Difference In 40-Yd Dash And Pro-Agility Times On Artificial Turf And Natural Grass

Abstract

Artificial turf has become the state of the art for the playing surface in football. Anecdotal evidence suggests that artificial turf may enhance sprint speed, but there seems to be little scientific data to support this claim. Purpose: The purpose of this study was to determine the difference in 40-yd dash and pro-agility time on artificial turf (AT) and natural grass (NG). Methods: Red-shirt freshmen Div II college football players (n = 24) performed two trials each of a 40-yd dash and pro-agility run on each surface. The first test series was performed on AT, and the second test series was performed a week later on NG. Players wore shorts, T-shirts, and regulation football cleats. Two sprints were timed by an electronic timing system (ET) and by 2 hand timers (HT). Agility was timed on each surface by 2 hand timers; the average of the two timers was used. Results: Intraclass correlation coefficients (ICC) for repeated trials ranged from 0.80 (pro-agility) to 0.99 (ET 40-yd dash). There was no significant difference in 40-yd dash times between ET on turf (5.39 ± 0.30 s) and on NG (5.38 ± 0.33 s). HT 40-yd dashes (AT: 5.12 ± 0.30 s, NG: 5.16 ± 0.30s) were significantly faster than ET 40-yd dashes (AT: 5.39 ± 0.30 s, NG: 5.38 ± 0.33 s) on both surfaces. The difference between HT and ET on turf (0.28 ± 0.8 s) was significantly greater than the difference on NG (0.22 ± 0.05 s), and the differences were nonsignificantly correlated (ICC = 0.21). The relationship between the difference between HT and ET vs the criterion ET was greater for NG (r = 0.65, p < 0.01) than for AT (r = 0.16, p = 0.35). Pro-agility times were significantly faster on turf (4.64 ± 0.28 s) than on grass (4.76 ± 0.32 s). Conclusion: Sprint speed is no faster on AT than on NG, but cutting speed may be faster on AT. Based on the difference between HT and ET, hand-timers may disproportionately anticipate players to be faster on AT than on NG. Furthermore, the slower a player is on NG, the faster his time was anticipated to be by HT. Practical Application: Artificial turf may not enhance straight-ahead speed but may aid change-of-direction speed in college football players. Anticipation of straight-ahead speed by hand-timers may cause a slightly faster recording of 40-yd dash speed when sprints are performed on AT.