Chaouachi Anis, Haddad Monoem, Castagna Carlo, Wong Del P, Kaouech Fathi, Chamari Karim, Behm David G
Tunisian Research Laboratory, Sports Performance Optimization, National Center of Medicine and Science in Sports, Tunis, Tunisia.
Pediatr Exerc Sci. 2011 Feb;23(1):136-50. doi: 10.1123/pes.23.1.136.
The objective of this study was to examine the response and recovery to a single set of maximal, low and high angular velocity isokinetic leg extension-flexion contractions with boys. Sixteen boys (11-14 yrs) performed 10 isokinetic contractions at 60°.s-1 (Isok60) and 300°.s-1 (Isok300). Three contractions at both velocities, blood lactate and ratings of perceived exertion were monitored pretest and at 2, 3, 4, and 5 min of recovery (RI). Participants were tested in a random counterbalanced order for each velocity and recovery period. Only a single contraction velocity (300°.s-1 or 60°.s-1) was tested during recovery at each session to remove confounding influences between the recovery intervals. Recovery results showed no change in quadriceps' power at 300°.s-1, quadriceps' power, work and torque at 60°.s-1 and hamstrings' power and work with 60°.s-1. There was an increase during the 2 min RI in hamstrings' power, work and torque and quadriceps' torque with isokinetic contractions at 300°.s-1 suggesting a potentiating effect. Performance impairments during recovery occurred for the hamstrings torque at 60°.s-1 and quadriceps work with 300°.s-1. In conclusion, 10 repetitions of either low or high velocity isokinetic contractions (Isok60 or Isok300) resulted in full recovery or potentiation of most measures within 2 min in boys. The potentiation effect predominantly occurred following the hamstrings Isok300 which might be attributed to a greater agonist-antagonist torque balance and less metabolic stress associated with the shorter duration higher velocity contractions.
本研究的目的是检验男孩进行一组最大、低角速度和高角速度等速腿屈伸收缩后的反应和恢复情况。16名男孩（11 - 14岁）以60°·s⁻¹（Isok60）和300°·s⁻¹（Isok300）的速度进行了10次等速收缩。在两种速度下各进行3次收缩，在预测试时以及恢复（RI）的2、3、4和5分钟时监测血乳酸和主观用力程度评级。针对每种速度和恢复阶段，参与者按照随机平衡顺序进行测试。在每次恢复阶段仅测试单一收缩速度（300°·s⁻¹或60°·s⁻¹），以消除恢复间隔之间的混杂影响。恢复结果显示，在300°·s⁻¹时股四头肌力量无变化，在60°·s⁻¹时股四头肌力量、功和扭矩以及在60°·s⁻¹时腘绳肌力量和功无变化。在300°·s⁻¹等速收缩时，在2分钟的恢复期间，腘绳肌力量、功和扭矩以及股四头肌扭矩有所增加，表明存在增强效应。在恢复过程中，60°·s⁻¹时腘绳肌扭矩以及300°·s⁻¹时股四头肌功出现了表现受损情况。总之，10次低速或高速等速收缩（Isok60或Isok300）会使男孩在2分钟内大多数指标完全恢复或增强。增强效应主要发生在腘绳肌Isok300之后，这可能归因于更大的主动肌 - 拮抗肌扭矩平衡以及与较短持续时间、较高速度收缩相关的代谢压力较小。
