As covid-19 lockdown measures begin to ease, and judo clubs are making the gradual return to full training, I thought it a good time to consider some of the demands of contest judo, and what judoka (those who compete) are preparing for.
As mentioned in a previous post, during 2009 and 2010 I contributed to three publications on the topic of strength and conditioning for judo. Whether it is for judo, or other sports, effective strength and conditioning programmes should aim to improve performance, and reduce the risk of injury. To achieve these aims, strength and conditioning programmes should specifically address the demands of the sport, as established using a needs analysis. Once the demands have been established, suitable training activities can then be programmed to prepare the athlete for the demands that will be placed upon them.
One factor that influences the demands of a sport, are the competition or contest rules. Since my co-author and I produced our work on strength and conditioning for judo, there have been some changes in judo contest rules (e.g., removal of leg grabs in tachi-waza, reduction of contest time for males), and re-interpretations of aspects such as time allowed holding an unorthodox grip in tachi-waza. Consequently, it is possible that such changes and re-interpretations may have had an effect on the demands judo contests place on judoka.
In 2009 my co-author and I concluded that competing in a judo contest…
“…is primarily a high-intensity, intermittent anaerobic activity…”
(Robertson and Lahart, 2009)
This conclusion was based upon the work-to-rest ratios (3: 1), high heart rates (> 90% maximum heart rate), and high blood lactate levels (~ 10 mmol/L-1) reported for judo contests in the literature we reviewed. Additionally, the literature suggested that the ability to produce repeated bouts of high-intensity work characterised judoka who competed at higher levels; whilst aerobic capacity (as measured by VO2 max) did not distinguish between levels of judoka, with moderate (~ 48 ml-1∙kg-1∙min-1) to high (~ 70 ml-1∙kg-1∙min-1) levels reported in elite judoka.
That judoka can compete at a high-level with moderate aerobic capacity could be taken to indicate that aerobic capacity is perhaps not a priority for training, particularly as decisive actions (e.g., throws) rely predominantly upon anaerobic energy production. However, it is possible, as we noted, that technical and tactical superiority might compensate for any deficiencies in aerobic capacity. Moreover, regardless of technical and tactical superiority…
“…high levels of aerobic capacity may help to maintain power output when anaerobic energy production decreases [towards the end of a contest].”
(Lahart and Robertson, 2009)
Aerobic capacity should also be considered important due to the aerobic energy system’s role in recovery between bouts of high intensity work, both within and between contests.
Research published in 2017 attempted to quantify energy system contributions during judo contests, and further highlighted the importance of the aerobic energy system. The research identified that the aerobic system contributed the majority of energy (compared to each of the two anaerobic systems) during simulated judo contests, with this contribution increasing as contests progressed. Such findings help to emphasise the need for judoka to undertake appropriate aerobic training, and highlight that summaries of contest judo should account for the aerobic demands. Yet, it should be noted that the findings from this 2017 research are from 5 minute contests (not 4 minute contests as per the current rules), and that the contests did not incorporate all aspects of a contest (in order to protect the measurement equipment used).
Other research published since our work has identified (as we did) a contest work-to-rest ratio of ~ 3: 1, although this may range between from 3: 1 to 2: 1 throughout a contest. However, as with the energy system contribution research, this research was not carried out under the current rules. Consequently, as stated in the 2018 book The Science of Judo, there is a need for research to be carried out using the current rules to establish the present demands of judo contests. However, as we approach the end of the current Olympic cycle, there is a possibility that the rules may be amended or reinterpreted for the next cycle, therefore potentially affecting the demands of contest judo.
In summary, the amount of research into the demands of contest judo since our work in 2009 and 2010 has increased, with only a small proportion of it cited in this post. Despite being based on simulated contests, the energy system contribution research cited emphasises the need to ensure that the aerobic system is developed, and highlights that our original conclusion did not sufficiently identify the importance of aerobic energy production during contests. Work-to-rest ratios appear similar, but we do not yet know the effect of the current rules on this aspect of contest judo. There is also the potential for future rule changes that may affect the contest work-to-rest ratio.
Whilst research into the demands of contest judo has its challenges (e.g., having to use simulated contests, keeping up with rule changes), it does provide some basis for strength and conditioning programme design. As coaches, when designing programmes, we should aim for specificity by using the information available to us (treating it with caution where necessary), and integrating it with our previous experience of developing athletes. Moreover, we should remain aware that specificity when preparing athletes does not always mean exact replication or simulation of competition.
Paul Robertson, PhD 