Karate competitions are divided into “kata ”(forms) and “kumite ”(match). Kata is characterized by individual and team (three athletes) competitions of standardizes routines, while kumite is a free form of sparring against an opponent. Official karate kumite matches are characterized by 3-minute bouts of high intensity activity involving kicking, punching and quick horizontal displacements (WKF, 2009).
Athletes execute an average of 16.3 ± 5.1 of these decisive actions during the whole match resulting in a total high intensity action time of 19.4 ± 5.5 sec in 3-min matches. Although single kicks and punches are anaerobic alactic and dependent on muscle power, the repetition of these motor actions turns the aerobic pathway the major contributor (77.8% ± 5.8%) to the total energy produced during a kumite match (Beneke et al., 2004). Beneke et al., 2004 also reported that the anaerobic alactic contribution (16.6%) closely represents the time percentage of high intensity actions (16%) during an entire kumite match. However, recovery from these high intensity actions is primary based on aerobic metabolism, and thus explain the large contribution of the aerobic energy pathways for the total energy used.
In addition, anaerobic lactic metabolism can also contribute to the total energy during kumite match. This contribution might be estimated by assessing blood lactate (La) before and after the match. Beneke et al.,2004 showed that La increased 5.9 ± 1.6 mmol·l-1 after a single kumite match (from 1.7 to 7.6 mmol·l-1). Lehmann, 1997 reported similar post kumite match La values. These increases suggest some contribution of the glicolytic metabolism to the total energy expenditure during a kumite match.
Despite the metabolic characteristics of karate, the main criteria to score in kumite matches is the vigorous application of kicks and punches (WKF, 2009). Both actions are performed without external loads and, usually, as fast and powerful as possible. The unique characteristics of the kumite motor actions require a strength assessment that may be able to categorize athletes at distinct competitive levels. For instance, Zehr et al., 1997 observed higher values of loaded (i.e. 10% of their maximal voluntary isometric contraction) and unloaded elbow extension velocity in experienced compared to novice karate players. Further, taekwondo (Toskovic et al., 2004) and judo athletes (Franchini et al., 2005) of different levels show similar 1RM values. Thus, it is possible that karate performance is more dependent on muscle power at low loads than at high loads or on maximal dynamic strength (1RM). Therefore it seems appealing to identify the association of usual power and maximum strength assessments with the kumite performance.
Even though literature presents scattered information regarding strength, power and physiological data (Beneke et al., 2004; Zehr et al., 1997) it is difficult to build a profile of karate players. Moreover, a link between neuromuscular variables and performance results in a competition-like simulation is still lacking. Thus, the aim of this study was to verify the relationship of strength and power with performance on an international level karate team during official kumite match simulations.