resistance exercise bouts. Six men [age, 24.7 ± 6.3 yr; body mass, 81.6 ± 7.3 kg; peak oxygen uptake, 47 ± 9.9 ml·kg^–1·min^–1; one repetition maximum (1-RM) leg extension 92.2 ± 12.5 kg; means ± SD] were randomly assigned to trials consisting of either resistance exercise (8 x 5 leg extension, 80% 1-RM) followed by repeated sprints (10 x 6 s, 0.75 N·m torque·kg^–1) or vice-versa. Muscle biopsies from vastus lateralis were obtained at rest, 15 min after each exercise bout, and following 3-h recovery to determine early signaling and mRNA responses. There was divergent exercise order-dependent phosphorylation of p70 S6K (S6K). Specifically, initial resistance exercise increased S6K phosphorylation (75% P < 0.05), but there was no effect when resistance exercise was undertaken after sprints. Exercise decreased IGF-I mRNA following 3-h recovery (50%, P = 0.06) independent of order, while muscle RING finger mRNA was elevated with a moderate exercise order effect (P < 0.01). When resistance exercise was followed by repeated sprints PGC-1 mRNA was increased (REX1-SPR2; P = 0.02) with a modest distinction between exercise orders. Repeated sprints may promote acute interference on resistance exercise responses by attenuating translation initiation signaling and exacerbating ubiquitin ligase expression. Indeed, repeated sprints appear to generate the overriding acute exercise-induced response when undertaking concurrent repeated sprint and resistance exercise. Accordingly, we suggest that sprint-activities are isolated from resistance training and that adequate recovery time is considered within periodized training plans that incorporate these divergent exercise modes.

repeated sprint ability; resistance training; adaptation