Tags

Type your tag names separated by a space and hit enter

Muscle hypertrophy, hormonal adaptations and strength development during strength training in strength-trained and untrained men.
Eur J Appl Physiol. 2003 Aug; 89(6):555-63.EJ

Abstract

Hormonal and neuromuscular adaptations to strength training were studied in eight male strength athletes (SA) and eight non-strength athletes (NA). The experimental design comprised a 21-week strength-training period. Basal hormonal concentrations of serum total testosterone (T), free testosterone (FT) and cortisol (C) and maximal isometric strength, right leg 1 repetition maximum (RM) of the leg extensors were measured at weeks 0, 7, 14 and 21. Muscle cross-sectional area (CSA) of the quadriceps femoris was measured by magnetic resonance imaging (MRI) at weeks 0 and 21. In addition, the acute heavy resistance exercises (AHRE) (bilateral leg extension, five sets of ten RM, with a 2-min rest between sets) including blood samples for the determination of serum T, FT, C, and GH concentrations were assessed before and after the 21-week training. Significant increases of 20.9% in maximal force and of 5.6% in muscle CSA in NA during the 21-week strength training period were greater than those of 3.9% and -1.8% in SA, respectively. There were no significant changes in serum basal hormone concentrations during the 21-week experiment. AHRE led to significant acute decreases in isometric force and acute increases in serum hormones both at weeks 0 and 21. Basal T concentrations (mean of 0, 7, 14 and 21 weeks) and changes in isometric force after the 21-week period correlated with each other (r=0.84, P<0.01) in SA. The individual changes in the acute T responses between weeks 0 and 21 and the changes in muscle CSA during the 21-week training correlated with each other (r=0.76, P<0.05) in NA. The correlations between T and the changes in isometric strength and in muscle CSA suggest that both serum basal testosterone concentrations and training-induced changes in acute testosterone responses may be important factors for strength development and muscle hypertrophy.

Authors+Show Affiliations

Neuromuscular Research Center and Department of Biology of Physical Activity, University of Jyväskylä, P.O. Box 35, 40014 Jyväskylä, Finland. ahtiainen@sport.jyu.fiNo 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

12734759

Citation

Ahtiainen, Juha P., et al. "Muscle Hypertrophy, Hormonal Adaptations and Strength Development During Strength Training in Strength-trained and Untrained Men." European Journal of Applied Physiology, vol. 89, no. 6, 2003, pp. 555-63.
Ahtiainen JP, Pakarinen A, Alen M, et al. Muscle hypertrophy, hormonal adaptations and strength development during strength training in strength-trained and untrained men. Eur J Appl Physiol. 2003;89(6):555-63.
Ahtiainen, J. P., Pakarinen, A., Alen, M., Kraemer, W. J., & Häkkinen, K. (2003). Muscle hypertrophy, hormonal adaptations and strength development during strength training in strength-trained and untrained men. European Journal of Applied Physiology, 89(6), 555-63.
Ahtiainen JP, et al. Muscle Hypertrophy, Hormonal Adaptations and Strength Development During Strength Training in Strength-trained and Untrained Men. Eur J Appl Physiol. 2003;89(6):555-63. PubMed PMID: 12734759.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Muscle hypertrophy, hormonal adaptations and strength development during strength training in strength-trained and untrained men. AU - Ahtiainen,Juha P, AU - Pakarinen,Arto, AU - Alen,Markku, AU - Kraemer,William J, AU - Häkkinen,Keijo, Y1 - 2003/05/07/ PY - 2003/03/07/accepted PY - 2003/5/8/pubmed PY - 2003/12/3/medline PY - 2003/5/8/entrez SP - 555 EP - 63 JF - European journal of applied physiology JO - Eur. J. Appl. Physiol. VL - 89 IS - 6 N2 - Hormonal and neuromuscular adaptations to strength training were studied in eight male strength athletes (SA) and eight non-strength athletes (NA). The experimental design comprised a 21-week strength-training period. Basal hormonal concentrations of serum total testosterone (T), free testosterone (FT) and cortisol (C) and maximal isometric strength, right leg 1 repetition maximum (RM) of the leg extensors were measured at weeks 0, 7, 14 and 21. Muscle cross-sectional area (CSA) of the quadriceps femoris was measured by magnetic resonance imaging (MRI) at weeks 0 and 21. In addition, the acute heavy resistance exercises (AHRE) (bilateral leg extension, five sets of ten RM, with a 2-min rest between sets) including blood samples for the determination of serum T, FT, C, and GH concentrations were assessed before and after the 21-week training. Significant increases of 20.9% in maximal force and of 5.6% in muscle CSA in NA during the 21-week strength training period were greater than those of 3.9% and -1.8% in SA, respectively. There were no significant changes in serum basal hormone concentrations during the 21-week experiment. AHRE led to significant acute decreases in isometric force and acute increases in serum hormones both at weeks 0 and 21. Basal T concentrations (mean of 0, 7, 14 and 21 weeks) and changes in isometric force after the 21-week period correlated with each other (r=0.84, P<0.01) in SA. The individual changes in the acute T responses between weeks 0 and 21 and the changes in muscle CSA during the 21-week training correlated with each other (r=0.76, P<0.05) in NA. The correlations between T and the changes in isometric strength and in muscle CSA suggest that both serum basal testosterone concentrations and training-induced changes in acute testosterone responses may be important factors for strength development and muscle hypertrophy. SN - 1439-6319 UR - https://www.unboundmedicine.com/medline/citation/12734759/Muscle_hypertrophy_hormonal_adaptations_and_strength_development_during_strength_training_in_strength_trained_and_untrained_men_ L2 - https://dx.doi.org/10.1007/s00421-003-0833-3 DB - PRIME DP - Unbound Medicine ER -