This is the first study to test 3 popular field tests (Yo-Yo IR1, MSFT, and Hoff test) for direct validity in male youth soccer players within the same research design.
The results of this study are in-line with those of previous studies that examined the direct validity of the Yo-Yo IR1 in male and female soccer players (2). Also, the very large correlation (r = 0.73, p = 0.003, 95%CI 0.68-0.83) found between HIA and Yo-Yo IR1 performances is similar to that reported by Castagna et al. (13) for male young soccer players (r = 0.77, p < 0.001) and by Krustrup et al. (29,30) for adult male (r = 0.71, p < 0.05) and female (r = 0.76, p < 0.05) soccer players. However, in contrast to previous studies, no significant relationship was observed between TD and Yo-Yo IR1 (r = 0.42, p = 0.14, 95%CI 0.31-0.53) (13,29,30).
This study addressed for the first time the direct validity of MSFT and Hoff test in young male soccer players. The MSFT was significantly related to distances covered in several activity categories showing a magnitude of effects ranging from large to very large (24) (Table 2). In contrast to the Yo-Yo IR1, the MSFT performance was largely related to TD (r = 0.62, p = 0.02, 95%CI 0.52-0.72). However, no significant difference (p > 0.05) was found between correlation coefficients of Yo-Yo IR1 and MSFT for the TD covered. This finding may be considered as a consequence of the almost nearly perfect correlation (r = 0.89, p < 0.0001, 95%CI 0.78-0.93) found between MSFT and Yo-Yo IR1 performance in this study.
In light of the finding of this study, the MSFT and Yo-Yo IR1 may be considered as similar tests (i.e., 79% common variance) for young elite male soccer players of the age (14-15 years) considered here. Consequently, the MSFT and Yo-Yo IR1 may be used interchangeably to track the soccer-specific fitness of young male players in field conditions.
Despite having potential for a higher logical validity because it involves ball dribbling throughout the test, the Hoff test showed only a limited association with match activities when compared to MSFT and Yo-Yo IR1. Indeed the Hoff test was only related to the distance covered during the match with sprinting (r = 0.70, p = 0.04, 95%CI 0.68-0.72), with the magnitude of the correlation coefficient being consistent with those reported for the same match activity in the MSFT and Yo-Yo IR1 comparisons. The reason for that limited relevance for soccer shown by the Hoff test is difficult to be explained with this research design. However, the low relative (ICC = 0.68) and absolute (CV = 18.2) reliability reported in this study may suggest a limited application of the Hoff test for the performance assessment of young male soccer players' aerobic fitness.
The main problem with correlation studies is that the value of correlation is sensitive to sample homogeneity (23). However, the generalization of the findings of this study may be warranted by the stratified random sampling undertaken for determining the players' group. Furthermore, the data reported here for Yo-Yo IR1 and MSFT are in line with those found by Castagna et al. (13) and Williford et al. (46) in soccer players of a similar competitive level and age, respectively. Additionally, the average match distance covered by players was similar to that previously reported in studies addressing male youth soccer players of similar characteristics (i.e., age, experience and competitive level) (8,13). Furthermore, similarities with previously published studies on male youth soccer were found for cardiovascular stress (i.e., mean HR) (41). Conservation of HIA between halves was found despite a significant decrement of TD and MIR across halves, a finding in line with those of previously published papers (8,13), thus further supporting the suggested competitive “sparing behavior” reported originally by Castagna et al. (8). As a consequence of these similarities, in terms of physical match performance and field-test performance, the population of male youth soccer players used in this study may be considered as being representative of age, training, and competitive-level soccer players. Consequently, the external validity of the finding of this study is warranted (12).
The findings of this study clearly demonstrate that aerobic performance, as determined by commonly used field tests, is related to physical match performance in young male soccer players. This provides further evidence to the relevance of aerobic fitness per se in male youth soccer (39,40). Consequently, aerobic fitness should be collated in the training strategies attempting to develop the physical preparedness of young soccer players (13,27,41).
The associations resulting between field-test performance and match physical performance demonstrate that the Yo-Yo IR1 and MSFT may be regarded as relevant tests to evaluate endurance in young soccer players. However, the magnitude of the effect although ranging between large to very large according to the definition provided by Hopkins (24), the corresponding ES of the relationship, assumed as coefficient of determination (r2), was above the critical value of 0.50 only in 4 of the 8 significant preplanned correlations (42). Furthermore, the highest value did not reach 60% of shared variance. Although the specificity of this test should be interpreted with caution (i.e., r2 = 0.38-0.58), the direct validity was warranted by the findings of this study (42). It could be speculated that new soccer-specific tests are to be established to more closely describe physical demands of matches. In this regard, field tests should more closely mimic match activity pattern and must thus be based on sound match and time motion analysis procedures (6). Because of the interest and relevance of this issue, future studies are warranted.
The results of this study showed that the Yo-Yo IR1 and MSFT being strongly associated (i.e., r = 0.89, p < 0.0001) and similarly related to match physical performance (see Table 2) may be considered as being interchangeable. This peculiarity may suggest the use of these "beep tests" (i.e., audio cue guided tests) depending on the preparation moment of the season. Coaches and strength conditioning professionals may use the MSFT in the first stages of their fitness-training program because its protocol involves lower starting speeds (11). On the other hand, the Yo-Yo IR1 may be implemented when players are more aerobically fit because it considers starting speeds, although repeated for a limited number of bouts and with frequent recovery time (i.e., 10 seconds every 40 m), that very often correspond to the maximal speed attained at exhaustion during the MSFT. An added value of the Yo-Yo IR1 lies in the limited amount of time that is usually required (i.e., 6.21 minutes) in this population of young male soccer players (13). This suggests the Yo-Yo IR1 to be a field test that is easy to implement when limited time can be devoted to testing (i.e., during the competitive season) (2,29).
Interestingly, the Hoff test, although involving an exercise mode relevant to soccer (i.e., ball dribbling) possessed only a limited association with physical match performance (i.e., sprinting) and no significant relationship with the other field tests. However, the emerged association with match sprinting distance was similar to those shown by Yo-Yo IR1 and MSFT (p > 0.05). As a consequence of the required labor time necessary to set up the Hoff test track, the limited number of players that may be reasonably tested with this course at a time and the poor reliability shown by this test in this study, the use of the Hoff test is discouraged.
This project was fully financed by the Federazione Sammarinese Giuoco Calcio (FSCG, San Marino). We would like to thank Emilio Cecchini and Marco Giovannelli for their valuable help in collecting the data and in the organization of the practical aspect of this research. We extend our warm thanks to the enthusiastic availability of all the coaches and players of the FSGC.
1. Bangsbo, J. Fitness Training in Football-a Scientific Approach
. Bagsværd, Denmark: HO+Storm, 1994.
2. Bangsbo, J, Iaia, FM, and Krustrup, P. The Yo-Yo intermittent recovery test: A useful tool for evaluation of physical performance in intermittent sports. Sports Med
38: 37-51, 2008.
3. Barbero-Alvarez, JC, Coutts, A, Granda, J, Barbero-Alvarez, V, and Castagna, C. The validity and reliability of a global positioning satellite system device to assess speed and repeated sprint ability (RSA) in athletes. J Sci Med Sport
13: 232-235, 2010.
4. Boddington, MK, Lambert, MI, and Waldeck, MR.Validity of a 5-meter multiple shuttle run Test for assessing fitness of women field Hockey players. J Strength Cond Res
18: 97-100, 2004.
5. Bravo, DF, Impellizzeri, FM, Rampinini, E, Castagna, C, Bishop, D, and Wisløff, U. Sprint vs. interval training in football. Int J Sports Med
29: 668-674, 2008.
6. Carling, C, Bloomfield, J, Nelsen, L, and Reilly, T. The role of motion analysis in elite soccer: Contemporary performance measurement techniques and work rate data. Sports Med
38: 839-862, 2008.
7. Castagna, C, Abt, G, and D'Ottavio, S. Competitive-level differences in Yo-Yo intermittent recovery and 12 min run test performance in soccer referees. J Strength Cond Res
19: 805-809, 2005.
8. Castagna, C, D'Ottavio, S, and Abt, G. Activity profile of young soccer players during actual match play. J Strength Cond Res
17: 775-780, 2003.
9. Castagna, C, Impellizzeri, F, Cecchini, E, Rampinini, E, and Alvarez, JC. Effects of intermittent-endurance fitness on match performance in young male soccer players. J Strength Cond Res
23: 1954-1959, 2009.
10. Castagna, C, Impellizzeri, FM, Belardinelli, R, Abt, G, Coutts, A, Chamari, K, and D'Ottavio, S. Cardiorespiratory responses to Yo-Yo intermittent endurance test in nonelite youth soccer players. J Strength Cond Res
20: 326-330, 2006.
11. Castagna, C, Impellizzeri, FM, Chamari, K, Carlomagno, D, and Rampinini, E. Aerobic fitness and yo-yo continuous and intermittent tests performances in soccer players: A correlation study. J Strength Cond Res
20: 320-325, 2006.
12. Castagna, C, Impellizzeri FM, Rampinini, E, D'Ottavio, S, and Manzi, V. The Yo-Yo intermittent recovery test in basketball players J Sci Med Sport
11: 202-208, 2008.
13. Castagna, C, Impellizzeri, I, Cecchini, E, Rampinini, E, and Barbero Alvarez, JC. Effects of intermittent-endurance fitness on match performance in young male soccer players. J Strength Cond Res
14. Chamari, K, Hachana, Y, Kaouech, F, Jeddi, R, Moussa-Chamari, I, and Wisløff, U. Endurance training and testing with the ball in young elite soccer players. Br J Sports Med
39: 24-28, 2005.
15. Cohen, J. Statistical Power Analysis for the Behavioral Sciences
. Hillsdale, NJ: Lawrence Erlbaum Associates, 1988.
16. Coutts, AJ and Duffield, R. Validity and reliability of GPS devices for measuring movement demands of team sports
. J Sci Med Sport
17. Edgecomb, SJ and Norton, KI. Comparison of global positioning and computer-based tracking systems for measuring player movement distance during Australian football. J Sci Med Sport
9: 25-32, 2006.
18. Esposito, F, Impellizzeri, FM, Margonato, V, Vanni, R, Pizzini, G, and Veicsteinas, A. Validity of heart rate as an indicator of aerobic demand during soccer activities in amateur soccer players. Eur J Appl Physiol
93: 167-172, 2004.
19. Gore, CJ, ed. Physiological Tests for Elite Athletes
. Champaign, IL: Human Kinetics, 2000.
20. Helgerud, J, Engen, LC, Wisløff, U, and Hoff, J. Aerobic endurance training improves soccer performance. Med Sci Sports Exerc
33: 1925-1931, 2001.
21. Hill-Haas, SV, Coutts, AJ, Rowsell, GJ, and Dawson, BT. Generic versus small-sided game training in soccer. Int J Sports Med
30: 636-642, 2009.
22. Hoff, J, Wisløff, U, Engen, LC, Kemi, OJ, and Helgerud, J. Soccer specific aerobic endurance training. Br J Sports Med
36: 218-221, 2002.
23. Hopkins, WG. Measures of reliability in sports medicine and science. Sports Med
30: 1-15, 2000.
25. Iaia, FM, Rampinini, E, and Bangsbo, J. High-intensity training in football. Int J Sports Physiol Perform
4: 291-306, 2009.
26. Impellizzeri, F, Rampinini, E, and Marcora, S. Physiological assessment of aerobic training in soccer. J Sports Sci
23: 583-592, 2005.
27. Impellizzeri, FM, Marcora, SM, Castagna, C, Reilly, T, Sassi, A, Iaia, FM, and Rampinini, E. Physiological and performance effects of generic versus specific aerobic training in soccer players. Int J Sports Med
27: 483-492, 2006.
28. Impellizzeri, FM, Rampinini, E, Castagna, C, Bishop, D, Ferrari Bravo, D, Tibaudi, A, and Wisløff, U. Validity of a repeated-sprint test for football. Int J Sports Med
29: 899-905, 2008.
29. Krustrup, P, Mohr, M, Amstrup, T, Rysgaard, T, Johansen, J, Steensberg, A, Pedersen, PK, and Bangsbo, J. The Yo-Yo intermittent recovery test: Physiological response, reliability, and validity. Med Sci Sports Exerc
35: 697-705, 2003.
30. Krustrup, P, Mohr, M, Ellingsgaard, H, and Bangsbo, J. Physical demands during an elite female soccer game: Importance of training status. Med Sci Sports Exerc
37: 1242-1248, 2005.
31. MacLeod, H, Morris, J, Nevill, A, and Sunderland, C. The validity of a non-differential global positioning system for assessing player movement patterns in field hockey. J Sports Sci
27: 121-128, 2009.
32. Pate, RR and Kriska, A. Physiological basis of the sex difference in cardiorespiratory endurance. Sports Med
1: 87-98, 1984.
33. Portas, M, Rush, C, Barnes, CC, and Batterham, A. Method comparison of linear distance and velocity measurements with global positioning satellite (GPS) and the timing gate techniques. J Sports Sci Med
6(Suppl. 10): 7, 2007.
34. Rampinini, E, Bishop, D, Marcora, SM, Ferrari Bravo, D, Sassi, R, and Impellizzeri, FM. Validity of simple field tests as indicators of match-related physical performance in top-level professional soccer players. Int J Sports Med
28: 228-235, 2007.
35. Rampinini, E, Impellizzeri, FM, Castagna, C, Abt, G, Chamari, K, Sassi, A, and Marcora, SM. Factors influencing physiological responses to small-sided soccer games. J Sports Sci
25: 659-666, 2007.
36. Ramsbottom, R, Brewer, J, and Williams, C. A progressive shuttle run test to estimate maximal oxygen uptake. Br J Sports Med
22: 141-144, 1988.
37. Randers, MB, Mujika, I, Hewitt, A, Santisteban, J, Bischoff, R, Solano, R, Zubillaga, A, Peltola, E, Krustrup, P, and Mohr, M. Application of four different football match analysis
systems: A comparative study. J Sport Sci
DOI: 10.1080/02640410903428525 (ahead of print). 2010.
38. Reilly, T. An ergonomics model of the soccer training process. J Sports Sci
23: 561-572, 2005.
39. Reilly, T, Bangsbo, J, and Franks, A. Anthropometric and physiological predispositions for elite soccer. J Sports Sci
18: 669-683, 2000.
40. Reilly, T, Williams, AM, Nevill, A, and Franks, A. A multidisciplinary approach to talent identification in soccer. J Sports Sci
18: 695-702, 2000.
41. Stølen, T, Chamari, K, Castagna, C, and Wisløff, U. Physiology of soccer: An update. Sports Med
35: 501-536, 2005.
42. Thomas, JR, Nelson, JK, and Silverman, J. Research Methods in Physical Activity
(5th ed.). Champaign, IL.: Human Kinetics, 2005.
43. Vaeyens, R, Lenoir, M, Williams, AM, and Philippaerts, RM. Talent identification and development programmes in sport: Current models and future directions. Sports Med
38: 703-714, 2008.
44. Vaeyens, R, Malina, RM, Janssens, M, Van Renterghem, B, Bourgois, J, Vrijens, J, and Philippaerts, RM. A multidisciplinary selection model for youth soccer: The Ghent Youth Soccer Project. Br J Sports Med
40: 928-934, 2006.
45. Vincent, WJ. Statistics in Kinesiology
. Champaign, IL: Human Kinetics, 1995.
46. Williford, HN, Scharff-Olson, M, Duey, WJ, Pugh, S, and Barkdale, JM. Physiological status and prediction of cardiovascular fitness in highly trained youth soccer athletes. J Strength Cond Res
13: 10-15, 1999.