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Changes in muscle morphology, electromyographic activity, and force production characteristics during progressive strength training in young and older men.
J Gerontol A Biol Sci Med Sci. 1998 Nov; 53(6):B415-23.JG

Abstract

Effects of a 10-week progressive strength training program composed of a mixture of exercises for increasing muscle mass, maximal peak force, and explosive strength (rapid force production) were examined in 8 young (YM) (29+/-5 yrs) and 10 old (OM) (61+/-4 yrs) men. Electromyographic activity, maximal bilateral isometric peak force, and maximal rate of force development (RFD) of the knee extensors, muscle cross-sectional area (CSA) of the quadriceps femoris (QF), muscle fiber proportion, and fiber areas of types I, IIa, IIb, and IIab of the vastus lateralis were evaluated. Maximal and explosive strength values remained unaltered in both groups during a 3-week control period with no training preceding the strength training. After the 10-week training period, maximal isometric peak force increased from 1311+/-123 N by 15.6% (p <.05) in YM and from 976+/-168 N by 16.5% (p <.01) in OM. The pretraining RFD values of 4049+/-791 N*s(-1) in YM and 2526+/-1197 N*s(-1) in OM remained unaltered. Both groups showed significant increases (p < .05) in the averaged maximum IEMGs of the vastus muscles. The CSA of the QF increased from 90.3+/-7.9 cm2 in YM by 12.2% (p <.05) and from 74.7+/-7.8 cm2 in OM by 8.5% (p <.001). No changes occurred in the muscle fiber distribution of type I during the training, whereas the proportion of subtype IIab increased from 2% to 6% (p < .05) in YM and that of type IIb decreased in both YM from 25% to 16% (p < .01) and in OM from 15% to 6% (p < .05). The mean fiber area of type I increased after the 10-week training in YM (p < .001) and OM (p < .05) as well as that of type IIa in both YM (p < .01) and OM (p < .01). The individual percentage values for type I fibers were inversely correlated with the individual changes recorded during the training in the muscle CSA of the QF (r=-.56, p < .05). The present results suggest that both neural adaptations and the capacity of the skeletal muscle to undergo training-induced hypertrophy even in older people explain the gains observed in maximal force in older men, while rapid force production capacity recorded during the isometric knee extension action remained unaltered during the present mixed strength training program.

Authors+Show Affiliations

Neuromuscular Research Center and Department of Biology of Physical Activity, University of Jyväskylä, Finland. Hakkinen@maila.jyu.fiNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

9823737

Citation

Häkkinen, K, et al. "Changes in Muscle Morphology, Electromyographic Activity, and Force Production Characteristics During Progressive Strength Training in Young and Older Men." The Journals of Gerontology. Series A, Biological Sciences and Medical Sciences, vol. 53, no. 6, 1998, pp. B415-23.
Häkkinen K, Newton RU, Gordon SE, et al. Changes in muscle morphology, electromyographic activity, and force production characteristics during progressive strength training in young and older men. J Gerontol A Biol Sci Med Sci. 1998;53(6):B415-23.
Häkkinen, K., Newton, R. U., Gordon, S. E., McCormick, M., Volek, J. S., Nindl, B. C., Gotshalk, L. A., Campbell, W. W., Evans, W. J., Häkkinen, A., Humphries, B. J., & Kraemer, W. J. (1998). Changes in muscle morphology, electromyographic activity, and force production characteristics during progressive strength training in young and older men. The Journals of Gerontology. Series A, Biological Sciences and Medical Sciences, 53(6), B415-23.
Häkkinen K, et al. Changes in Muscle Morphology, Electromyographic Activity, and Force Production Characteristics During Progressive Strength Training in Young and Older Men. J Gerontol A Biol Sci Med Sci. 1998;53(6):B415-23. PubMed PMID: 9823737.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Changes in muscle morphology, electromyographic activity, and force production characteristics during progressive strength training in young and older men. AU - Häkkinen,K, AU - Newton,R U, AU - Gordon,S E, AU - McCormick,M, AU - Volek,J S, AU - Nindl,B C, AU - Gotshalk,L A, AU - Campbell,W W, AU - Evans,W J, AU - Häkkinen,A, AU - Humphries,B J, AU - Kraemer,W J, PY - 1998/11/21/pubmed PY - 1998/11/21/medline PY - 1998/11/21/entrez SP - B415 EP - 23 JF - The journals of gerontology. Series A, Biological sciences and medical sciences JO - J. Gerontol. A Biol. Sci. Med. Sci. VL - 53 IS - 6 N2 - Effects of a 10-week progressive strength training program composed of a mixture of exercises for increasing muscle mass, maximal peak force, and explosive strength (rapid force production) were examined in 8 young (YM) (29+/-5 yrs) and 10 old (OM) (61+/-4 yrs) men. Electromyographic activity, maximal bilateral isometric peak force, and maximal rate of force development (RFD) of the knee extensors, muscle cross-sectional area (CSA) of the quadriceps femoris (QF), muscle fiber proportion, and fiber areas of types I, IIa, IIb, and IIab of the vastus lateralis were evaluated. Maximal and explosive strength values remained unaltered in both groups during a 3-week control period with no training preceding the strength training. After the 10-week training period, maximal isometric peak force increased from 1311+/-123 N by 15.6% (p <.05) in YM and from 976+/-168 N by 16.5% (p <.01) in OM. The pretraining RFD values of 4049+/-791 N*s(-1) in YM and 2526+/-1197 N*s(-1) in OM remained unaltered. Both groups showed significant increases (p < .05) in the averaged maximum IEMGs of the vastus muscles. The CSA of the QF increased from 90.3+/-7.9 cm2 in YM by 12.2% (p <.05) and from 74.7+/-7.8 cm2 in OM by 8.5% (p <.001). No changes occurred in the muscle fiber distribution of type I during the training, whereas the proportion of subtype IIab increased from 2% to 6% (p < .05) in YM and that of type IIb decreased in both YM from 25% to 16% (p < .01) and in OM from 15% to 6% (p < .05). The mean fiber area of type I increased after the 10-week training in YM (p < .001) and OM (p < .05) as well as that of type IIa in both YM (p < .01) and OM (p < .01). The individual percentage values for type I fibers were inversely correlated with the individual changes recorded during the training in the muscle CSA of the QF (r=-.56, p < .05). The present results suggest that both neural adaptations and the capacity of the skeletal muscle to undergo training-induced hypertrophy even in older people explain the gains observed in maximal force in older men, while rapid force production capacity recorded during the isometric knee extension action remained unaltered during the present mixed strength training program. SN - 1079-5006 UR - https://www.unboundmedicine.com/medline/citation/9823737/Changes_in_muscle_morphology_electromyographic_activity_and_force_production_characteristics_during_progressive_strength_training_in_young_and_older_men_ L2 - https://academic.oup.com/biomedgerontology/article-lookup/doi/10.1093/gerona/53a.6.b415 DB - PRIME DP - Unbound Medicine ER -