School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's Newfoundland, A1C 5S7, Canada.
Eur J Appl Physiol. 2014 Apr;114(4):825-35. doi: 10.1007/s00421-013-2809-2. Epub 2014 Jan 8.
To determine if prepubescent and adult males have similar fatigue profiles following high and lower intensity knee extensions.
Ten male children and ten adults completed two sessions of three sets of high repetition (17 typical muscle endurance training) high repetition (High RM) or low repetition (seven typical strength training) maximum (Low RM) dynamic knee extensions. Voluntary and evoked contractile properties, heart rate (HR), and rating of perceived exertion (RPE) were assessed before and after each knee extension RM.
Knee extension RM measures revealed that boys performed more (children set 2, 6.7 ± 0.5; set 3, 5.7 ± 0.5 vs. adult set 2, 5.2 ± 0.4; set 3, 3.5 ± 0.5; P < 0.001) repetitions, had a faster (children 39.9 ± 8.6 vs. adult 9.4 ± 3.7 bpm; P < 0.001) HR recovery and lower (6.4 ± 0.43; P < 0.001) RPE compared to adults (8.0 ± 0.4). Post-knee extension measures also revealed a smaller MVC force decrement (P < 0.001) with boys (94.3 % ± 6.1 vs. 76.3 % ± 4.1). Unlike adults, there were no significant decrements to children's evoked contractile properties or EMG. The greater boys' antagonist activation (children 125.7 % ± 9.2 vs. adult: 103.5 % ± 6.7; P < 0.001) post-knee extension would suggest muscle coordination changes as a primary mechanism for MVC force decrements. The lower RPE and similar agonist EMG activity may also indicate an inability of boys to perceive or produce a maximal effort.
Independent of High or Low RM knee extensions, boys had greater neuromuscular fatigue resistance and recovered faster than adults.
确定青春期前和成年男性在进行高强度和低强度膝关节伸展后是否具有相似的疲劳特征。
10 名男性儿童和 10 名成年男性完成了两次三次高重复（17 次典型的肌肉耐力训练）高重复（High RM）或低重复（7 次典型的力量训练）最大重复（Low RM）的膝关节伸展运动。在每次膝关节伸展 RM 前后，评估了自愿和诱发的收缩性能、心率（HR）和感知用力（RPE）。
膝关节伸展 RM 测量结果显示，男孩完成的重复次数更多（儿童组 2，6.7 ± 0.5；组 3，5.7 ± 0.5 与成年组 2，5.2 ± 0.4；组 3，3.5 ± 0.5；P < 0.001），心率恢复更快（儿童 39.9 ± 8.6 与成年 9.4 ± 3.7 bpm；P < 0.001），RPE 更低（6.4 ± 0.43；P < 0.001）与成年人（8.0 ± 0.4）相比。膝关节伸展后的测量结果还显示，男孩的最大肌力下降幅度较小（P < 0.001）（94.3% ± 6.1 与 76.3% ± 4.1）。与成年人不同的是，儿童的诱发收缩性能或肌电图没有明显下降。膝关节伸展后，男孩的拮抗肌激活程度更大（儿童 125.7% ± 9.2 与成人：103.5% ± 6.7；P < 0.001），这表明肌肉协调变化是最大肌力下降的主要机制。较低的 RPE 和相似的激动剂肌电图活动也可能表明男孩无法感知或产生最大努力。
无论进行高或低 RM 膝关节伸展运动，男孩的神经肌肉疲劳抵抗力都更强，恢复速度也比成年人更快。
