Anaerobic Requirements of Elite Judo Athletes
by Wayland Pulkkinen
author of The Sport Science of Elite Judo Athletes
from Hatashita Sports)
This energy system involves both the ATP-CP (Alactic) and Lactate (anaerobic glycolysis) systems. As mentioned previously, judo primarily involves the anaerobic system, therefore training specificity is crucial in the adaptation of this system. The following will be a brief review of the mechanics behind the alactic and lactate energy systems. It will focus on two measures commonly used in sport science to evaluate the effectiveness of training programs, and present a profile of what some world class judo athletes are capable of performing. The judo coach must understand what these components are, and how to adjust training regimes to ensure that the appropriate stimuli are present.
a) Alactic and Lactic Components for Judo Performance
This ability to recover quickly from anaerobic work is essential for competition success, since the total number of matches performed during a tournament may range as high as 6 to 8 bouts (Cipriano, 1993). The alactic system uses creatine phosphate (PCr) to generate intense bursts of action. It is characterized by maximal (100% VO2) exercise lasting 10 to 15 seconds in duration. The value of this system is its tremendous ability to completely replenish stores after depletion within a period of 2 to 3 minutes of rest (Astrand and Rodahl, 1986). In comparison, the lactate system can be defined as anaerobic glycolysis, which is essentially the incomplete breakdown of glycogen in the absence of oxygen (Cipriano, 1993). This occurs during periods of maximal exercise lasting approximately 90 seconds in duration. Lactate is produced and transforms to lactic acid from pyruvate. Lactic acid dissociates into a lactate substrate (Lac-) and hydrogen ions (H+), which causes the muscle pH to decrease (Astrand and Rodahl, 1986). As a result, there is a corresponding increase in muscle acidity, which causes muscle fatigue due to the accumulation of H+. One possible explanation for this fatigue is due to the inhibition of phosphofructokinase (PFK), which is essential for the production of ATP (Astrand and Rodhal, 1986).
In comparison, the lactic energy system can be defined as anaerobic glycolysis, which is essentially the incomplete breakdown of glycogen in the absence of oxygen (Astrand and Rodahl, 1986). This occurs during periods of maximal exercise lasting approximately 90 seconds in duration. This system produces a metabolic bi-product (Lactic acid), which is formed from the transformation from pyruvate to lactate. Lactic acid dissociates into a lactate substrate (Lac-) and hydrogen ions (H+), which causes the muscle pH to drop (Astrand and Rodahl, 1986). This increase in muscle acidity causes a increase in fatigue, due to the accumulation of H+. One explanation for this fatigue is due to the inhibition of the enzyme phosphofructokinase (PFK), which is involved with the production of ATP during anaerobic glycolysis (Astrand and Rodahl, 1986). Removal of lactic acid is fairly slow, and requires approximately 15-20 minutes to remove one half of the concentration of lactic acid formed (NCCP, 1990). Metabolic adaptations to lactate training involve increases in glycolytic enzymes (CPK, PFK, LDH), and increases in buffer capacity (due to increased concentrations of bicarbonate). Also included is hypertrophy, as well as smaller increases in both glycogen and creatine phosphate stores. Long-term changes may involve a conversion from type IIA fibres to type IIB (Astrand and Rodahl, 1986). The application to judo performance essentially involves developing the athlete's corresponding tolerance to muscular fatigue (due to increases in metabolic buffers and larger stores of PrC). In addition to this, the athlete will be able to generate higher power outputs for a longer period of time. Due to the nature of the sport, judoists are required to perform repeated spurts of high intensity activity, which in turn would maximize the use of the lactate system. Results from time motion analysis indicate that judo activity requires a range from 10 to 30 seconds for execution, which is within the time constraints for the lactate system.
Perhaps the most important benefit of aerobic conditioning for judo involves improvements in the lactate threshold. The lactate threshold has been defined as the point at which lactate production exceeds lactate removal (Astrand and Rodahl, 1986). The physical nature of competitive judo requires the athlete to sustain power at a high percentage of their individual VO2 throughout the course of the match. This is obvious when examining the time motion analysis of the judo match and the energy system used in performance. Often, this level of power output would be at or exceed the lactate threshold. Consequently, this would produce high levels of blood lactate, which would in turn promote premature fatigue and ineffective execution of techniques throughout the match. The application to sport performance essentially involves developing the athlete's corresponding tolerance to muscular fatigue. Due to the nature of the sport, judo athletes are required to perform repeated spurts of high intensity activity, which in turn would maximize the use of the lactate system. The adaptations that occur will be a relatively small increase in the concentration of PCr stores within the muscle, although, most of the benefit occurs from an increase in intracellular enzyme concentration. This will assist with a prolonged use of the ATP-CP system as opposed to a pre-mature use of the lactic system. The end result is the athlete's improved ability to perform at a higher percent of his VO2, and thus perform with more intensity and effectiveness in execution of technique.
b) Anaerobic Power and Capacity of Elite Judo Athletes
Some sources have examined the anaerobic power and capacity of elite judo athletes. Evaluations are made by standard Wingate Anaerobic Tests at a set resistance based on the athlete's weight for either legs or arms. Anaerobic capacity is determined by the mean power output throughout a 30 second test. This reflects combined alactic and lactic energy systems. Peak power is determined by the highest power output achieved at any five second period of the test. This is specific to the alactic energy system, and reflects the availability of creatine phosphate stores. Measurements of power are expressed in Watts per kilogram (W.kg), and capacity as Joules per kilogram (J.kg). Resistance for lower body was set at 80 g/kg body mass and upper body at 65 g/kg body mass. Findings by Taylor et al. (1989) revealed that lower body anaerobic peak power and capacity of male Canadian athletes (n=22) were evaluated at a mean of 13.7 W.kg and 320 J.kg respectively. Furthermore, mean values for upper body anaerobic peak power and capacity were determined at 11.3 W.kg and 260 J.kg respectively.
In comparison, Olympic wrestlers have been shown to have peak anaerobic power at 6.1 to 7.5 watts kg-1 (Horswill et al, 1992). Studies by Sharp and Koutedakis (1987) examined anaerobic power and capacity in elite gymnasts, rowers and judo athletes. Resistance was set at 8% of the athlete's body weight. Mean weight values (n=7) for the judoists were 85.0 kg. Upper body mean Wingate values of British judo athletes were found to be 8.5 W.kg for capacity, and 10.6 W.kg for peak power. These values of capacity and peak power were lower than those of gymnasts (9.5 W.kg, 11.0 W.kg) and rowers (10.0 W.kg, 11.5 W.kg) respectively. Sharp and Koutedakis (1987) did conclude that body weight related resistance may constitute a greater proportion of their absolute muscular strength. This may be in part to the wide fluctuation in body mass of the subjects. These sources both emphasize the importance of developing anaerobic power and capacity in judo athletes. Findings by Mickiewicz et al.(1987) are similar when comparing anaerobic capacity of the legs in elite Polish athletes. Mean values for senior and junior males were 11.45 and 11.42 W.kg respectively. Senior female athletes were much lower with a mean value of 9.53 W.kg. Results of Wingate tests on the arms in the junior athletes were found to be a mean value of 8.79 W.kg. Mickiewicz et al (1987) stated that maximum power developed with lower extremities in juniors was higher when compared with power developed in upper extremities. Furthermore, the population examined did not differ in results between senior and junior athletes, thus suggesting that anaerobic capacity may not change with level of judo experience. These values obtained from testing are similar to those of other elite anaerobic based athletes, therefore suggesting some benefit in modifying training regimes. The judo coach must incorporate regular testing of anaerobic power and capacity in order to compare his athlete's scores to other world caliber athletes. If scores are lower than world level competitors, training should focus on improving anaerobic performance until more acceptable values occur.
c) Blood Lactate Concentrations of Judo Athletes in Competition and Training
Measurements of blood lactate can reveal the intensity and degree of training adaptation in athletes, and consequently are an effective means in prescribing exercise intensity for training (MacDougall et al, 1992). Some sources have identified the onset of blood lactate accumulation (OBLA) at 4.0 mmol.L, which is the point at which lactate accumulates in blood exponentially and exceeds the rate of elimination (Astrand and Rodahl, 1986). Some highly anaerobically trained individuals may have lactate accumulation levels that exceed this standard value, therefore, determining individual lactate profiles from a sport specific test is essential in determining optimal training intensity (MacDougall et al, 1992). Taylor et al (1989) found lactate values following lower and upper body Wingate tests to be 15.2 and 14.5 mmol.L, respectively. This was somewhat lower than findings by Mickiewicz et al (1987) following Wingate tests for anaerobic capacity. Results of senior males, junior males and senior females following lower body anaerobic capacity tests demonstrated mean values of 19.3, 15.2 and 15.8 mmol.L respectively. Callister et al (1991) periodically measured lactate values for male and female U.S. athletes throughout 3 months of regular training. Measurements followed sparring matches during free practice (randori), and were determined to have mean values of 8.4 and 7.2 mmol.L, respectively. Randori matches were typically 3 minutes in length, followed by approximately 30 seconds of rest. Callister et al (1991) reported that lactate values following 3 to 7 bouts of randori of this fashion typically measured a mean of 9.1 mmol.L. Blood lactate does not appear to decrease between competition matches, even when adequate rest is provided. In fact, lactate values during competition were found to increase with the number of matches completed. Post-match lactate values of Polish judoists competing in the Matsumae Cup (1986) increased from 10.3, 13.3, 15.9, and 17.2 mmol.L following four matches (Sikorski et al, 1987). In comparison, lactate values of Polish athletes at national championships were found to be a mean of 13.7 mmol.L following 5 matches (Sikorski et al, 1987).
The practical application of testing for blood lactate levels throughout the training year is in establishing adequate baseline levels for training. Most elite judo athletes experience very high levels of blood lactate accumulation during training. In fact, many values exceed 8.0 mmol.L, which is double OBLA levels. High blood lactate levels in combination with hypoxia (low O2 levels) are very effective stimuli for causing the appropriate changes for cellular metabolism. Judo athletes, in particular, would benefit from higher concentrations of oxidative enzymes, thus allowing for higher power outputs. This can directly translate into improved muscle endurance for repeated and sustained muscle contraction needed during a competitive match. In short, the higher the power output, the less fatigue and greater effectiveness of the attack. The judo coach needs to incorporate drills during the training session aimed at improving these parameters. Generally, this type of focus in training would be most beneficial 12 weeks prior to a major competitive event.