Weston A R, Myburgh K H, Lindsay F H, Dennis S C, Noakes T D, Hawley J A
Department of Physiology, UCT Medical School, Observatory, South Africa.
Eur J Appl Physiol Occup Physiol. 1997;75(1):7-13. doi: 10.1007/s004210050119.
Skeletal muscle buffering capacity (beta m), enzyme activities and exercise performance were measured before and after 4 weeks of high-intensity, submaximal interval training (HIT) undertaken by six well-trained competitive cyclists [mean maximal oxygen consumption (VO2max) = 66.2 ml.kg-1.min-1]. HIT replaced a portion of habitual endurance training and consisted of six sessions, each of six to eight repetitions of 5 min duration at 80% of peak sustained power output (PPO) separated by 1 min of recovery. beta m increased from 206.6 (17.9) to 240.4 (34.1) mumol H+.g muscle dw-1.pH-1 after HIT (P = 0.05). PPO, time to fatigue at 150% PPO (TF150) and 40-km cycle time trial performance (TT40) all significantly improved after HIT (P < 0.05). In contrast, there was no change in the activity of either phosphofructokinase or citrate synthase. In addition, beta m correlated significantly with TT40 performance before HIT (r = -0.82, P < 0.05) and the relationship between change in beta m and change in TT40 was close to significance (r = -0.74). beta m did not correlate with TF150. These results indicate that beta m may be an important determinant of relatively short-duration (< 60 min) endurance cycling activity and responds positively to just six sessions of high-intensity, submaximal interval training.
对6名训练有素的竞技自行车运动员（平均最大摄氧量[VO2max]=66.2 ml·kg-1·min-1）进行为期4周的高强度次最大强度间歇训练（HIT）前后，测量了他们的骨骼肌缓冲能力（βm）、酶活性和运动表现。HIT取代了一部分习惯性耐力训练，包括6次训练，每次训练包含6至8次重复，每次持续5分钟，强度为峰值持续功率输出（PPO）的80%，每次重复之间间隔1分钟恢复时间。HIT后，βm从206.6（17.9）增加到240.4（34.1）μmol H+·g肌肉湿重-1·pH-1（P=0.05）。HIT后，PPO、150%PPO时的疲劳时间（TF150）和40公里计时赛成绩（TT40）均显著提高（P<0.05）。相比之下，磷酸果糖激酶或柠檬酸合酶的活性没有变化。此外，HIT前βm与TT40成绩显著相关（r=-0.82，P<0.05），βm变化与TT40变化之间的关系接近显著（r=-0.74）。βm与TF150不相关。这些结果表明，βm可能是相对短时间（<60分钟）耐力自行车运动的一个重要决定因素，并且对仅6次高强度次最大强度间歇训练有积极反应。
