Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, CANADA.
Post-Graduate Program in Movement Science, Laboratory of Physiology and Sport Performance (LAFIDE), São Paulo State University (UNESP), Bauru, SP, BRAZIL.
Med Sci Sports Exerc. 2021 Feb 1;53(2):413-420. doi: 10.1249/MSS.0000000000002482.
The present study investigated the recovery of performance and neuromuscular fatigue after cycling repeated sprints.
Ten participants performed two sessions of repeated sprints (one session: 10 × 10-s sprints, 30-s recovery) separated by 24 h (R24-S1 and R24-S2) and two sessions separated by 48 h (R48-S1 and R48-S2). The recovery condition (i.e., 24 or 48 h) was randomized and separated by 1 wk. All sessions were performed on a recumbent bike, allowing minimal delay between sprints termination and neuromuscular measurements. Neuromuscular function of knee extensors (neuromuscular assessment [NMA]) was assessed before sessions (presession), after the fifth sprint (midsession), and immediately after (postsession). Before sessions, baseline NMA was also carried out on an isometric chair. The NMA (bike and chair) was composed of maximal voluntary contraction (MVC) of knee extension and peripheral neuromuscular stimulation during the MVC and on relaxed muscle.
The sprints performance was not significantly different between sessions and did not presented significant interaction between recovery conditions. MVC was significantly lower at R24-S2 compared with R24-S1 (-6.5% ± 8.8%, P = 0.038) and R48-S2 (-5.6% ± 8.2%, P = 0.048), whereas resting potentiated high-frequency doublet (Db100) was lower at R24-S2 compared with R24-S1 (-10.4 ± 8.3, P = 0.01) (NMA on chair). There were significant reductions in MVC (>30%, P < 0.001) and Db100 (>38%, P < 0.001) from pre- to postsession in all sessions, without significant interactions between recovery conditions (NMA on bike).
Cycling repeated sprints induce significant fatigue, particularly at the peripheral level, which is fully restored after 48 h, but not 24 h, of recovery. One versus two days of recovery does not affect neuromuscular fatigue appearance during cycling repeated-sprint sessions.
本研究旨在探讨周期性自行车重复冲刺后运动表现和神经肌肉疲劳的恢复情况。
10 名参与者分别进行两次重复冲刺（一次：10 个 10 秒冲刺，30 秒恢复期），两次之间间隔 24 小时（R24-S1 和 R24-S2），或间隔 48 小时（R48-S1 和 R48-S2）。恢复期（即 24 或 48 小时）随机分配，并间隔 1 周。所有的冲刺测试均在卧式自行车上进行，以确保冲刺结束和神经肌肉测量之间的最小延迟。在测试前（pre-session）、第五次冲刺后（mid-session）和即刻（post-session）对膝关节伸肌的神经肌肉功能（神经肌肉评估[NMA]）进行评估。在测试前，还在等长椅上进行基线 NMA。NMA（自行车和椅子）由膝关节伸展的最大自主收缩（MVC）和 MVC 期间以及肌肉放松时的外周神经肌肉刺激组成。
冲刺表现测试在不同的测试中无显著差异，恢复期也无显著的交互作用。与 R24-S1（-6.5%±8.8%，P=0.038）和 R48-S2（-5.6%±8.2%，P=0.048）相比，R24-S2 时的 MVC 明显降低，而在 R24-S2 时的休息增强高频双脉冲（Db100）比 R24-S1 时低（-10.4±8.3，P=0.01）（椅子上的 NMA）。在所有测试中，从测试前到即刻后，MVC（>30%，P<0.001）和 Db100（>38%，P<0.001）均显著降低，恢复期无显著的交互作用（自行车上的 NMA）。
周期性自行车重复冲刺会导致明显的疲劳，尤其是在周围水平，48 小时的恢复期可完全恢复，但 24 小时的恢复期则无法完全恢复。恢复期为 1 天或 2 天并不影响周期性自行车重复冲刺测试中神经肌肉疲劳的出现。
