Biomechanics Laboratory, Federal University of Santa Catarina, Florianópolis, Brazil.
Physiological capacities are continuously developed throughout childhood and adolescence, mainly due to the growth and maturation development1. For example, strength and power capabilities begin to emerge in prepubescent children through increases in muscle mass2. Both aerobic and anaerobic systems are progressively enhanced over the childhood and adolescence, but the aerobic system is developed earlier due to the growth of circulatory, respiratory and muscular systems3. Thus, it is important for the coach to monitor constantly the physical capacities of young athletes in order to provide more adequate and individual training loads. In this sense, some specific assessments have been proposed to monitor physical capacities in judo athletes. As indicators of judo-specific performance, the Special Judo Fitness Test (SJFT) and Judogi Grip Strength Test (JGST) (Figure 1) may be highlighted. The SJFT has become the most commonly used tool to indirectly estimated anaerobic and aerobic capacities4 and JGST to estimate the strength-endurance in the upper body5.
This text presents two investigations with young judo athletes, in which show the predictors of judo-specific performance, and the role of maturation, growth and judo experience on the specific performance.
Figure 1. Illustration of Judogi Grip Strength Test (A = back view; B = side view, more information see Franchini et al.5) and Special Judo Fitness Test (C) (more information see Franchini et al.4 and https://www.youtube.com/watch?v=jUssMcYYQ60).
First, ninety-four children and adolescents from Brazil (66 boys and 28 girls, age range 11-16 years) were analyzed6. We verified that the SJFT was strongly correlated with the standing long jump test (Figure 2A) and medicine ball throw test (Figure 2B) in both boys and girls. These findings point out that a good performance in SJFT depends on high levels of muscle power in lower and upper limbs. Moreover, handgrip strength test (Figure 2C) was correlated to SJFT only for boys, indicating that maximal isometric handgrip strength is also an important contributor to SJFT performance, especially in boys. Finally, high levels of muscle power of upper limbs and handgrip strength are determinant for JGST performance mainly in boys.
Figure 2. Illustration of Standing Long Jump Test (A), Medicine Ball Throw Test (B) and Handgrip Strength Test (C).
Second, another important question for coaches is the role of maturation, growth and training experience on judo-specific performance (e.g. SJFT and JGST). It was observed that the maturation (estimated by age at peak velocity), judo experience (training) and body fat were significant predictors of SJFT performance7 (Table 1). These findings emphasize that adolescent judo athletes who were leaner, later maturing and more experienced achieved better performance in SJFT. The later maturing boys possibly more efficiently utilize aerobic energy sources and demonstrate a lower dependence of anaerobic metabolism than their earlier maturing counterparts8. Considering JGST, the results showed that older, shorter, lighter, leaner and earlier maturing boys tend to exhibit high performance in this test.
Table 1. Predictors of judo-specific tests performance and the respective indicator in youth male judo athletes.
- Strength and power capabilities of upper and lower limbs are related to judo-specific tasks performance (SJFT and JGST) in young athletes;
- The maturation, growth and judo experience are important predictors of performance in SJFT and JGST;
- It is recommended to maintain lower levels of body fat in young judo athletes, as it is a negative predictor of performance as well as harmful to health;
- Coaches may use simple and accessible assessments (e.g. standing long jump, medicine ball throw and handgrip strength tests) to monitor physical performance and control the training effects in young judo athletes;
- The SJFT and JGST are good alternatives to access specific performance in judo athletes, especially considering the complexity of obtaining a single marker of performance during judo matches.
- Malina, R. M., Bouchard, C., & Bar-Or, O. (2004). Growth, maturation, and physical activity. Champaign, IL: Human Kinetics.
- Lloyd, R. S., & Oliver, J. L. (2012). The youth physical development model: A new approach to long-term athletic development. Strength & Conditioning Journal, 34, 61-72.
- Engel, F. A., Ackermann, A., Chtourou, H., & Sperlich, B. (2018). High-intensity interval training performed by young athletes: a systematic review and meta-analysis. Frontiers in Physiology, 9, 1012.
- Franchini, E., Del Vecchio, F.B., Sterkowickz, S.A. (2009). Special Judo Fitness Test classificatory table. Archives of Budo, 5, 127-129.
- Franchini, E., Miarka, B., Matheus, L., & Del Vecchio, F. B. (2011). Endurance in judogi grip strength tests: Comparison between elite and non-elite judo players. Archives of Budo, 7, 1-4.
- Kons, R. L., da Silva Athayde, M. S., da Silva Junior, J. N., Katcipis, L. F. G., & Detanico, D. (2020). Predictors of judo-specific tasks from neuromuscular performance in young athletes aged 11–16 years. International Journal of Sports Physical Therapy, 15, 365-373. Available in: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7297007/
- Detanico, D., Kons, R. L., Fukuda, D. H., & Teixeira, A. S. (2020). Physical Performance in Young Judo Athletes: Influence of Somatic Maturation, Growth and Training Experience. Research Quarterly for Exercise and Sport, ahead of print. Available in: https://pubmed.ncbi.nlm.nih.gov/31906807/
- Doncaster, G., Iga, J., & Unnithan, V. (2018). Assessing differences in cardiorespiratory fitness with respect to maturity status in highly trained youth soccer players. Pediatric Exercise Science, 30, 216–228.