You could be reading the full-text of this article now if you...

If you have access to this article through your institution,
you can view this article in

Comparison Between Hand and Electronic Timing of 40-yd Dash Performance in College Football Players

Mayhew, Jerry L1,2; Houser, Jeremy J3; Briney, Ben B1; Williams, Tyler B1; Piper, Fontaine C3,4; Brechue, William F5

Journal of Strength & Conditioning Research:
doi: 10.1519/JSC.0b013e3181c08860
Original Research

Mayhew, JL, Houser, JJ, Briney, BB, Williams, TB, Piper, FC, and Brechue, WF. Comparison between hand and electronic timing of 40-yd dash performance in college football players. J Strength Cond Res 24(2): 447-451, 2010-The purpose of this study was to determine the difference between hand and electronic timing of 40-yd dashes in college football players. National Collegiate Athletic Association Division II players (n = 59) were measured during a 40-yd sprint by electronic timing and simultaneously by 7 experienced hand timers using digital stopwatches. Electronic times were initiated by lifting the hand from a switch mat and stopped by the torso passing through an infrared beam. Hand timers initiated timing on first movement of the player from a 3-point stance. To establish performance and timing reliabilities, 32 players completed a second trial. Interrater reliability for hand timing was intraclass correlation coefficient (ICC) = 0.987 (p < 0.001). Five of the 7 timers did not differ significantly (p > 0.05) in their timing. The maximum difference among the hand timers on any given trial was 0.19 ± 0.14 seconds, with a 95% confidence interval (CI) of −0.08 to 0.41 seconds. Hand timing (4.85 ± 0.28 seconds) was significantly faster (p < 0.001) than electronic timing (5.16 ± 0.28 seconds), producing an average difference of 0.31 ± 0.07 seconds (6.0 ± 1.3%) and a 95% CI on the average difference of −0.44 to −0.18 seconds. The correlation between electronic timing and hand timing was ICC = 0.985 (p < 0.001). Practically speaking, electronic timing produces the best measurement of 40-yd dash speed, and using the hand timing produces consistently but significantly faster times.

Author Information

1Human Performance Laboratory, Truman State University, Kirksville, Missouri; 2Department of Physiology, A. T. Still University of Health Sciences, Kirksville, Missouri; 3Motor Control Laboratory, Truman State University, Kirksville, Missouri; 4Department of Anatomy, A. T. Still University of Health Sciences, Kirksville, Missouri; and 5Center for Physical Development Excellence, Department of Physical Education, United States Military Academy, West Point, New York

Address correspondence to Dr. Jerry L. Mayhew,

© 2010 National Strength and Conditioning Association