Author and graduation date: Brenna KIELTY, May, 1999

Committee members: Patricia Patterson (Chair), Anthony Sucec, Tony Cherin

Thesis title: Validity and Reliability of the 20-meter Multistage Shuttle Test

The purpose of this study was to examine the validity and the reliability of the 20 meter shuttle test (20-MST) in female soccer athletes. Twenty-seven women (mean age = 23.63 + 4.76 years) performed 4 separate trials of the 20-MST within 3 weeks, on two different surfaces, grass and gym. This test required athletes to run between two cones positioned 20 meters apart, at a predetermined pace. The pace was set by a series of prerecorded "beeps" indicating when the athlete should have arrived at the originating cone. A lap was recorded every time the athlete completed a 20-meter length. The speed during the first minute was set at 8.5 km/hr and increased by .5 km/hr every minute thereafter. The test was terminated when the participant failed to reach the line two consecutive times within the time period or upon volitional exhaustion. VO2max was assessed on a Quinton Model 65 treadmill. The test began with a speed of 3 m.p.h for 3 minutes at 0% grade. Speed was then increased to 6 m.p.h. for 3 minutes at 0% grade. For the remainder of the test speed was increased to 7 m.p.h. with 2% increases in grade every minute thereafter. Test-retest reliability of the 20-MST was examined for laps completed, speed attained, and for predicted VO2max on both surfaces. In all cases reliability was very high with coefficients ranging from R = . 94 (95% C.I. .86 to .97) to R =.96 (95% C.I. .91 to .98). Validity coefficients comparing the number of laps run during the 20-MST with actual VO2max was r =.64 (95% C.I. = .35 to .82) on grass surface and r = .52 (95% C.I. =. 18 to .75) on a gym surface. Validity coefficients comparing speed attained during the 20-MST with actual VO2max were r =.72 (95% C.I. .47 to .86) on the grass surface and r = .56 (95% C.I. = .24 to .77) on the gym surface. Finally, validity coefficients comparing actual VO2max and predicted VO2max on a grass and a gym surface using the equation by Leger et al. (1988) were r =.72 (95% C.I. = .47 to .86) and r =.56 (95% C.I. = .24 to .77), respectively. Multiple regression using percent body fat, heart rate and either number of laps run or speed attained was employed to determine whether a new equation would possess higher validity. Only laps run and speed attained remained in the final equations. Since the new equations were univariate, correlations remained unchanged. Results of this study suggest that the 20-MST is a highly reliable field test but possesses only moderate validity. Future studies should be conducted employing larger samples to cross validate the new equation.

Click here to return to the Completed Master Degree Theses in Exercise Physiology Table of Contents.