Handgrip strength is a general term used in clinical (29,47,56) and occupational (17,33,44,60) settings and by strength athletes (9,38). It refers to the muscular strength and force that can be generated by the hands. The strength of a handgrip is the result of the maximum force that the subject is able to exert under normal biokinetic conditions through the voluntary flexion of all finger joints, thumbs, and wrists (37). Factors that are considered during these activities include the absolute level of strength necessary to perform the tasks and the fatigue experienced by the muscles responsible for these movements (4).
Several sporting activities require the maintenance of adequate levels of handgrip strength to maximize control and task performance and decrease injury risk (4). Judo is a sport in which handgrip strength is essential. During the bout, a judo athlete grips the opponent's uniform (judogi), which provides the basis for the execution of the throwing techniques (nage-waza) (2). This results in a high physiological demand on the upper body (6,24,46). Although the fight situation in judo is quite complex and the outcome is defined by >1 variable (22), the gripping method (kumi-kata) is the first contact between 2 judo athletes and may determine the result of the bout (16,26,40).
Given its importance, the isometric handgrip peak strength in different groups of judo athletes is well documented in the literature (14,18,21,22,40,43). After reviewing research published to date, Franchini et al. (23) concluded that high-level male and female judoka differ less between themselves with respect to isometric handgrip strength than do less competitive level judo athletes, particularly when the data are expressed relative to body weight. These authors also note the absence of significant differences in the levels of isometric handgrip strength of high-level judo athletes in their 60s (43).
On the other hand, the evaluation protocol used in these investigations (a single maximal isometric contraction of between 5- and 10-second duration) does not correspond to the reality of combat. In a combat situation, judo athletes repeat this action at least 15 or 20 times per bout (27,54) for a median time of almost 8 minutes that a combat can last. It therefore consumes 51 ± 11% of the time during the struggle for grip (42). This typical time structure of a judo bout, with between 15 and 30 seconds of activity alternating with between 5 and 10 seconds of interval periods (13,49,58), is characterized by the important participation of anaerobic metabolism that produces lactic acid. Lactic acid concentrations found after bouts between experienced judo athletes range from 13 to 18 mmol·L−1 (11,12,25,28,46,48,50,57). This intensity is confirmed by mean heart rates during bouts in simulated contests recorded at between 180 and 185 b·min−1, which correspond to effort intensities above the respiratory compensation point for metabolic acidosis (VT2) (6,7,11,46). The negative effects of high hydrogen ion (H+) concentrations on sporting muscular performance have been well documented (1,5,31,34,36,61,63). However, depending on the intensity of the isometric contraction, it has been observed that changes in lactic acid production are 2–3 times greater at 25–60% than at 90–95% of maximal isometric force (45). Acidosis could therefore be considered to be one of the main causes of loss of grip strength at these intensities (10,34,53). In addition, it has been observed that the performance of an intermittent gripping task, such as that during judo combat, increases the endurance time and reduces the recovery time relative to a continuous exercise (51).
These observations therefore highlight the importance of endurance of the isometric handgrip strength as a major determining factor of success in judo (23). In line with this, some authors claim that the isometric peak grip strength value for the hand during a judo bout is less important for a successful grip than the endurance because of the loss of grip strength, because the athletes perform a near continuous grip during a judo bout and the maximal strength is not maintained for a long period (8,23). Yet few studies to date have analyzed the isometric grip strength endurance in judo athletes. Bonitch-Góngora et al. (8) found losses of 39% of maximum isometric hand grip strength in national-level judo athletes during a test interval of 10 repetitions of 10 seconds alternated by 10 seconds of recovery. Only one investigation (32) has analyzed the effect of the fighting on the maximal isometric handgrip strength (2 judo bouts of 5 minute duration with 15 minutes of passive recovery between each). This study found that maximal isometric handgrip strength decreases for both hands by >5% in the first postbout and by 15% in the second postbout.
These studies demonstrate the fatigability of the gripping muscles of the forearms of judo athletes. However, more research is needed to better understand the behavior of the maximum isometric handgrip strength and to analyze in depth the causes of their decline in real combat situations, because high-level judo athletes can participate in between 5 and 7 fights on the same day to get a place among the top 5 competitors (25). The key aim of this study is therefore to analyze changes to the maximal isometric handgrip strength in the hands because of a bout, or series of bouts, and its relationship with the observed lactic acid levels.
Experimental Approach to the Problem
This study followed a repeated measures intragroup protocol whereby each subject participated in a simulated judo contest consisting of 4 bouts (4 levels of the independent variable) separated by a passive recovery period. The bout and recovery times were established beforehand. The resulting maximal isometric strength of both hands, prebout and postbouts, was measured, and blood samples were taken during the recovery period to determine the maximal lactate concentration and lactate clearance between bouts.
Twelve male judo-athlete volunteers from different weight categories were recruited (Table 1). Ten of the athletes were, or had been, medalists in national championships in Spain and France in different age categories; the remaining 2 had won medals in regional competitions in Andalusia (Spain). All the subjects had been practicing judo for >10 years, training for between 12 and 18 h·wk−1, and had technical levels ranging from first to third Dan. Informed consent was obtained from each participant according to the Institutional Review Board of the University of Granada, and the evaluation protocol was approved.
All of the subjects were tested during the competitive period. During this period, the subjects were training in judo specific tasks (6–8 judo sessions per week, 2 hours per session) and were strength training (1–3 times per week) to develop the power of different muscle groups.
The subjects performed a training session with the grip test to familiarize themselves with the instrumentation and the maximal isometric handgrip strength measurement protocol, for which we used a digital dynamometer (Psymtéc TKK-5101, Madrid, Spain). As recommended by Watanabe et al. (60), the subjects made various attempts with both hands, noting the most comfortable distance to the handle when gripping the dynamometer, and this distance was maintained during all subsequent tests. Each subject was instructed to maintain maximal isometric contraction during each measurement for between 3 and 6 seconds (15,41). Contractions were made with each hand with both feet on the floor, the shoulder bent by 90°, and the elbow completely extended (Figure 1).
Each subject participated in a simulated judo contest. This contest consisted of four 5-minute bouts (actual combat time) separated by 15 minutes of passive recovery (6,15,20,25). Each bout took place on a regulation tatami judo mat installed in the School of Exercise and Sports Science of the University of Granada and was controlled by referees and timekeepers from the Andalusian Judo Federation and Associated Disciplines. To ensure that all the bouts in this study lasted for the officially allotted time, the official regulation that specifies “a contest will end when one contestant has achieved ippon or equivalent” (article 19 of the International Judo Federation's Referee Rules) was modified. This resulted in victory being decided only at the end of the bout by totaling all the points scored (yuko = 5 points, waza-ari = 7 points, ippon = 10 points and the summation of shido with its equivalence to yuko, waza-ari, or ippon).
All the contests were performed in the morning (10:00–14:00), and the temperature of the room ranged from 16 to 20°C.
To generate a demanding competitive environment, the subjects were divided into pairs of the same weight (difference of <10%) and similar ranking as published by the Andalusian Judo Federation and Associated Disciplines (25) and were paid for each victory achieved.
The testing apparatus was set up, in duplicate, at a distance of 4 m from the tatami's safety zone. The judo athlete performed the manual dynamometry test in the 30 seconds immediately before (pre) and after (post) each bout according to the instructions provided in the familiarization session. The test was first performed with the dominant hand and then with the nondominant one. A single measurement was taken for each hand to obtain the maximal isometric handgrip strength values of prebouts and postbouts.
A 10-μL blood sample was taken from the fingertip at 1, 3, and 14 minutes after each bout, and the lactic acid concentration was determined using a photoenzymatic apparatus (Dr. Lange, LP 20 plus) (19). The highest lactic acid concentration reached between bouts was taken as the maximal value. The percentage of lactic acid clearance between bouts was determined from the difference between Lacmax and Lac14.
This protocol more closely reproduced judo combat activity (e.g., temporal structure) and therefore physiological responses (e.g., blood lactate concentration) as described in the literature (7,25,48). To ensure that the temporal structure of the contests was as close as possible to competition conditions, the entire experimental phase was recorded with a Sony DCR-TRV14OE digital camera. The mean effort and rest periods, and the number of attacks, were calculated for each bout. The reliability of this method has been established previously (13,15,28).
All results are quoted as mean ± SD. The Shapiro-Wilk test was used to analyze the frequency distribution. The overall effect of the independent variable on the measurements taken before and after each bout was determined by analysis of variance (ANOVA) using repeat measures with bout number (1, 2, 3, or 4) as an intrasubject factor. A variance analysis was performed by applying a Greenhouse-Geisser or Huynh-Feldt correction if the Mauchly sphericity test was significant. In the event of a significant ANOVA, the Sidac test was applied for between-pair comparisons. Variables with a nonnormal distribution were analyzed using the Friedman and Wilcoxon test (α < 0.05/4). The comparisons between measurements of prebouts and postbouts were achieved by performing a Student-t or Wilcoxon test for paired data. We used a Pearson or Spearman correlation analysis to analyze the intervariable relationships. A confidence interval of 95% was established in all cases.
The mean times for the rest and effort phases during the bouts were 13.79 ± 9.47 and 13.95 ± 9.09 seconds, respectively, and the mean number of attacks during each bout was 10.5 ± 4.1.
The judo athletes tested had a mean maximal isometric handgrip strength of 0.78 ± 0.08 and 0.75 ± 0.11 kg·kg−1 when gripping with the dominant and nondominant hands, respectively.
The maximal isometric strength values for each hand for prebouts and postbouts are listed in Table 2. An overall effect of the successive bouts on the maximal isometric strength of prebouts was observed for both hands (p = 0.002 and p = 0.000 for the dominant and nondominant hands, respectively). The pair comparison showed a significant decrease in the maximal isometric handgrip strength of the third and fourth prebouts with respect to that found in the first prebout for both hands (p < 0.05). The maximal isometric strength recorded at the third and fourth prebouts was significantly higher for the dominant hand than for the nondominant hand. There were no significant changes in the maximal isometric strength of postbouts, and similar values were found for both hands (Table 2).
A comparative analysis of the maximal isometric strength values of prebouts and postbouts for both hands is shown in Figure 2. The dominant hand shows an overall decrease in maximal isometric handgrip strength because of the combat, with this decrease being significant for the first, third, and fourth bouts (p < 0.05). The nondominant hand shows a significant decrease in its maximal isometric handgrip strength only at the first prebouts and postbouts (p < 0.05), with no major changes during the rest of the contest.
The blood lactic acid concentrations during the recovery periods are shown in Table 3. A significant effect of successive combats on the Lacmax and the Lac14 (p < 0.01) can be seen. The pair-comparison analysis shows a significant drop in both values of the fourth bout compared with those of the first and second bouts (p < 0.05). The clearance follows a similar trend for all 4 bouts (p > 0.05).
Results of the correlation analysis are shown in Table 4, in which inverse relationships between maximal isometric handgrip strength, and the Lacmax and Lac14, are seen in all cases. The correlation between maximal isometric handgrip strength of postbouts and the Lacmax is significant for the second and fourth bouts (p < 0.05), and the correlation between maximal isometric handgrip strength of postbouts and Lac14 is significant for all 4 bouts (p < 0.05). From the second bout onward, there is also a strong relationship between Lac14 and the maximal isometric handgrip strength of the following prebout (p > 0.05). This relationship is most stable for the dominant hand in all cases.
In this study on national-level judo athletes, it initially seemed plausible that high levels of peak force in a maximal isometric contraction in the hand grip could be developed by the athletes, because grip strength is vital to the development of attack and defense techniques in judo (18,22,26,40). The maximal isometric handgrip strength values observed in our study sample (575.85 ± 69.14 and 554.26 ± 74.20 N for the dominant and nondominant hands, respectively, in the first prebout) are similar to those found in other studies of judo athletes at similar competitive levels (18,40,55).
This study, however, demonstrates an effect of the bout on the maximal isometric handgrip strength (prebout vs. postbout) for both hands, with the progression of the tournament and the succession of bouts. It showed a decrease in starting maximal isometric handgrip strength for each bout. In addition, it demonstrated a lack of complete recovery between bouts that was greater for the nondominant than for the dominant hand, thus showing that each hand works in a different manner. The limit of maximal isometric handgrip strength loss appears to be stable throughout the contest as a whole and is related to the posteffort lactic acid concentration, particularly in the dominant hand. This shows that the judo athletes are unable to recover their initial levels of grip strength throughout the course of the tournament and, for the first time, suggests that fatigue of each hand depends on different factors.
According to Walker et al. (59), the percentage loss of grip strength during each bout could be related to the corresponding initial maximal isometric strength. For example, these authors reported that during prolonged isometric contraction, 50% of a higher maximal isometric strength was more effective in terms of resistance capacity than 50% of a lower initial maximal isometric strength. This suggests that, as indicated by our results, as the bouts progress and fatigue begins to accumulate, the drop in initial maximal isometric strength (<91.80% in the dominant hand and 89.87% in the nondominant hand) lowers the ability to resist isometric tensions during the bout. In line with this, Bonitch-Góngora et al. (8) analyzed the changes in gripping ability by measuring the effect of performing repeated maximal isometric contractions with the dominant hand performing 10 seconds of a maximal isometric contraction separated by a 10-second recovery period. They found a 39% decrease in maximal isometric handgrip strength (p < 0.000) in a group of 15 Austrian national-level judo athletes. The decrease in handgrip strength after the third repetition was found to be to <80% of the maximal isometric strength (p < 0.05), with no further major changes occurring after the seventh repetition. The results of this study show that the maximum grip strength for the bout does not fall <83% of the maximal isometric strength in any case. This smaller reduction of maximal isometric strength using our protocol, compared with that found using the above-mentioned intermittent protocols, could be because of the grip strength during the bout being submaximal. This results in lower fatigue levels with respect to those generated during intermittent work in which each contraction is maximal. Similarly, Yamaji et al. (62) reported that the rate of grip strength loss increases when working at 100% of the maximal isometric strength. The intensity of the grip's maximal isometric strength when performing the kumi-kata in judo cannot be calculated precisely because of a ban on using any type of instrumentation during a contest. Furthermore, the intermittent nature of the bout, together with technical variations and other aspects which affect performance, means that the grip intensity of hands may vary. The variation in grip intensity affects the resistance and recovery times for this type of contraction (10,51). For these reasons, the specific nature of this research, reproducing the characteristics of a real judo competition, makes these data valuable for the understanding of the behavior of maximal isometric grip strength. With respect to the differences between both hands as a result of successive bouts observed in this study, the importance of the initial maximal isometric strength value may well be different for each hand, because each has a different role during the bout and their fatigability may also depend on different factors.
Only one previous investigation (32), which simulates a judo tournament with each bout separated by a 15-minute recovery period, similarly found a decrease in the first and second postbout maximal isometric handgrip strength for both hands. In its detailed analysis, maximal isometric handgrip strength was found to decrease for both hands by >5% in the first postbout and by 15% in the second postbout. In our research, the maximal isometric handgrip strength decrease per bout was 12.57 and 14.80% for the dominant hand and 10.25 and 13.11% for the nondominant hand in the first and second bouts, respectively. These decreases are significant for the dominant hand in all contests when considering the p value of 0.074 for the second bout as being a significant decrease. The nondominant hand only shows a significant drop in the first postbout, although it is close to being significant for the second (p = 0.054). This therefore indicates greater difficulty for the nondominant hand to recover between bouts than for the dominant hand. Furthermore, the nondominant hand shows a lower difference between values of prebout and postbout maximal isometric handgrip strength. As can be seen in Table 2, the maximal isometric handgrip strength of prebouts follows a different dynamic to that of postbouts. Where there appears to be a stable lower limit for the maximal isometric handgrip strength of postbouts (83–87% of the maximal isometric strength; p > 0.05), the accumulated fatigue means that the maximal isometric handgrip strength of prebouts is progressively lower. This drop becomes significant for the third and fourth bouts with respect to the first bout for both hands, although more so for the nondominant hand.
With respect to other combat sports, Kraemer et al. (38) investigated the physiological responses and performance in a simulated freestyle wrestling tournament. These authors conducted a tournament of 2 days' duration, in which 5 matches in total were carried out (3 matches during the first day and 2 during the second). Immediately before and after the matches, the fighters performed a battery of tests including a test of grip strength using a dynamometer. All the values of grip strength were significantly lower than the initial reference value (baseline). In addition, values recorded after fights 1–3 were significantly lower than the corresponding values recorded before. In agreement with the findings of our study, these data show isometric grip force fatigability in a combat sport with grip with physiological and performance implications and characteristics of temporary structure and technical tactics that are very similar to those of judo.
Our study is novel in that it investigates the relationship of this decline in isometric grip force and the lactic acid concentration in blood and the different degree of influence it has in the fatigability of the dominant and nondominant hands. We recorded very high concentrations of blood lactate after the contests (18.12 ± 4.40 mmol·L−1), which is within the range reported in other studies involving judo athletes of a similar level (between 13 and 18 mmol·L−1) (6,11,12,25,50), demonstrating the eminently anaerobic nature of judo. Associated with the large increase in blood lactate concentration, there is a significant alteration in the acid-base balance of the body from each fight (6). This fact has been demonstrated to affect the contractile ability of the muscles. Therefore, although judo athletes may adapt through improvement of several mechanisms of intercellular and intracellular buffering (e.g., sodium bicarbonate) (25), our findings show an important relationship between the drop in maximal isometric handgrip strength of postbouts and the Lac14 values obtained after each bout (Table 4). This correlation can be seen for all cases when comparing maximal isometric handgrip strength of postbouts with the corresponding Lac14 value for the dominant hand and when comparing Lac14 and the maximal isometric handgrip strength of prebouts for the following bout for the same hand.
Our findings enable us to confirm for the first time the differences discussed above regarding the maximal isometric strength dynamics for each hand and their recovery and the reasons for fatigue. In the sample analyzed, the dominant hand shows a force resistance profile that appears to depend on peripheral muscle fatigue-related factors, such as metabolic acidosis (35). By contrast, the nondominant hand shows a profile that depends to a greater extent on the quality of the isometric contraction during the grip, which is less resistant, and also on neuromuscular activity (52). When this type of muscle contraction (>90–95% of the maximal isometric strength) is maintained for any length of time, the concentration of adenosine triphosphate and phosphocreatine in muscle drops to <30% (3) and the anaerobic lactic contribution decreases (45), because of the nature of its intensity-time relationship. By contrast, when the contraction is less intense allowing periodic increases in blood flow to the muscle, the increase in lactate concentration is greater (120 mmol·kg−1 dry muscle at 25–60 vs. 90–95% of the maximal isometric strength) (54) and its contribution to peripheral fatigue while gripping is more likely (10,34).
The results of this study suggest that a judo bout significantly reduces the maximal isometric strength of both hands. The fatigue resulting from 4 successive bouts affects the maximal gripping strength that each hand can generate differently, with the dominant hand being more resistant and recovering better than the nondominant one. There is an inverse and significant relationship between the maximal isometric handgrip strength of postbouts and the posteffort lactic acid concentrations, with this relationship being more stable for the dominant hand than for the nondominant one and the latter appearing to be less dependent on peripheral muscle fatigue-related factors.
These findings are the first to characterize sports-specific changes in grip strength that occur with several bouts of judo and relate them to the blood lactic acid levels, highlighting specific issues and providing additional information to coaches and trainers for the design of training regimens to improve judo performance. The gripping techniques in judo (kumi-kata) are very important tactical aspects, which often determine the result of the bout (18,26,40), and may depend on the peak grip strength and the endurance of a grip strength. Nevertheless, because elite judo athletes do not demonstrate peak grip strength values superior to those of nonelite judo athletes (21) or to those of nonjudo athletes (30), resistance to a loss of grip strength would seem to be more important for a successful grip during a judo bout or series of bouts (8,23). Therefore, given the importance of achieving kumi-kata in judo, it is recommended that the design of a training regime is directed for maximal isometric handgrip strength, and most importantly, for strength-resistance of the flexor muscles in the forearms. This will ultimately assist judo coaches to better understand forearm muscle physiology during successive judo bouts and to optimize results.
We are grateful for the assistance of Cristóbal Sánchez, Ignacio Chirosa Ríos, Gertrudis Vargas, Maria Ángeles Granados, José Manuel Heredia, Zuleiva García, and Miguel Ángel Pintor.
1. Ahmaidi S, Granier P, Taoutaou Z, Mercier J, Dubouchaud H, Prefaut C. Effects of active recovery on plasma lactate and anaerobic power following repeated intense exercise. Med Sci Sports Exerc 28: 450–456, 1996.
2. Alvim J. Judo
: Nague-Waza. Campinas, Brazil: Papirus, 1975 .
3. Bangsbo J, Johansen L, Quistorff B, Saltin B. NMR and analytic biochemical evaluation of CrP and nucleotides in the human calf during muscular contraction. J Appl Physiol 74: 2034–2039, 1993.
4. Blackwell JR, Kornatz KW, Heath EM. Effect of grip span on maximal grip force and fatigue
of flexor digitorum superficialis. Appl Ergonom 30: 401–405, 1999.
5. Bogdanis GC, Nevill ME, Lakomy HKA. Effects of previous dynamic arm exercise on power output during repeated maximal spring cycling. J Sports Sci 12: 363–370, 1994.
6. Bonitch-Domínguez J, Bonitch-Góngora J, Padial P, Feriche B. Changes in the peak leg-power induced by successive judo
bouts and their relationship to lactate production. J Sports Sci 28: 1527–1534, 2010.
7. Bonitch-Domínguez J, Ramírez J, Femia P, Feriche B, Padial P. Validating the relation between heart rate and perceived exertion in a judo
competition. Med Sport 58: 23–28, 2005.
8. Bonitch-Góngora J, Bonitch-Domínguez J, Feriche B, Chirosa I, Sánchez C, Granados MA, García Z, Pintor MA, Padial P. Análisis del comportamiento de la resistencia a la fuerza isométrica máxima de la musculatura prensora del antebrazo en judokas. In: XII Congress of the Spanish Sports Medicine Federation (FEMEDE), 2007.
9. Borges NG Jr, Domenech SC, Silva ACK, Dias JA, Sagawa Junior Y. Comparative study of maximum isometric grip strength in different sports. Braz J Kineanthropom Hum Perform 11: 292–298, 2009.
10. Byström SEG, Kilbom A. Physiological response in the forearm during and after isometric intermittent handgrip. Eur J Appl Physiol 60: 457–466, 1990.
11. Callister R, Callister RJ, Staron RS, Fleck SJ, Tesch P, Dudley GA. Physiological characteristics of elite judo
athletes. Int J Sports Med 12: 196–203, 1991.
12. Callister R, Fleck SJ, Dudley GA. Physiological and performance responses to overtraining in elite judo
athletes. Med Sci Sports Exerc 22: 816–824, 1990.
13. Castarlenas JL, Planas A. Study of the temporary structure of the judo
combat. Apunts: Educ Fís Deportes 47: 32–39, 1997.
14. Claessens A, Beunen G, Wellens R, Geldof G. Somatotype and body structure of world top judoists. J Sports Med Phys Fitness 27: 105–113, 1987.
15. Degoutte F, Jouanel P, Filaire E. Energy demands during a judo
match and recovery. Br J Sports Med 37: 245–249, 2003.
16. Durnin JVGA, Womersley J. Body fat assessed from total body density and its estimation from skinfold thickness: measurements on 481 men and women aged from 16 to 72 years. Br J Nutrition, 32: 77–97, 1974.
17. Eksioglu M. Relative optimum grip span as a function of hand anthropometry. Int J Ind Ergonom 34: 1–12, 2004.
18. Farmosi I. Body composition, somatotype and some motor performance of judoists. J Sports Med 20: 431–434, 1980.
19. Feriche B, Delgado M, Calderón C, Lisbona O, Chirosa I, Miranda MT, Fernández JM, Álvarez J. The effect of acute moderate hypoxia on accumulated oxygen deficit during intermittent exercise in nonacclimatized men. J Strength Cond Res 21: 413–418, 2007 .
20. Franchini E, Moraes Cássio de, Bertuzzi R, Takito MY, Kiss MAPDM. Effects of recovery type after a judo
match on blood lactate and performance in specific and non-specific judo
tasks. Eur J Appl Physiol 107: 377–383, 2009.
21. Franchini E, Takito MY, Kiss M, Sterkowicz S. Physical fitness and anthropometrical differences between elite and non-elite judo
players. Biol Sport 22: 315–328, 2005.
22. Franchini E, Takito MY, Matheus L, Vieira DEB, Kiss MAPDM. Composição corporal, somatotipo e força isométrica em atletas da seleção brasileira universitária de judo
. Ambito Medicina Desportiva 3: 21–29, 1997.
23. Franchini E, Del Vecchio FB, Matsushigue KA, Artioli G. Physiological profiles of elite judo
athletes. Sports Med 41: 147–166, 2011.
24. Franchini E, Nunes AV, Moraes JM, Del Vecchio FB. Physical fitness and anthropometrical profile of the Brazilian male judo
team. J Physiol Anthropol 26: 59–67, 2007.
25. Franchini E, Takiko MY, Nakamura FY, Matsushigue AK, Peduti Dal'molin MA. Effects of recovery type after a judo
combat on blood lactate removal and on performance in an intermittent anaerobic task. J Sports Med Phys Fitness 43: 424–431, 2003.
26. Franchini E, Takito MY, Nakamura FY, Regazzini M, Matsushigue KA, Kiss MAPDM. Influência da aptidão aeróbia sobre o desempenho em uma tarefa anaeróbia láctica intermitente. Motriz 5: 58–66, 1999.
27. García JM. Análisis diferencial entre los paradigmas experto-novatos en el contexto del alto rendimiento deportivo en Judo
. Thesis, University of Castilla la Mancha, Toledo, Spain, 2004.
28. Gorostiaga EM. Energetic cost of judo
combat. Apunts: Educ Fís Deportes 25: 135–139, 1988.
29. Gülke J, Wachter NJ, Katzmaier P, Ebinger T, Mentzel M. Detecting submaximal effort in power grip by observation of the strength distribution pattern. J Hand Surg 32: 677–683, 2007.
30. Heyward VH. Advanced Fitness Assessment and Exercise Prescription. Champaign (IL): Human Kinetics, 1997 .
31. Hogan MC, Welch HG. Effect of varied lactate levels on bicycle ergometer performance. J Appl Physiol 57: 507–513, 1984.
32. Iglesias E, Clavel I, Dopico J, Tuimil JL. Acute effect of the specific effort of judo
on different strength manifestations and their relation with the reached cardiac frequency during the confrontation. Rendimientodeportivo.com, 6 [digital journal]. Retrieved from http://www.rendimientodeportivo.com/N006/Artic027.htm
33. Imrhan SN. Two-handed static grip strengths in males: The influence of grip width. Int J Industr Ergonom 31: 303–311, 2003.
34. Karlsson J, Bonde-Petersen F, Henriksson J, Knuttgen HG. Effects of previous exercise with arms or legs on metabolism and performance in exhaustive exercise. J Appl Physiol 38: 763–767, 1975.
35. Kent-Braun JA. Central and peripheral contributions to muscle fatigue
in humans during sustained maximal effort. Eur J Appl Physiol 80: 57–63, 1999.
36. Klausen K, Knuttgen HG, Foster HV. Effect of pre-existing high blood lactate concentration on maximal exercise performance. Scand J Clin Lab Invest 30: 415–419, 1972.
37. Koley S, Yadav MK. An association of hand grip strength with some anthropometric variables in Indian cricket players. Phys Educ Sport 7: 113–123, 2009.
38. Kraemer WJ, Fry AC, Rubin MR, Triplett-Mcbride T, Gordon SE, Koziris LP, Lynch JM, Volek JS, Meuffels DE, Newton RU, Fleck SJ. Physiological and performance responses to tournament wrestling. Med Sci Sports Exerc 33: 1367–1378, 2001.
39. Leyk D, Gorges W, Ridder D, Wunderlich M, Rüther T, Sievert A, Essfeld D. Hand-grip strength of young men, women and highly trained female athletes. Eur JAppl Physiol 99: 415–421, 2007.
40. Little NG. Physical performance attributes of junior and senior women, juvenile, junior and senior men judokas. J Sports Med Phys Fitness 31: 510–520, 1991.
41. MacDougal J, Wenger H, Green H. Evaluación Fisiológica del Deportista. Barcelona, Spain: Paidotribo, 1995.
42. Marcon G, Franchini E, Vieira DEB, Barros TL. Time structure and activities performed during a judo
match. In: Annals of the 5th International Judo
Federation World Research Symposium. Del'Vecchio FB, Franchini E, eds. International Judo
Federation, 2007. p. 49.
43. Matsumoto Y, Ogawa S, Asami T, Furuta Y, Ishiko T, Kawamura T, Masuda M. A followup study of the physical fitness of judoists (report I and II). Bull Assoc Sci Stud Judo
4: 1–26, 1972.
44. Nicolay CW, Walker AL. Grip strength and endurance: Influences of anthropometric variation, hand dominance, and gender. Int J Ind Ergonom 35: 605–618, 2005.
45. Sahlin K. Intracellular pH and energy metabolism in skeletal muscle of man. Acta Physiol Scand 455: 1–56, 1978.
46. Sanchis C, Suay F, Salvador A, Llorca J, Moro M. Una experiencia en la valoración fisiológica de la competición de judo
. Apunts 28: 51–58, 1991.
47. Sande LP, Coury HJCG, Oishi J, Kumar S. Effect of musculoskeletal disorders on prehension strength. Appl Ergonom 32: 609–616, 2001.
48. Sbriccoli P, Bazzucchi I, Di Mario A, Marzattinocci G, Felici F. Assessment of maximal cardiorespiratory performance and muscle power in the Italian Olympic judoka. J Strength Cond Res 21: 738–744, 2007.
49. Sikorski W, Mickiewicz G, Majle B, Laksa C. Structure of the contest and work capacity of the judoist. In: European Judo
Union Proceedings of the International Congress on Judo
‘‘Contemporary Problems of Training and Judo
Contest’’. Spala, Poland: European Judo
Union, 1987. pp. 58–65.
50. Sitkowski D. Some indices distinguishing Olympic or World Championship medalists in sprint kayaking. Biol Sport 19: 133–147, 2002.
51. Sjøgaard G, Savard G, Juel C. Muscle blood flow during isometric activity and its relation to muscle fatigue
. Eur J Appl Physiol 57: 327–335, 1988.
52. Speed CA, Campbell R. Mechanisms of strength gain in a handgrip exercise programme in rheumatoid arthritis. Rheumatol Int, Advance online publication. 2010.
53. Szygula Z, Gawronski W, Kalinski M. Fatigue
during exercise. Med Sport 7: 57–67, 2003.
54. Taylor AW, Brassard L. A physiological profile of Canadian judo
team. J Sports Med Phys Fitness 21: 160–164, 1981.
55. Thomas SG, Cox MH, Legal YM, Verde TJ, Smith HK. Physiological profiles of the Canadian national judo
team. Can J Sport Sci 14: 142–147, 1989.
56. Tredgett MW, Davis TRC. Rapid repeat testing of grip strength for detection of faked hand weakness. J Hand Surg 25: 372–375, 2000.
57. Tumilty D, Hahn A, Telford RD. A physiological profile of well-trained male judo
players, with proposals for training. Excel 2: 12–14, 1986.
58. Van Malderen K, Jacobs C, Ramon K, Evert Z, Deriemaeker P, Clarys P. Time and technique analysis of a judo
fight: a comparison between males and females. In: Book of Abstracts of the 11th Annual Congress of the European College of Sport Science. Hopeler H ., eds. 2006. p. 101.
59. Walker S, Siddiqi T, Amundsen L. Measurement of hand grip fatigueIn: Proceedings of the Annual Conference of the American Physical Therapy Association (APTA), Available at: APTA Journal Website, www.ptjournal.org
, June 2002.
60. Watanabe T, Owashi K, Kanauchi Y, Mura N, Takahara M, Ogino T. The short-term reliability of grip strength measurement and the effects of posture and grip span. J Hand Surg 30: 603–609, 2005.
61. Wilmore JH, Costill DL. Fisiología del Esfuerzo y del Deporte. Barcelona, Spain: Paidotribo, 2004.
62. Yamaji S, Demura S, Nagasawa Y, Nakada M. The influence of different target values and measurement times on the decreasing force curve during sustained static gripping work. J Physiol Anthropol 25: 23–28, 2006.
63. Yates JW, Gadden B, Cresanta MK. Effects of prior dynamic leg exercise on static effort of the elbow flexors. J Appl Physiol 55: 891–896, 1983.