College of Human Kinesiology, Shenyang Sport University, 36 Jinqiansong East Road Sujiatun District, Shenyang, 110102, Liaoning, China.
Mountaineering Management Center, General Administration of Sport of China, Beijing, China.
Eur J Appl Physiol. 2019 Mar;119(3):791-800. doi: 10.1007/s00421-018-04070-w. Epub 2019 Jan 28.
The purpose of this study was to investigate the changes in blood lactate concentration (BL) and muscle activity patterns during a 15-m speed climbing competition that consisted of ten consecutive climbing actions on a standardized artificial wall in trained rock climbers.
Twelve trained rock climbers participated in this study. Surface electromyography (sEMG) and video signals were synchronized and recorded during climbing. The blood lactate was also tested 3 min after completing the climb.
The average climbing time was 8.1 ± 2.1 s for the 15-m speed climb across all subjects, accompanied by a BL of 7.6 ± 1.9 mmol/L. The climbing speed and power firstly increased and then slightly decreased relative to peak value during the 15-m speed climbing. The results showed there was a positive correlation between the BL and the climbing time, r = 0.59, P = 0.043. The sEMG showed the flexor digitorum superficialis (FDS) electric activity was the highest, followed by the biceps brachii (BB) and latissimus dorsi. The instantaneous median frequency of sEMG of FDS and BB significantly decreased during the 15-m speed climbing. All the participants showed the higher sEMG RMS (%) in the terminal phase than that in the initial phase, especially with a greater increase in the left upper limbs. However, the lower limbs muscles presented no significant changes in the sEMG amplitude during climbing.
The FDS and BB play an important role in completing the 15-m speed climbing. The median frequency of arm EMG decreased more than that of legs, suggesting more fatigue. The blood lactate concentration increases in the current study suggest that a certain amount of glycolysis supplies energy in completing 15-m speed rock climbing. Based on the current data, it is suggested that muscular endurance of FDS and BB muscles in upper limbs should be improved for our climbers in this study.
本研究旨在探讨在标准化人工壁上连续进行十次攀爬动作的 15 米速度攀岩比赛中，血液乳酸浓度 (BL) 和肌肉活动模式的变化，研究对象为 12 名有训练的攀岩者。
研究中同步记录了参与者在攀爬过程中的表面肌电图 (sEMG) 和视频信号，同时在攀爬结束后 3 分钟测试血液乳酸。
所有受试者完成 15 米速度攀爬的平均时间为 8.1±2.1 秒，BL 为 7.6±1.9mmol/L。在 15 米速度攀爬过程中，攀爬速度和功率先增加，然后相对于峰值略有下降。结果显示，BL 与攀爬时间呈正相关，r=0.59，P=0.043。sEMG 显示，指浅屈肌 (FDS) 的电活动最高，其次是肱二头肌 (BB) 和背阔肌。在 15 米速度攀爬过程中，FDS 和 BB 的 sEMG 瞬时中值频率显著降低。所有参与者在终端阶段的 sEMG RMS(%)均高于初始阶段，尤其是左上肢的增加更为明显。然而，在攀爬过程中，下肢肌肉的 sEMG 振幅没有明显变化。
FDS 和 BB 在完成 15 米速度攀岩中发挥重要作用。手臂 EMG 的中值频率下降幅度大于腿部，表明疲劳程度更高。本研究中血液乳酸浓度的升高表明，一定量的糖酵解为完成 15 米速度攀岩提供能量。根据目前的数据，建议本研究中的攀岩者应提高上肢 FDS 和 BB 肌肉的肌肉耐力。
