It has been shown in soccer that the repeated sprint ability (RSA)is essential in the physical performance of soccer(Dellal et al.2010).The literature,however, reports little field researches on the RSA in young soccer players reflecting the absence of a reference standardized protocol to assess their ability to repeat sprints(Girard et al.2011).Therefore,the aim of this study was to develop and validate an RSA test protocol in young soccer players and examine its reliability in this context.It was hypothesized that an RSA protocol with a logical validity based on match time-motion analysis with seven 15-meter sprints and 25seconds of active recovery between sprints would be appropriate for the assessment of the ability to repeat sprints in young soccer players. Methods: Seventeen Under-15 soccer players participated in the study.All subjects have performed in random order 3 RSA tests:2 seven 15-meter test with 25sec of active recovery and a six 40-meter(20-meter/20- meter shuttle)with 20seconds of passive recovery Results: Measurements of the mean total time, best time and rating of perceived exertion of each test showed high reliability in terms of ICC(RSAmean:0.93, RSAbest:0.80, and RPE: 0.83),low CV(RSAmean:1.18,RSAbest:1.97, and RPE:11.14) and the small effect size for the test/retest of 7x15m RSA testing trials(RSAmean:- 0.08,RSAbest: 1.17, and RPE:-0.06).Furthermore, the RSA test`s construct validity was confirmed by its ability to discriminate between goalkeepers and field players(RSAmean;p=0.03 and RSAbest;p=0.02). Discussion: Reliability results showed that the mean total time, best sprint time and the RPE were highly reliable.The sprint decrement, mean heart rate, and blood lactate measures showed lower reliability. The low reliability of fatigue through RSAdec measurements is probably related to the fact that rather than being measured, fatigue is derived from data that have their own inherent variability.In the present study we focused(for construct validity)on differentiation according to the players` field positions. Indeed, analyses of the mean total time and best time in the present protocol were able to discriminate between field players and goalkeepers which support the construct validity of this RSA protocol in young soccer players.The correlation between the total mean times in the 7x15m and 6x40m tests was moderate and not statistically significant. This lack of correlation may be due to the sprinting distance/time,sprint`s form or the difference in the nature of recovery.In conclusion,the RSA test with logical validity developed here has also a construct validity and showed sufficient reliability to assess the repeated-sprint ability in young soccer players.
© Copyright 2012 17th Annual Congress of the European College of Sport Science (ECSS), Bruges, 4. -7. July 2012. Veröffentlicht von Vrije Universiteit Brussel. Alle Rechte vorbehalten.