| Title |
Muscle hypertrophy, hormonal adaptations and strength development during strength training in strength-trained and untrained men
|
|---|---|
| Published in |
European Journal of Applied Physiology, May 2003
|
| DOI | 10.1007/s00421-003-0833-3 |
| Pubmed ID | |
| Authors |
Juha P. Ahtiainen, Arto Pakarinen, Markku Alen, William J. Kraemer, Keijo Häkkinen |
| 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. |
X Demographics
The data shown below were collected from the profiles of 14 X users who shared this research output. Click here to find out more about how the information was compiled.
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| Spain | 1 | 7% |
| Brazil | 1 | 7% |
| Australia | 1 | 7% |
| Unknown | 11 | 79% |
Demographic breakdown
| Type | Count | As % |
|---|---|---|
| Members of the public | 11 | 79% |
| Scientists | 3 | 21% |
Mendeley readers
The data shown below were compiled from readership statistics for 652 Mendeley readers of this research output. Click here to see the associated Mendeley record.
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| Brazil | 7 | 1% |
| United States | 4 | <1% |
| Germany | 2 | <1% |
| New Zealand | 2 | <1% |
| Spain | 2 | <1% |
| United Kingdom | 2 | <1% |
| France | 1 | <1% |
| Chile | 1 | <1% |
| Malaysia | 1 | <1% |
| Other | 4 | <1% |
| Unknown | 626 | 96% |
Demographic breakdown
| Readers by professional status | Count | As % |
|---|---|---|
| Student > Master | 104 | 16% |
| Student > Bachelor | 101 | 15% |
| Student > Ph. D. Student | 89 | 14% |
| Researcher | 47 | 7% |
| Professor | 40 | 6% |
| Other | 138 | 21% |
| Unknown | 133 | 20% |
| Readers by discipline | Count | As % |
|---|---|---|
| Sports and Recreations | 272 | 42% |
| Medicine and Dentistry | 69 | 11% |
| Agricultural and Biological Sciences | 51 | 8% |
| Nursing and Health Professions | 23 | 4% |
| Biochemistry, Genetics and Molecular Biology | 21 | 3% |
| Other | 60 | 9% |
| Unknown | 156 | 24% |
Attention Score in Context
This research output has an Altmetric Attention Score of 41. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 11 August 2023.
All research outputs
#997,094
of 25,373,627 outputs
Outputs from European Journal of Applied Physiology
#300
of 4,345 outputs
Outputs of similar age
#896
of 54,737 outputs
Outputs of similar age from European Journal of Applied Physiology
#2
of 19 outputs
Altmetric has tracked 25,373,627 research outputs across all sources so far. Compared to these this one has done particularly well and is in the 96th percentile: it's in the top 5% of all research outputs ever tracked by Altmetric.
So far Altmetric has tracked 4,345 research outputs from this source. They typically receive a lot more attention than average, with a mean Attention Score of 14.6. This one has done particularly well, scoring higher than 93% of its peers.
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We're also able to compare this research output to 19 others from the same source and published within six weeks on either side of this one. This one has done well, scoring higher than 89% of its contemporaries.