Football-specific fitness testing: adding value or confirming the evidence?
This cheeky commentary, written 5 years ago with my brilliant friend Alberto Mendez-Villanueva is still 200%up to date, and deserved to be brought back to the scene. Enjoy!
In the search for the ultimate competitive edge, in the last years, professional football (soccer) clubs have substantially increased their budget allocation for sport science personnel and support. Among others, the assessment of players’ physical fitness is a major part of the sport science service. Physical fitness testing is typically conducted several times per year to evaluate different physical qualities (e.g., aerobic fitness, speed, agility, and strength and power), which are to some degree thought to be related to match play physical performance. In the recent years, an increasing number of so-called “football-specific fitness tests” have been gaining momentum and their use in professional football has rapidly widespread. Typically, such football-specific fitness tests are generally deemed “specific” as long as they can show some sort of logical, construct and/or other forms of validity (Impellizzeri & Marcora, 2009). Football-specific tests of speed (Rampinini, et al., 2007), aerobic function (Bangsbo, Iaia, & Krustrup, 2008), agility (Bullock, Panchuk, Broatch, Christian, & Stepto, 2012; Sporis, Jukic, Milanovic, & Vucetic, 2010) and dribbling ability (Huijgen, Elferink-Gemser, Post, & Visscher, 2009) have been “validated” and are now implemented in many football clubs and academies worldwide. Despite their proposed scientific robustness, perceived practicality and the increasing popularity, whether these football-specific fitness tests can really bring new information to the team and individual players can still be questioned.
As most sprints during a football game have been shown to happen over distances inferior to 10 meters (Di Salvo, et al., 2010), 5- to 10-m sprints are considered as extremely football-specific speed tests. That is, there is no doubt that a 5-m sprint test has good logical validity. As such, 5-m sprint times are considered as highly relevant and useful for the coaching staff and players. However, while it is nice to put an actual “number” on a player’s acceleration capacity (i.e., 5-m sprint test), does this assessment really translates into new and meaningful information for the coaching staff and players? First, with respect to the assessment of a players’ locomotor profile, reality is that, in most cases, coaches already know who the fast players are. Thus, in most cases, a 5-m sprint test could just confirm something that was already evident for the coaching staff. Accordingly, knowledge of a player’s 5-m sprint time is actually unlikely to change how coaches perceive his/her potential and playing skills. In contrast to other sports (e.g., track and field), a lack of speed (or any other fitness quality) in football has always to be put first in relation to playing roles and tactical demands. We believe that as long as a player is able to do his/her “job” satisfactorily on the field, all other (physical) considerations are secondary (Delgado-Bordonau & Mendez-Villanueva, 2012). Along these lines of thinking, the real problem for a player is not to be slow per se, but not to be a good football player because of a lack of speed or acceleration. In this latter case, an understanding of the causes/factors responsible for the poor 5-m sprint time and, in turn, diminished potential football ability, would be highly valuable to the coaches and players, e.g., to potentially built up an individual training intervention. Finally, since in reality, a football-specific speed test (i.e., 5-m) might not be that informative to coaches, scientists and players, the potential interest of other running speed parameters might need to be considered. We believe that, in addition to the 5-m sprint times, the assessment of maximal sprinting speed (MSS) (Buchheit, Simpson, Peltola, & Mendez-Villanueva, 2012) has clear applications and might reveal ‘hidden’ information to the coaching staff. While this running speed is unlikely reached during games (Mendez-Villanueva, Buchheit, Simpson, Peltola, & Bourdon, 2011), it directly determines the relative neuromuscular load/strain that players encounter during games and training session (Mendez-Villanueva, Buchheit, Simpson, & Bourdon, In press). This kind of information can be highly valuable when programing individual training plans and exercise intensities, monitoring training/competitive load and for the management of injured players.
The present discussion can also be extended to the aerobic fitness assessment throughout football-specific, intermittent field tests, such as the Yo-Yo tests (Bangsbo, et al., 2008).The outcome measure of these tests (i.e., total distance covered) has been shown to be related, among others, to factors such as maximal oxygen uptake (Bangsbo, et al., 2008), metabolic control (Rampinini, et al., 2010), acid-base status (Rampinini, et al., 2010), explosive leg power (Castagna, Impellizzeri, Chamari, Carlomagno, & Rampinini, 2006) and potentially to acceleration capacity and the ability to change direction. That is, Yo-Yo performance is a compound quality which depends on a myriad of physical fitness factors. As such, a given Yo-Yo performance can be achieved while taxing the above-mentioned physiological determinants at a fairly different extend (e.g., a player might compensate his poor aerobic power by a great anaerobic capacity to reach a similar Yo-Yo performance than a player with an opposite physiological profile). In practice, with a Yo-Yo performance, what kind of specific training recommendations can be given to the player and coaching staff? Concluding that due to a poor Yo-Yo test result, a player has to improve his/her ability to repeat high-intensity exercise is actually very simplistic and not informative at all. Analogous, this is similar to say that a slow player has to improve his ability to run faster. In addition, high-intensity intermittent exercise performance has also to be seen in relation to its possible impact 1) on match running performance, which is likely position-dependent (Buchheit, Mendez-Villanueva, Simpson, & Bourdon, 2010), and more importantly, 2) match play technical/tactical performance. Similar to the above example on the 5-m sprint time, most likely coaches would already know if a player has or not the ability to perform (and repeat) high-intensity actions, and whether this is actually problematic or not for his technical/tactical game performance. Again, such a fitness assessment only confirms what was likely already evident to most coaches. If poor playing performance was actually to be linked to a poor ability to repeated high-intensity exercise, how a test that quantifies something which is already evident could help in identifying the actual problem?
Another obvious limitation of these kind of tests, is that their final performance do not represent a clear locomotor entity (Dupont, et al., 2010), so that they cannot be used for training prescription. We therefore adhere to the assessment of a combination of isolated physical capacities, including, among others, maximal aerobic speed (MAS). While its assessment is everything but specific (it involves continuous running without changes of direction), MAS is the only field-based measure that reflect a player’s maximal aerobic power, integrated with his/her running economy (di Prampero, Atchou, Bruckner, & Moia, 1986). In practice, MAS can be used as a reference for programming high-intensity training (Dupont, Akakpo, & Berthoin, 2004), and when it is put in relation to either Yo-Yo or match running performance, the relative physical strain of such exercises can be estimated.
To conclude, while appealing, excessive reliance on football-specific fitness tests can easily end up with sport scientists playing a limited role of “evidence providers”, rather than substantially impacting players and teams’ performances. We believe that football sport scientists working in professional settings should not (only) test to confirm evidences, but also try to implement testing batteries aimed at improving the profiling of players’ physical and physiological capacity, which is, in turn, is more likely to impact soccer-specific movement patterns and ultimately, competitive performance.
Full reference: Mendez-Villanueva A. and Buchheit M. Football-specific fitness testing: adding value or confirming the evidence? Journal of Sports Sciences, 2013;31(13):1503-8.
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