Watts P, Newbury V, Sulentic J
Exercise Science Laboratory, Northern Michigan University, Morquette, USA.
J Sports Med Phys Fitness. 1996 Dec;36(4):255-60.
Modern rock climbers stress the importance of hand-to-rock contact strength as a factor for success in competitive sport climbing events, however, the degree of handgrip fatigue that occurs during difficult climbing and the time course of recovery from fatigue have not been previously described. The purpose of this study was to characterize the nature of handgrip fatigue that results from difficult continuous climbing until a fall occurs.
Eleven expert-level rock climbers (age = 28.7 +/- 4.5 years) volunteered to climb continuous laps over a pre-set competition-type route on an indoor modular climbing wall until a fall occurred. The route difficulty (YDS rating of 5.12 a) was near the limit of each subject's "on-sight" lead climbing ability and placed an emphasis on physically difficult movements. "On-sight" refers to a climbing style where the climber ascends the route on the first try without falls and without prior viewing or information about the route. Practice was allowed to enable each subject to master the individual technical movements of the route. Fingertip blood samples were obtained 10 min pre-climb, at post-climb, and at 5-, 10-, and 20-min recovery and analyzed for lactate. Maximum handgrip force in Newtons was determined via dynamometry for each hand and averaged for pre-climb, post-climb, and 5-, 10-, and 20-min recovery periods. Right handgrip endurance, defined as the time that the dominant hand handgrip force could be sustained above 70 percent of handgrip strength, was determined pre-climb, post-climb, and at 20-min recovery.
Mean climbing time during testing was 12.9 +/- 8.5 min for 2.8 +/- 2.2 laps over the route. Data among measurement times were analyzed using a repeated measures ANOVA with Newman-Keuls post hoc tests. Handgrip strength decreased by 22 percent and handgrip endurance decreased by 57 percent from pre-climb to post-climb and both remained depressed after 20 minutes of resting recovery. The pre-climb blood lactate of 1.4 +/- 0.8 mmol.l-1 significantly increased to 6.1 +/- 1.4 mmol.l-1 at post-climb and remained elevated (2.3 +/- 0.8 mmol.l-1) at 20-min recovery. Percent decreases in handgrip strength were significantly correlated with climbing time (R = 0.70), number of laps completed (R = 0.70), and blood lactate (R = 0.76). Percent decreases in handgrip endurance were significantly correlated with climbing time (R = 0.70) and number of laps completed (R = 0.80), but not with blood lactate (R = 0.56).
It was concluded that handgrip strength and handgrip endurance decrease with continuous difficult rock climbing and remain depressed after 20 minutes of resting recovery. It also appears that handgrip strength recovers at a faster rate than handgrip endurance.
现代攀岩者强调手与岩石接触强度作为竞技攀岩比赛成功因素的重要性，然而，此前尚未描述在困难攀爬过程中发生的握力疲劳程度以及从疲劳中恢复的时间进程。本研究的目的是描述因持续困难攀爬直至跌落而导致的握力疲劳的性质。
11名专家级攀岩者（年龄 = 28.7 ± 4.5岁）自愿在室内模块化攀岩墙上按照预先设定的比赛类型路线连续攀爬多圈，直至跌落。路线难度（YDS等级为5.12a）接近每个受试者“一次通过”领先攀爬能力的极限，并强调身体上困难的动作。“一次通过”指的是一种攀岩方式，即攀岩者在第一次尝试时不跌落且没有事先查看或了解路线信息的情况下攀登路线。允许进行练习以使每个受试者掌握路线的各个技术动作。在攀爬前10分钟、攀爬后以及恢复5分钟、10分钟和20分钟时采集指尖血样并分析乳酸含量。通过测力计确定每只手以牛顿为单位的最大握力，并计算攀爬前、攀爬后以及恢复5分钟、10分钟和20分钟期间的平均值。右手握力耐力定义为主手的握力能够维持在握力强度的70%以上的时间，在攀爬前、攀爬后以及恢复20分钟时进行测定。
测试期间的平均攀爬时间为12.9 ± 8.5分钟，完成2.8 ± 2.2圈。使用重复测量方差分析及纽曼 - 基尔斯事后检验对测量时间之间的数据进行分析。从攀爬前到攀爬后，握力强度下降了22%，握力耐力下降了57%，并且在休息恢复20分钟后两者仍处于较低水平。攀爬前的血乳酸水平为1.4 ± 0.8 mmol·l-1，在攀爬后显著增加至6.1 ± 1.4 mmol·l-1，在恢复20分钟时仍保持在较高水平（2.3 ± 0.8 mmol·l-1）。握力强度的下降百分比与攀爬时间（R = 0.70）、完成的圈数（R = 0.70）和血乳酸（R = 0.76）显著相关。握力耐力的下降百分比与攀爬时间（R = 0.70）和完成的圈数（R = 0.80）显著相关，但与血乳酸（R = 0.56）无关。
得出的结论是，持续困难的攀岩会导致握力强度和握力耐力下降，并且在休息恢复20分钟后仍处于较低水平。握力强度似乎比握力耐力恢复得更快。
