Stepwise correlation analysis showed that percent body fat was the best single predictor factor (p < 0.05) of agility (Table 5). Squat 1RM strength was the best single performance predictor for 5- and 10-m sprint times (p < 0.05), whereas 30-m sprint time was best predicted by CMJ performance (p < 0.05).
During the Yo-Yo IR1, players covered 2389 ± 616 m.
This is the first study that has investigated the relationship of squat 1RM with functional tests and the performance determinants of agility in elite male basketball players. The main finding of this study was the existence of significant positive correlations between squat 1RM and sprint times over 5, 10, and 30 m. Surprisingly, agility performance was significantly associated with anthropometric variables such as body mass and percentage of body fat in addition to a negative correlation with the 5JT.
The associations found between squat 1RM and sprint performances (i.e., 10- to 30-m sprint) are in line with that reported by Wisløff et al. (46) in professional male elite soccer players. However, in the present study, significantly lower correlation coefficients were found between squat 1RM and 10-m (r = −0.68 vs. −0.94) and 30-m (r = −0.65 vs. −0.71) performances compared with those reported by Wisløff et al. (46). The difference in correlation coefficient values may be the result of the greater number of subjects used in the study of Wisløff et al. (46) or there may be a sport-specific reason. In this study, no significant difference was observed between 1RM vs. 10-m and 1RM vs. 30-m relationships (−0.68 vs. −0.65, p > 0.80) showing that squat 1RM was equally associated with sprint performances. This means that maximal lower limb dynamic strength is related to a wide range of sprint distances performance in elite basketball. The explained variance (r2) between 1RM and sprint performances suggests that other variables may significantly affect sprinting ability in basketball players.
Agility is reported to be a multifactorial physical ability affected by strength, speed, balance, flexibility, and muscular coordination (37). In this study, agility considered as performance in a basketball-specific test (i.e., T-test) was only significantly related to 5JT performance (r = −0.61). Interestingly, agility performance was also strongly correlated to percent body fat (r = 0.80, p < 0.001) and to a lesser extent to body mass (r = 0.58, p = 0.03). As expected, line-sprinting performances were not related to agility performance. This study's results seem to support the findings of previously investigations in other team sports such as soccer and field hockey (46,49). As a result, agility may be considered as a per se physiological variable probably more dependent on coordinative aspects of performance (37,38). The existing significant relationship with body composition and agility performance, seen in the present study, may be the result of the high intersubject variability existing for the percent body fat (CV = 26.4%). It is possible that the fattest subjects have more difficulty in moving their heavier bodies in the acceleration/deceleration movements imposed by the agility test.
Profiling studies are appearing more frequently in the literature because they provide valuable information on developing normative data and standardized testing for team sports (16).
The anthropometric and physiological characteristics found in the present study were similar to those of previous researches that studied Serbian and French elite-level professional basketball players (32,35). Indeed, Serbian and French elite players showed heights, body masses, and body fat percentages ranging from 196.4 to 199.5 cm, 93.1 to 96.5 kg, and 11.5 to 12.6% respectively (32,35). However, the estimated aerobic capacity of the elite male basketball players in the present study (54.9-59.1 ml·kg-1·min-1) was greater than those reported in the previous 2 studies (32,35). There are several factors that may contribute to this difference, including methodological differences in the testing procedures, the team's style of play, training regimens, and the time of the season when testing occurred. Nevertheless, several authors have argued that the aerobic capacities of elite basketball players are not as important as their anaerobic or physical characteristics and thus a o2max even lower than 55 ml·kg-1·min-1 may be considered as adequate for elite basketball players (26,32,43).
Strength, power, agility, and running speed are thought to be important for successful participation in basketball (32,35). Indeed, Simenz et al. (39) reported in a survey study conducted on NBA professional strength and conditioning coaches that the most popular strength training exercises were Olympic lifts, squats, and plyometric exercises. This type of training is consistent with the literature that addresses the development of strength, power, agility, and running speed (17,20,29,39). Power is heavily dependent on maximal strength, which, when increased, results in improvements in relative strength and therefore in power abilities (46).
There have been no previous studies that have profiled sprint or agility times in elite male basketball players. There are, however, several studies that have profiled sprint and agility times in college male basketball players (19,24,26). The most common distance for assessing sprint capability in college basketball players is 27 m with times ranging from 3.8 to 4.1 seconds being recorded (26). The present study reported sprint times for distance of 5 m (0.82 second), 10 m (1.7 second), and 30 m (4.1 seconds). The only comparison that can be made among these studies is to assess average running velocity over the entire distance. The previous studies reported average running velocities of 6.6-7.1 m·s-1 over 27 m. The present study reported a slightly higher average running velocity of 7.3 m·s-1 over 30 m. It appears that elite basketball players are only slightly faster than their nonelite counterparts over a distance of 27-30 m. However, these comparisons between sprint velocities have to be made with caution because of the 3-m difference in distance. However, because basketball is interspersed with many short sprints (<30 m), further research with elite basketball players is necessary to profile the optimal speed required over these distances (20,21,24,30). From the current and previous researches, it could, however, be speculated that an average running velocity above 7.1 m·s-1 (or below 4.2 seconds) for 30 m would be appropriate for elite male basketball players.
As a result of the physical and physiological similarities in the basketball players used in the present study with those of top international-level basketball players, the results obtained in this study may be regarded as representative of elite-level basketball (32,35).
In light of the present study, findings on agility should be regarded as a major physiological ability in male elite basketball players. Consequently, as a result of the documented specificity of agility training outcome (37,49), basketball-specific drills should be stressed in elite basketball training (i.e., line drills and T-drills). Short sprinting (i.e., 5- to 10-m sprint) should be considered as a basketball-related sprint activity (11,30). Because of the association between squat 1RM performance and short sprint times, squat exercises should be considered in basketball conditioning. As a result of the nature of basketball game, the squat exercises may be used emphasizing the maximal force mobilization during the concentric phase of the squat exercise according to Østerås et al. (31) and Wisløff et al. (47).
However, conclusive inference with regard to the exact impact of squat 1RM performance to basketball-relevant performances may only be drawn after further well-designed training studies. Bench press exercise should not be overemphasized in elite basketball players' training.
This study was supported by the Tunisian Ministry of Scientific Research, Technology and Development of Competences. The authors thank the staff of the National Centre of Medicine and Science in Sports as well as the athletes and the staff of the Tunisian National Basketball team. The authors also thank Dr. Leiper Jhon for revising the English grammar of the manuscript.
1. Atkins, S. Normalizing expressions of strength in elite rugby league players. J Strength Cond Res
18: 53-58, 2004.
2. Baker, D and Nance, S. The relation between running speed and measures of strength and power in professional rugby league players. J Strength Cond Res
13: 230-235, 1999.
3. Bangsbo, J. The physiology of soccer-with special reference to intense intermittent exercise. Acta Physiol Scand
151(Suppl. 619): 1-155, 1994.
4. Bangsbo, J, Iaia, FM, and Krustrup, P. The Yo-To intermittent recovery test: A useful tool for evaluation of physical performance in intermittent sports. Sports Med
38: 37-51, 2008.
5. Berg, K and Latin, RW. Comparison of physical and performance characteristics of NCAA Division I basketball and football players. J Strength Cond Res
9: 22-26, 1995.
6. Bosco, C, Belli, A, Astrua, M, Tihanyi, J, Pozzo, R, Kellis, S, Tsarpela, O, Foti, C, Manno, R, and Tranquilli, C. A dynamometer for evaluation of dynamic muscle work. Eur J Appl Physiol Occup Physiol
70: 379-386, 1995.
7. Bosco, C, Luhtanen, P, and Komi, PV. A simple method for measurement of mechanical power in jumping. Eur J Appl Physiol
50: 273-282, 1983.
8. Buttifant, D, Graham, K, and Cross, K. Agility and speed in soccer players are two different performance parameters. In: Science and Fooball IV
. Spinks, W, Reilly, T, and Murphy, A, eds. London: Routledge, 2002. pp. 329-332.
9. 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.
10. 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.
11. Castagna, C, Vincenzo, M, D'Ottavio, S, Annino, G, Padua, E, and Bishop, D. Relation between maximal aerobic power and the ability to repeat sprints in young basketball players. J Strength Cond Res
21: 1172-1176, 2007.
12. Caterisano, A, Patrick, B, Edenfield, WL, and Batson, MJ. Effects of a basketball season on aerobic and strength parameters among college men: Starters vs reserves. J Strength Cond Res
11: 21-24, 1997.
13. Chamari, K, Chaouachi, A, Hambli, M, Kaouech, F, Wisløff, U, and Castagna, C. The 5-jump test for distance as a field test
to assess lower limbs explosive-power in soccer players. J Strength Cond Res
. 22: 944-950, 2008.
14. Chtara, M, Chaouachi, A, Levin, GT, Chaouachi, M, Chamari, K, Feki, Y, Amri, M, and Laursen, PB. Effect of concurrent endurance and circuit resistance-training sequence on muscular strength and power development. J Strength Cond Res
. 22: 1037-1045, 2008.
15. Durnin, JV and Womersley, J. Body fat assessed from total body density and its estimation from skinfold thickness: Measurements on 481 men and women aged from 16 to 72 years. Br J Nutr
32: 77-97, 1974.
16. Gabbett, T. A comparison of physiological and anthropometric characteristics among playing positions in sub-elite rugby league players. J Sports Sci
24: 1273-1280, 2006.
17. Garhammer, J and Gregor, R. Propulsion forces as a function of intensity for weightlifting and vertical jumping. J Appl Sport Sci Res
6: 129-134, 1992.
18. Gilliam, G. Identification of anthropometric and physiological characteristics relative to participation in college basketball. NSCA J
7: 34-36, 1985.
19. Hoffman, J, Fry, AC, Howard, R, Maresh, CM, and Kraemer, WJ. Strength, speed and endurance changes during the course of a Division I basketball season. J Strength Cond Res
5: 144-149, 1991.
20. Hoffman, JR, Cooper, J, Wendell, M, and Kang, J. Comparison of Olympic vs traditional power lifting training programs in football players. J Strength Cond Res
18: 129-135, 2004.
21. Hoffman, JR, Epstein, S, Einbinder, M, and Weinstein, Y. The influence of aerobic capacity on anaerobic performance and recovery indices in basketball players. J Strength Cond Res
13: 407-411, 1999.
22. Hoffman, JR, Epstein, S, Einbinder, M, and Weinstein, Y. A comparison between the Wingate anaerobic power test to both vertical jump
and line drill tests in basketball players. J Strength Cond Res
14: 261-264, 2000.
23. Hoffman, JR and Maresh, CM. Physiology of basketball. In: Exercise: Basic and Applied Science
. Garrett, WE, and Kirkendall, DT, eds. Baltimore: Lippincott Williams & Wilkins, 2000. pp. 733-744.
24. Hoffman, JR, Tenenbaum, G, Maresh, CM, and Kreamer, WJ. Relationship between athletic performance tests and playing time in elite college basketball players. J Strength Cond Res
10: 67-71, 1996.
25. 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.
26. Latin, RW, Berg, K, and Baechle, T. Physical and performance characteristics of NCAA Division I male basketball players. J Strength Cond Res
8: 214-218, 1994.
27. Little, T and Williams, AG. Specificity of acceleration, maximum speed, and agility in professional soccer players. J Strength Cond Res
19: 76-78, 2005.
28. Matavulj, D, Kukolj, M, Ugarkovic, D, Tihanyi, J, and Jaric, S. Effects of plyometric training on jumping performance in junior basketball players. J Sports Med Phys Fitness
41: 159-164, 2001.
29. McBride, JM, Triplett-McBride, T, Davie, A, and Newton, RU. A comparison of strength and power characteristics between power lifters, Olympic lifters and sprinters. J Strength Cond Res
13: 58-66, 1999.
30. McInnes, SE, Carlson, JS, Jones, CJ, and McKenna, MJ. The physiological load imposed upon basketball players during competition. J Sports Sci
13: 387-397, 1995.
31. Østerås, H, Helgerud, J, and Hoff J. Maximal strength-training effects on force-velocity and force-power relationships explain increases in aerobic performance in humans. Eur J Appl Physiol
88: 255-263, 2002.
32. Ostojic, SM, Mazic, S, and Dikic, N. Profiling in basketball: Physical and physiological characteristics of elite players. J Strength Cond Res
20: 740-744, 2006.
33. Paavolainen, L, Hakkinen, K, Hamalainen, I, Nummela, A, and Rusko, H. Explosive-strength training improves 5-km running time by improving running economy and muscle power. J Appl Physiol
86: 1527-1533, 1999.
34. Pauloe, K, Madole, K, Garhammer, J, Lacourse, M, and Rozenek, R. Reliability and validity of the T-test as a measure of agility, leg power, and leg speed in college-aged men and women. J Strength Cond Res
14: 443-450, 2000.
35. Sallet, P, Perrier, D, Ferret, JM, Vitelli, V, and Baverel, G. Physiological differences in professional basketball players as a function of playing position and level of play. J Sports Med Phys Fitness
45: 291-294, 2005.
36. Semenick, D. The T-test. NSCA J
12: 36-37, 1990.
37. Sheppard, JM and Young WB. Agility literature review: Classifications, training and testing. J Sports Sci
24: 919-932, 2006.
38. Sheppard, JM, Young, WB, Doyle, TL, Sheppard, TA, and Newton, RU. An evaluation of a new test of reactive agility and its relationship to sprint speed and change of direction speed. J Sci Med Sport
9: 342-349, 2006.
39. Simenz, CJ, Dugan, CA, and Ebben, WP. Strength and conditioning practices of National Basketball Association strength and conditioning coaches. J Strength Cond Res
19: 495-504, 2005.
40. Slattery, KM, Wallace, LK, Murphy, AJ, and Coutts, AJ. Physiological determinants of three-kilometer running performance in experienced triathletes. J Strength Cond Res
20: 47-52, 2006.
41. Spinks, CD, Murphy, AJ, Spinks, WL, and Lockie, RG. The effects of resisted sprint training on acceleration performance and kinematics in soccer, rugby union, and Australian football players. J Strength Cond Res
21: 77-85, 2007.
42. Stapff, A. Protocols for the physiological assessment of basketball players. In: Physiological Tests for Elite Athletes
. Gore, CJ ed. Champaign, IL: Human Kinetics, 2000. pp. 1-27.
43. Tavino, LP, Bowers, CJ, and Archer, CB. Effects of basketball on aerobic capacity, anaerobic capacity, and body composition of male college players. J Strength Cond Res
9: 75-77, 1995.
44. Thomas, JR, Nelson, JK, and Silverman, J. Research Methods in Physical Activity
(5th ed.). Champaign, IL: Human Kinetics, 2005.
45. Weiss, LW, Wood, LE, Fry, AC, Kreider, RB, Relyea, GE, Bullen, DB, and Grindstaff, PD. Strength/power augmentation subsequent to short-term training abstinence. J Strength Cond Res
18: 765-770, 2004.
46. Wisløff, U, Castagna, C, Helgerud, J, Jones, R, and Hoff, J. Maximal squat strength is strongly correlated to sprint-performance and vertical jump
height in elite soccer players. Br J Sports Med
38: 285-288, 2004.
47. Wisløff, U, Helgerud, J, and Hoff, J. Strength and endurance of elite soccer players. Med Sci Sports Exerc
30: 462-467, 1998.
48. Young, WB, Benton, D, Duthie, G, and Pryor, J. Resistance training for short sprints and maximum-speed sprints. Strength Cond J
23: 7-13, 2001.
49. Young, WB, McDowell, MH, and Scarlett, BJ. Specificity of sprint and agility training methods. J Strength Cond Res
15: 315-319, 2001.