Journal of Sports Science and Medicine
Journal of Sports Science and Medicine
ISSN: 1303 - 2968   
Ios-APP Journal of Sports Science and Medicine
Androit-APP Journal of Sports Science and Medicine
Views
6210
Download
174
from September 2014
 
©Journal of Sports Science and Medicine (2006) 05, 349 - 358

Research article, Young investigator
Adaptive Changes of Myosin Isoforms in Response to Long-Term Strength and Power Training in Middle-Aged Men
Raivo Puhke1, Sirkka Aunola2 , Pirjo Ailanto3, Karin Alev1, Mika Venojärvi2,4, Heikki Rusko5,6, Teet Seene1
Author Information
1 Institute of Exercise Biology and Physiotherapy, University of Tartu, Tartu, Estonia
2 Laboratory for Population Research, Department of Health and Functional Capacity, National Public Health Institute, Turku, Finland
3 Department of Physiology, University of Kuopio, Kuopio, Finland
4 Medical Laboratory Technology, Turku University of Applied Sciences, Turku, Finland
5 KIHU - Research Institute for Olympic Sports, Jyväskylä, Finland
6 Department of Biology of Physical Activity, University of Jyväskylä, Jyväskylä, Finland

Sirkka Aunola
✉ National Public Health Institute, Peltolantie 3, FI-20720, Turku, Finland
Email: sirkka.aunola@ktl.fi
Publish Date
Received: 08-11-2005
Accepted: 10-04-2006
Published (online): 01-06-2006
Share this article
 
 
ABSTRACT

The purpose of the study was to examine the adaptive changes in myosin heavy chain (MHC) and light chain (MLC) isoforms in human vastus lateralis muscle caused by long-term strength and power training (54 weeks, approximately 3 times a week) in untrained middle- aged men (16 in the training and 6 in the control group). Muscular MHC and MLC isoforms were determined by means of SDS-PAGE gel electrophoresis. During the training period, maximal anaerobic cycling power increased by 64 W (p < 0.001) and the maximal jumping height by 1.5 cm (p < 0. 05) in the training group, but no significant changes were found in the control group. However, the group by time effect was not significant. In the training group, the increase of the maximal jumping height correlated with the number of strength and power training sessions (r = 0.56; p < 0.05). The change of the proportion of MHC IIa isoform from 52.6 ± 12.2% to 59.4 ± 11.6% did not reach statistical significance (p = 0.070 for group by time; within training group p = 0.061) and neither did the change of the proportion of MHC IIx isoform from 18.1 ± 11.4% to 11.1 ± 9.1% (p = 0.104 for group by time; within training group p=0.032). The degree of change of MHC IIx isoform correlated with the amount of earlier recreational sports activity (r = 0.61; p < 0.05). In the training group, the changes of MLC1s isoform correlated negatively with the changes of MLC1f isoform (r = -0. 79; p < 0.05) as well as with the changes in maximal anaerobic cycling power (r = -0.81; p < 0.05), and positively with those of MHC I isoform (r = 0.81; p < 0.05). In conclusion, the long- term strength and power training ~3 times a week seemed to have only slight effects on fast MHC isoforms in the vastus lateralis muscle of untrained middle-aged men; the proportion of MHC IIa tended to increase and that of MHC IIx tended to decrease. No changes in MLC isoform profile could be shown.

Key words: Anaerobic muscular power, contractile proteins, myosin heavy chain isoforms, myosin light chain isoforms, training, transformation


           Key Points
  • A long-term strength and power training program seemed to decrease the proportion of MHC IIx isoform in previously untrained middle-aged men.
  • The degree of change of MHC IIx isoform correlated with the amount of earlier recreational sports activity.
  • The changes of MLC isoforms were associated with the transition of MHC isoforms. Whether this means improved speed and coordination of muscle contraction remains to be investigated in the future.
 
 
Home Issues About Authors
Contact Current Editorial board Authors instructions
Email alerts In Press Mission For Reviewers
Archive Scope
Supplements Statistics
Most Read Articles
  Most Cited Articles
 
  
 
JSSM | Copyright 2001-2020 | All rights reserved. | LEGAL NOTICES | Publisher

It is forbidden the total or partial reproduction of this web site and the published materials, the treatment of its database, any kind of transition and for any means, either electronic, mechanic or other methods, without the previous written permission of the JSSM.

This work is licensed under a Creative Commons License Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.