Ahtiainen Juha P, Pakarinen Arto, Alen Markku, Kraemer William J, Häkkinen Keijo
Department of Biology of Physical Activity & Neuromuscular Research Center, University of Jyväskylä, Jyväskylä, Finland.
J Strength Cond Res. 2005 Aug;19(3):572-82. doi: 10.1519/15604.1.
Acute and long-term hormonal and neuromuscular adaptations to hypertrophic strength training were studied in 13 recreationally strength-trained men. The experimental design comprised a 6-month hypertrophic strength-training period including 2 separate 3-month training periods with the crossover design, a training protocol of short rest (SR, 2 minutes) as compared with long rest (LR, 5 minutes) between the sets. Basal hormonal concentrations of serum total testosterone (T), free testosterone (FT), and cortisol (C), maximal isometric strength of the leg extensors, right leg 1 repetition maximum (1RM), dietary analysis, and muscle cross-sectional area (CSA) of the quadriceps femoris by magnetic resonance imaging (MRI) were measured at months 0, 3, and 6. The 2 hypertrophic training protocols used in training for the leg extensors (leg presses and squats with 10RM sets) were also examined in the laboratory conditions at months 0, 3, and 6. The exercise protocols were similar with regard to the total volume of work (loads x sets x reps), but differed with regard to the intensity and the length of rest between the sets (higher intensity and longer rest of 5 minutes vs. somewhat lower intensity but shorter rest of 2 minutes). Before and immediately after the protocols, maximal isometric force and electromyographic (EMG) activity of the leg extensors were measured and blood samples were drawn for determination of serum T, FT, C, and growth hormone (GH) concentrations and blood lactate. Both protocols before the experimental training period (month 0) led to large acute increases (p < 0.05-0.001) in serum T, FT, C , and GH concentrations, as well as to large acute decreases (p < 0.05-0.001) in maximal isometric force and EMG activity. However, no significant differences were observed between the protocols. Significant increases of 7% in maximal isometric force, 16% in the right leg 1RM, and 4% in the muscle CSA of the quadriceps femoris were observed during the 6-month strength-training period. However, both 3-month training periods performed with either the longer or the shorter rest periods between the sets resulted in similar gains in muscle mass and strength. No statistically significant changes were observed in basal hormone concentrations or in the profiles of acute hormonal responses during the entire 6-month experimental training period. The present study indicated that, within typical hypertrophic strength-training protocols used in the present study, the length of the recovery times between the sets (2 vs. 5 minutes) did not have an influence on the magnitude of acute hormonal and neuromuscular responses or long-term training adaptations in muscle strength and mass in previously strength-trained men.
对13名进行过休闲力量训练的男性进行了研究，以探讨急性和长期激素及神经肌肉对肥大力量训练的适应性。实验设计包括一个为期6个月的肥大力量训练期，其中包括两个独立的3个月训练期，采用交叉设计，训练方案为组间短休息（SR，2分钟）与长休息（LR，5分钟）相比较。在第0、3和6个月测量血清总睾酮（T）、游离睾酮（FT）和皮质醇（C）的基础激素浓度、腿部伸肌的最大等长力量、右腿1次重复最大值（1RM）、饮食分析以及通过磁共振成像（MRI）测量股四头肌的肌肉横截面积（CSA）。在第0、3和6个月的实验室条件下，还对用于腿部伸肌训练（腿举和10RM组深蹲）的两种肥大训练方案进行了研究。两种训练方案在总工作量（负荷×组数×重复次数）方面相似，但在强度和组间休息时间方面有所不同（高强度和5分钟的较长休息时间与稍低强度但2分钟的较短休息时间）。在训练方案前后，测量腿部伸肌的最大等长力量和肌电图（EMG）活动，并采集血样以测定血清T、FT、C和生长激素（GH）浓度以及血乳酸。在实验训练期（第0个月）之前，两种训练方案均导致血清T、FT、C和GH浓度大幅急性升高（p<0.05 - 0.001），以及最大等长力量和EMG活动大幅急性降低（p<0.05 - 0.001）。然而，两种训练方案之间未观察到显著差异。在为期6个月的力量训练期内，观察到最大等长力量显著增加7%，右腿1RM增加16%，股四头肌肌肉CSA增加4%。然而，无论组间休息时间是较长还是较短的两个3个月训练期在肌肉质量和力量方面的增加相似。在整个6个月的实验训练期内，基础激素浓度或急性激素反应曲线均未观察到统计学上的显著变化。本研究表明，在本研究中使用的典型肥大力量训练方案内，组间恢复时间的长短（2分钟与5分钟）对先前进行过力量训练的男性的急性激素和神经肌肉反应的幅度或肌肉力量和质量的长期训练适应性没有影响。
