Mann J Bryan, Ivey Pat J, Brechue William F, Mayhew Jerry L
Departments of 1Athletic Performance and 2Physical Therapy, University of Missouri, Columbia, Missouri; 3Department of Physiology, A. T. Still University of Health Sciences, Kirksville, Missouri; and 4Exercise Science Department, Exercise Science Program, Truman State University, Kirksville, Missouri.
J Strength Cond Res. 2015 Jun;29(6):1509-14. doi: 10.1519/JSC.0000000000000941.
The 40-yd sprint is the premier event for evaluating sprint speed among football players at all competitive levels. Some questions remain concerning the validity of hand timing compared with electronic timing, as well as the lack of assessment and reliability of each method. The purpose of this study was to evaluate the validity of hand timing by experienced and novice timers compared with electronic timing and to establish the reliability and smallest worthwhile difference (SWD) of each method for the 40-yd sprint. National Collegiate Athletic Association (NCAA) Division I college football players (n = 81) ran two 40-yd sprint trials, with each being timed electronically (touch pad start and infrared beam stop) and with hand-held stopwatches by 2 experienced and 4 novice timers. There was no significant difference between trials timed electronically or by experienced and novice timers. Hand timing (experienced = 4.90 ± 0.34 seconds; novice = 4.86 ± 0.33 seconds) produced a significantly faster 40-yd sprint time than electronic timing (5.12 ± 0.35 seconds) by 0.22 ± 0.07 and 0.26 ± 0.08 seconds, respectively. Relative reliability was extremely high for all comparisons with intraclass correlation coefficient >0.987. The SWD was 0.12 seconds with electronic timing and 0.14 seconds with hand timing. In conclusion, hand timing produces faster sprint times than electronic timing in college football players, independent of timer experience. Repeated 40-yd sprint trials have high relative reliability regardless of timing method. A meaningful change in 40-yd sprint performance is dependent on timing method used.
40码冲刺跑是评估各级别足球运动员冲刺速度的首要项目。与电子计时相比，手计时的有效性以及每种方法的评估和可靠性仍存在一些问题。本研究的目的是评估经验丰富和新手计时员的手计时与电子计时相比的有效性，并确定40码冲刺跑每种方法的可靠性和最小有意义差异（SWD）。美国国家大学体育协会（NCAA）一级大学橄榄球运动员（n = 81）进行了两次40码冲刺跑测试，每次测试都通过电子计时（触摸板启动和红外光束停止）以及由2名经验丰富的计时员和4名新手计时员使用手持秒表计时。电子计时、经验丰富的计时员计时和新手计时员计时之间没有显著差异。手计时（经验丰富的计时员 = 4.90 ± 0.34秒；新手计时员 = 4.86 ± 0.33秒）得出的40码冲刺跑时间分别比电子计时（5.12 ± 0.35秒）快0.22 ± 0.07秒和0.26 ± 0.08秒。所有比较的组内相关系数>0.987，相对可靠性极高。电子计时的SWD为0.12秒，手计时的SWD为0.14秒。总之，在大学橄榄球运动员中，无论计时员经验如何，手计时得出的冲刺跑时间比电子计时更快。无论计时方法如何，重复进行40码冲刺跑测试都具有较高的相对可靠性。40码冲刺跑成绩的有意义变化取决于所使用的计时方法。
