European Journal of pApplied hysiology Eur J Appl Physiol (1984) 53:97-105 and Occupational Physiology 9 Springer-Verlag 1984 Neuromuscular, anaerobic, and aerobic performance characteristics of elite power athletes K. H/ikkinen 1, M. Al6n 2, and P. V. Komi 1 1 Department of Biology of Physical Activity, University of Jyvfiskyl~i, SF-40100 Jyvfiskylfi 10 2 Department of Health Sciences, University of Jyvfiskylfi, SF-40100 Jyvfiskylfi 10 Research Unit for Sport and Physical Fitness, SF-40700 Jyv/iskyl~ 70, Finland Summary. Various aspects of neuromuscular, anaerobic, and aerobic performance capacity were investigated in four powerlifters, seven bodybuilders, and three wrestlers with a history of specific training for several years. The data (means + SD) showed that the three subject groups possessed similar values for maximal isometric force per unit bodyweight (50.7 + 9.6, 49.3 + 4.1, and 49.3 + 10.9 N/kg, respectively). However, significant (P < 0.05) differences were observed in the times for isometric force production, so that e.g., times to produce a 30% force level were shorter for the wrestlers and bodybuilders (28.3 + 3.1 and 26.4 + 6.6 ms) than that (53.3 + 23.7 ms) for the powerlifters. Utilization of elastic energy by the wrestlers was significantly (P < 0.05) better than that of the other two subject groups, as judged from differences between the counter-movement and squat jumps at 0, 40, and 100kg's loads. No differences were observed between the groups in anaerobic power in a l-rain maximal test, but the values for Vo2 max were higher (P < 0.05) among the wrestlers and bodybuilders (57.8 + 6.6 and 50.8 + 6.8 ml 9kg -1 9min -1) as compared to the powerlifters (41.9 + 7.2 ml 9kg -1 9min-i). Within the limitations of the subject sample, no differences of a statistical significancy were observed between the groups in fibre distribution, fibre areas, or the area ratio of fast (FT) and slow (ST) twitch fibres in vastus lateralis. In all subjects the vertical jumping height was positively (P < 0.01) correlated with the FT fibre distribution, and negatively with the time of isometric force production (P < 0.05). Maximal force was correlated (P < 0.001) with thigh girth. Muscle cross-sectional area did not correlate with mean fibre area. It was assumed that the selected aspects of neuromuscular, anaerobic, and aerobic performance capacity may be Offprint requests to: K. H/ikkinen at the above address influenced by muscle structure, but also specifically and/or simultaneously by training lasting for several years. Key words: Neuromuscular performance - Anaerobic power - Aerobic capacity - Strength training Muscle hypertrophy Introduction Powerlifting, bodybuilding, and wrestling are events which all place special demands on the entire neuromuscular system. Maximal voluntary force production in these athletes is therefore high (MacDougall et al. 1982). In addition, the physiological requirement is expected to be demanding, both anaerobically and aerobically. The influence of different training stimuli on the neuromuscular system can, however, be characterized by changes in maximal strength (Komi and Buskirk 1972; Hfikkinen and Komi 1981), in isometric force-time characteristics (Hfikkinen et al. 1980, 1981; Viitasalo et al. 1981b) and in force-velocity curves (Ikai 1970; Caiozzo et al. 1981). The elastic properties of the muscles may also be under the influence of special training (Bosco and Komi 1982). A limited amount of information is, however, available regarding the influence of several years of special training on various aspects of neuromuscular performance. On the other hand, it is well known that anaerobic and aerobic performance capacities differ between various sportsmen and events (Komi et al. 1977; Rusko et al. 1978). It is of physiological interest to know how these performance traits compare with those of neuromuscular performance in powerlifters, bodybuilders, and wrestlers who differ in their training backgrounds. It is well documented that when a skeletal muscle is subjected to a high intensity training programme, 98 K. Hfikkinen et al.: Performance characteristics of elite power athletes e.g., in powerlifting and bodybuilding, it responds to these loads by increasing the cross-sectional area of the muscle (Tesch and Larsson 1982). In humans it has been shown that this increase in total muscle size is in part due to the enlargement of both fast (FT) and slow twitch (ST) fibres with a greater degree of hypertrophy occurring in the FT fibres (Thorstensson 1976; MacDougall et al. 1980; Hfikkinen et al. 1981; Komi et al. 1982). However, less is known about the time course of training induced hypertrophy or of its limits. The present investigation was undertaken to examine the influence of specific long-term exercise stress on various aspects of neuromuscular, and anaerobic, and aerobic performances, and of histochemical muscle fibre characteristics in powerlifters, bodybuilders, and wrestlers. Methods Subjects The male subjects volunteered for the study were four powerlifters, seven bodybuilders, and three wrestlers of Finnish national level. They had been training for competitive activity in their special sports event for an average of 6.5 years. Of the 14 subjects, 10 were among the three best athletes in their particular sports in Finland, and the remaining four subjects were of lower national level. Table 1 presents the physical characteristics of the subject groups. Testing Neuromuscular performance. As a functional performance test of maximal force, the barbell squat lift was used. In this test the subject raised himself up from a full squat position with load on his shoulders. The trunk were kept straight, and no preliminary countermovement was allowed (Hfikkinen and Komi 1981). An electromechanical dynamometer (Komi 1973) was used to measure the maximal bilateral isometric force and various force-time and relaxation-time parameters of the leg extensor muscles. The testing contractions were performed at knee and hip angles of 100~ and 110~, respectively. The subjects were carefully instructed to perform the contractions at the maximally produced rate of force development as well as to relax after the contraction as quickly as possible. The force in each contraction was recorded on magnetic tape (Racal Store 7) and analyzed with a HP 21MX computer system. In the force-time analyses (Hfikkinen et al. 1980), in the relative scale, the times needed to increase the force from 10% to 30%, 60%, and 90% were calculated. In the absolute scale the corresponding calculations were performed from the force level of 100 N to that of 500, 1,500, and 2,500 N. In addition the maximal rate of force development (N/s) was calculated (Viitasalo et al. 1980). The relaxation-time curve was analyzed in the relaxation phase of the contraction with a starting force level of 85% (Viitasalo et al. 1980). The times needed to relax the force to 60%, 30%, and 10% as well as the rate of maximal relaxation (N/s) were cal,zulated. In addition to the isometric measurements, various maximal voluntary vertical jumps were tested on a force-platform (Komi et al. 1974). The tests included a squat jump (SJ) from a static semisquatting position with no preliminary countermovement, and a countermovement jump (CMJ) from a standing position with a preliminary countermovement (Komi and Bosco 1978). In all jumping conditions, the subjects kept their hands on the hips throughout the entire jump. In addition to this the subjects performed the respective squat and countermovement jumps with the load (Bosco and Komi 1979b). In these jumps on the force-platform the barbell was kept on the shoulders and loads of 20, 40, 60, 80, and 100 kg were used. The hands were gripped tightly on the barbell during these jumping conditions. Finally the subjects were tested on the force-platform by various drop jumps. In these tests the subjects dropped from heights of 20, 40, 60, 80, and 100 cm onto the platform with subsequent jumps upwards (Komi and Bosco 1978). From these drop jumps the best dropping height (BDH) and height of rise of the center of gravity in the best drop jump (BDJ) were also calculated. The former denoted the average dropping height which gave the highest performance which was described by the latter. All the jumping performances of the study were recorded on magnetic tape. The flight time measured from the force signal was used for calculating the height of rise of the body center of gravity [h(C.G.)] (Asmussen and Bonde-Petersen 1974; Komi and Bosco 1978). Anaerobic performance. The anaerobic power of the subjects was tested by a one-minute maximal bicycle ergometer (Monark) test (Sz6gy and Cherebetiu 1974). The friction force on the ergometer was 1/13 of the body weight of the subject. The power output (W x kg -1) was calculated using the number of revolutions and the frictional resistance. Aerobic performance, Max Vo2 was determined on the bicycle ergometer. The intensity of exercise was increased every 2nd min in the beginning b.y 60 W and in the end by 30 W until exhaustion. Oxygen uptake (Vo2) was measured using an automated system (Beckman MMC). The highest value during the test was taken as the maximum oxygen uptake. Physical characteristics. In the anthropometric measurements the percentage of fat in the body and the fat-free weight were estimated from the measurements of skinfold thickness (Durnin and Rahaman 1967). The measurements of the thigh and arm girths were obtained with a tape applied around the relaxed muscles. The mean values of the right and left thigh and arm were taken as maximum girths. Muscle fibre characteristics. Muscle biopsies were obtained from the vastus lateralis muscle with a needle biopsy technique (Bergstr6m 1962). Histochemical staining for myofibrillar ATPase (Padykula and Herman 1955) were used to classify the fibres as fast twitch (FT) or slow twitch (ST) (Gollnick et al. 1972). For the calculation of fibre areas and the FT/ST area ratio, 10 representative fast and 10 slow cells were selected. This selection always took place from the same area, in which the cross-section appeared perpendicular to the fibre orientation. The sample was reflected by a microscope onto a digital board which was connected to a computer. The outlines of the cells were stored in the system, which calculated the average cell areas for the FT and ST cell groups separately (Viitasalo and M~kkinen 1980). From the FT% and FT/ST values the relative area occupied by the FT cells in the total fibre area was calculated (%FT fibre area; Viitasalo et al. 1980). Statistical methods. Standard statistical methods were used for the calculation of means, standard deviations, standard errors, and coefficients of correlation. Differences between the values of the subject groups were tested for significance by Student's t-test. K. Hfikkinen et al.: Performance characteristics of elite power athletes Results Physical characteristics Table 1 presents the physical characteristics of the three subject groups. The mean age, mass, height, fat-free weight, and thigh girth did not differ significantly between the groups. The percentage of body fat of the wrestlers was 12.7 + 5.4, which was significantly (P < 0.05) less than the respective value of 19.9 + 5.4 of the powerlifters, but similar to that of t3.4 4- 3.9 of the bodybuilders. The arm girth of the bodybuilders was 39.0 + 2.6 cm, which was significantly greater than those of 37.1 4- 1.7 cm (P < 0.05) and 32.8 + 3.1 cm (P < 0.01) of the powerlifters and wrestlers respectively. 99 42.0 + 12.5, respectively, but the values did not differ significantly. The mean areas of FT and ST muscle fibres were similar in all of the three groups, as well as the FT/ST area ratios and the % F T fibre areas, as shown in Table 2. Neuromuscular performance The results of maximal forces and isometric force-time and relaxation-time curves are presented in Table 3. No group differences were observed in the maximal force parameters. The values of maximal bilateral isometric force per bodyweight (N/kg) were 50.7 + 9.6, 49.3 _+ 4.1, and 49.3 _+ 10.9, respectively, for the powerlifters, bodybuilders, and wrestlers. The average force-time curves both in the relative and absolute scales differed between the groups, so that the times to produce certain submaximal forces were significantly (P < 0.05-0.01) longer in the powerlifters than in the other two groups. Figure i presents the Muscle fibre characteristics The FT percentage of the powerlifters, bodybuilders, and wrestlers were 60.0 _+ 13.3, 58.6 _+ 13.1, and Table 1. Physical characteristics of the subject groups. The values indicate the mean + SD Variable Age (years) Mass (kg) Height icm) Fat (%) Fat-free weight (kg) Thigh girth (cm) Arm girth (cm) Subject groups Significance of difference Powerlifters (PL) (n = 4) Bodybuilders (BB) (n = 7) Wrestlers (W) (n = 3) Mean SD Mean SD Mean SD 25.5 89.4 i73.6 19.9 71.4 60.7 37.1 5.0 7.3 5.0 5.4 4.8 1.5 1.7 25.6 87.6 176.9 13.4 75.8 60.4 39.0 5.2 6.3 3.4 3.9 5.8 2.4 2.6 24.0 77.5 173.3 12.7 67.1 56.7 32.8 2.0 17.0 10,5 5.4 10.4 6.1 3.1 NS NS NS PL/BB: P < 0.05 NS NS PL/BB: P < 0.05 BB/W: P < 0.01 Table 2, Muscle fibre characteristics of the subject groups. The analysis was performed from the biopsy samples taken from the vastus lateralis muscle. The fibre areas represent arbitrary but in relative terms correct values. The absolute values could not be computed because of unavailability of an appropriate calibration method in the computerized analysis Variable FT% FT area (arbitrary units) ST area (arbitrary units) FT/ST area ratio %FT area Subject groups Significance of difference Powerlifters ( n - 4) Bodybuilders (n = 7) Wrestlers (n = 3) Mean SD Mean SD Mean SD 60.0 2.86 13.3 0.16 58.6 3.57 13.1 1.18 42.0 2.66 12.5 0.35 NS NS 2.24 0.28 2.45 0.65 2.26 0.38 NS 1.29 76.7 0.16 23.3 1.34 73.6 0.23 24,1 1.18 48.7 0.12 11.2 NS NS ]+0 i +~ 100 90 .....5 (%} 0 # ,~, i entire force-time curves for all the three groups. In the relaxation phase of the isometric contraction the only difference (P < 0.05) between the groups was in the time to relax the force to 10%, which was shorter in the wrestlers (75.5 +_ 4.1 ms) than in the powerlifters (151.8 + 53.1 ms). The heights of rise of the center of gravity of the subject groups in the squat, countermovement, and drop jumps are shown in Table 4. No group differences were observed in these results and the highest performances were observed in CMJ in all of the subject groups. The average values of CMJ for the powerlifters, bodybuilders, and wrestlers were FORCE/WEIGHT (N/kg) ~ 60 30 K. Hfikkinen et al.: Performance characteristics of elite power athletes 40 i i 0 i 200 i i 400 1.~" i 600 TIME ( m s ) Fig. 1. Average isometric force-time curves in the relative scale and average values for maximal isometric force per weight of the subject groups. The force-time curves are drawn as a function of time up to a force level of 90% of maximum. (A = powerlifters, 9 = bodybuilders, [] = wrestlers) LOAD (kg) ~ 100" 80 50 A0 LOAD (kg) [ifters LOAD (kg) BodybuiLders 100 2O 0 80 60 60 40 40 20 20 SJ ~o-'u 0 7;, i 10 i I i 20 30 40 HEIGHT OF RISE OF C.G. i 100 80 ~,, i 10 i i i 20 30 40 HEIGHT OF RiSE OF CO. (cm) Fig. 2. Average load-vertical jumping height (of rise of center of gravity) curves in the squatting (SJ) and countermovement (CMJ) jumping conditions of the subject groups 0 I i i i 10 20 30 / I 40 HEIGHT OF RISE OF C O (cm) (cm) Table 3. Maximal muscle strength, isometric force-time, and force-relaxation characteristics of the subject groups Variable Subject groups Significance of difference Powerlifters (n = 4) Mean Squat lift (kg) Maximum bilateral isometric strength (N) Isometric strength/ body mass (N/kg) SD Bodybuilders (n = 7) Wrestlers (, = 3) Mean Mean SD SD 207.5 4,492.0 34.3 655.2 183.0 4,329.7 23.6 590.4 147.5 3,229,0 37.3 1,730.3 NS NS 50.7 9.6 49.3 4.1 49.3 10.9 NS 3O% 53.3 23.7 26.4 6.6 28.3 3.1 60% 151.0 39.8 96.3 21.2 91.3 29.9 90% 633.3 137.5 392.6 118.6 308.7 94.6 500 N 1,500 N 2,500 N 40.5 103.8 184.3 21.9 52.5 80.9 22.0 55.4 116.7 6.2 11.5 24.3 24.7 67.0 188.0 3.5 16.1 85.8 Force-times (ms) Rate of maximal force development ( N / s ) Relaxation-times (ms) 60% 30% 10% Rate of maximal relaxation (N/s) 26,568 26.0 59.5 151.8 49,050 12,042 4.2 10.5 53.1 11,406 40,291 26.6 62.3 120.0 49,867 8,359 4.7 13.1 12.0 7,783 31,065 28.7 52.7 75.7 49,863 11,589 7.4 5.5 4.1 18,570 PL/BB: PL/W: PL/BB: PL/W: PL/BB: PL/W: PL/BB: PL/BB: PL/BB: P< P < P < P < P < P < P< P< P< 0.01 0.05 0.01 0.05 0.05 0.05 0.05 0.05 0.05 NS NS NS PL/W: NS P < 0.05 K. Hfikkinen et al.: Performance characteristics of elite power athletes 39.0 _+ 9, 44.4 + 5, and 42.7 + 6 cm, respectively. Figure 2 presents the average load-jumping height curves of the three groups in the SJ and CMJ conditions. Figure 3 demonstrates the difference in performance between CMJ and SJ. This difference was always greatest in the wrestlers, as compared with the powerlifters and bodybuilders. At the 0, 40, and 100 kg loads this difference was statistically significant (P < 0.05). Anaerobic and aerobic performance Table 5 presents the results of anaerobic power and max I)o2. No group differences were observed in anaerobic power. During the 1-min test the average power values (W. kg -1) of the powerlifters, bodybuilders, and wrestlers were 6.4 + 1.0, 6.6 + 0.5, and 7.1 + 0.8 W, respectively. Maximum oxygen uptake (ml. kg -1. min -1) of the wrestlers was 57.8 + 6.6ml, which was significantly ( P < 0.05) higher than that of 41.9 + 7.2 ml for the powerlifters. The respective value of 50.8 + 6.8 ml of the bodybuilders was also greater (P < 0.05) than that of the powerlifters. Table6 summarizes the correlation (cm) 5.0t &.0 3.0 2,0 1.0 0 0 kg 20kg &Okg fiOkg 80kg 101 lOOkg Fig. 3. Mean (+ SE) differences in vertical jumping heights (of rise of center of gravity) between the countermovement and squat jumps (performed with the loads of 0 - 1 0 0 kg) of the subject groups. (A = powerlifters, O = bodybuilders, [] = wrestlers) Table 4. Mean (_+ SD) values of height of center of gravity in squatting (SJ) and countermovement (CMJ) jumps and in dropping (D J) jumps from different dropping heights (20-100 cm) of the subject groups. The best dropping height (BDH) and the best dropping jump (BDJ) are also shown in the table Variable Squat jump (cm) Countermovement jump (cm) Subject groups Significance of difference Powerlifters (n = 4) Bodybuilders (n = 7) Wrestlers (n = 3) Mean Mean Mean SD SD SD 38.0 39.0 7.0 9.2 39.7 44.4 3.2 5.4 37.0 42.7 5.9 6.4 NS NS Dropping jumps (cm) 20 cm 40 cm 60 cm 80 cm 100 cm 28.8 30.3 29.3 29.0 29.0 5.1 4.3 3.8 2.5 2.1 29.6 32.3 33.0 31.7 28.7 3.6 3.2 4.7 3.8 7.2 31.3 31.7 31.7 29.7 29.0 1.0 2.3 6.0 6.5 4.3 NS NS NS NS NS Best dropping height (cm) 50.0 30.0 62.9 39.0 40.0 28.0 NS Best dopping jump (cm) 30.7 1.6 33.9 1.0 33.7 1.6 NS Table 5. Aerobic and anaerobic performance characteristics of the subject groups Variable l)o2max min -1) (1 9 ( m l . k g 1 . m i n ~) Anaerobic power (W. min- 0 (W. kg 1 . min 1) Subject groups Significance of difference Powerlifters (n = 4) Bodybuilders (n = 7) Wrestlers (n = 3) Mean Mean Mean 3.74 41.9 570.5 6.4 SD 0.40 7.2 57.6 1.0 4.44 50.8 577.9 6.6 SD 0.62 6.8 48.3 0.5 4.42 57.8 541.3 7.1 SD 0.58 6.6 71.3 0.8 NS PL/BB: P < 0.05 PL/W: P < 0.05 NS NS K. Hfikkinen et al.: Performance characteristics of elite power athletes 102 6. Correlation coefficients between anaerobic (W. kg-1 . rain-1) and aerobic (ml 9kg-I 9min-1) performance and selected muscle fiber and neuromuscular performance characteristics (n = 14; P < 0.05, r = 0.53) Table FT% %FT area Isometric force/weight Force-time 500 N Anaerobic power Aerobic capacity - 0.02 0.13 0.14 - 0.22 - 0.05 0.08 - 0.01 - 0.35 coefficients between anaerobic and aerobic performance and selected muscle fibre and neuromuscular performance characteristics. No significant correlations were observed. Discussion The present study with the athletes from various power events demonstrated that despite the similarity in maximal strength there can be differences in the time for force production and in utilization of stored elastic energy. In addition, the present data indicate that these various aspects of neuromuscular as well as anaerobic and aerobic performance capacity may be influenced specifically and/or simultaneously by training lasting for several years. The data of the physical characteristics of the subject groups presented in Table 1 are in line with previous experiments (Katch et al. 1980; Spitler et al. 1980) demonstrating that bodybuilders possess big limb circumferences and low per cent body fat. The wrestlers are also known to possess low per cent body fat (Widerman and Hogan 1982) and this was confirmed in the present study. This should also be true with powerlifters, but the present subjects possessed a surprisingly high per cent body fat. These special features of body composition of athletes in power events are obvious reflections of long-term exercise stress and dietary procedures. The present data about muscle fiber characteristics did not demonstrate any differences between the three groups 9 This was true regarding the F T % and the FT and ST fibre areas and their ratio. As could be expected (MacDougall et al. 1982) the average areas of FT fibres were larger than ST areas especially among bodybuilders and powerlifters. A greater degree of hypertrophy of the FT fibres as compared to ST fibres has been shown in several training studies with high resistance loads (MacDougalt et al. 1980; Hfikkinen et al. 1981; Komi et al. 1982). As seen from Table 3 and Fig. 1, the three groups did not differ with respect to maximal voluntary strength, but did show differences in the time for force production. Training of powerlifters involves exercises of high intensity and slow contraction velocity. This is likely to lead to adaptation of the neuromuscular system to produce high forces relatively slowly, as seen from the force-time curve. Possible changes in firing frequencies and/or recruitment patterns (Salmons and Vrbova 1969) of the motor units may have changed the contraction characteristics of the whole muscle or muscle group. Consequently it can be questioned seriously whether the term "powerlifting" is a correct one to characterize the event. On the other hand, the training of bodybuilders and especially that of wrestlers involves more submaximal loads with higher contraction velocities, and adaptation of the neuromuscular system for faster force production may be obvious. These special changes in force-time curve caused by different training stimuli have been demonstrated during controlled training experiments (Hfikkinen et al. 1980, 1981; Viitasalo et al. 1981b). Training of wrestlers involves also various jumping drills etc. which also means the repeated occurrence of stretch-shortening cycles. It has been previously demonstrated (Komi and Bosco 1978) that differences can exist in the utilization of stored elastic energy during stretch-shortening cycles. Figure 3 clearly demonstrates that the wrestlers utilized more elastic energy than the other two subject groups in the present study. In line with this result, it has been shown (H/ikkinen and Komi 1983) that strength training alone does not cause any changes in the elastic properties of the muscle, but it may increase the tolerance for high stretching loads. However, the present results shown in Table 4 failed marginally to demonstrate statistically significant differences in the best dropping heights. The higher values of the wrestlers for 12o2max as compared to the bodybuilders and powerlifters are expected. Training methods and the competitive demands in wrestling differ from those of the other two subject groups in energy production from oxidative processes. In the anaerobic test, on the other hand, there were no significant differences between the groups in energy production from anaerobic glycolysis. One might have expected greater values among the wrestlers than those found (7.1 + 08. vs 6.4 + 1.0, and 6.6 + 0.5 W). The limited number of subjects in the present study and/or the present training background of the subjects may have, however, influenced both the anaerobic and aerobic data. These aspects may also be some of the reasons why the present data failed to conform with the finding of Gollnick et al. (1972) or Rusko et al. (1978) that Vo2max and fibre composition are K. Hfikkinen etal.: Performance characteristics of elite power athletes 103 salo and Komi 1978; Bosco and Komi 1979b; Viitasalo et al. 1981a). The results presented in Fig. 4 are in line with these observations, although effects of training and muscle structure may be mixed and difficult to distinguish from each other. While it is reported that increase in total muscle size is in part due to the enlargement of individual muscle fibres (MacDougall et al. 1980; Hfikkinen et al. 1981; Komi et al. 1982) the time course of training-induced hypertrophy or its limits is less known. In fact, it has been suggested (MacDougall et al. 1982) that there may be an optimal or ceiling size for cross-sectional fibre area for fibres undergoing hypertrophy. This interpretation was made due to the fact that fibre areas in highly trained body-builders did not exceed those in control subjects (see also Tesch and Larsson 1982). Within the limitations of the subject sample and of the methodology for the determination of fibre areas (see Viitasalo and Mfikinen 1980; Viitasalo et al. 1980) the present results tend to support this suggestion. This is due to the observation that there was no significant correlations between mean fiber area and maximal isometric force or thigh girth. Therefore muscle cross-sectional area was not clearly reflected in the present study in mean fibre area (r -- 0.32, NS) (see Hfiggmark et al. 1978; Schantz et al. 1981) but in maximal strength (r = 0.82, see Fig. 4). These results might suggest, in line with some previous reports (MacDougall et al. 1982; Tesch and Larsson 1982), that some degree of fibre hyperptasia may have occurred which may be related to chronic heavy resistance training. interrelated. This was also the case between anaerobic power and the selected neuromuscular variables, which indicates the importance of specific components of neuromuscular and energy yielding processes (see also Komi et al. 1977). It is well documented (Ikai and Fukunaga 1968; Schantz etal. 1983) that muscle cross-sectional area is of importance for maximal voluntary strength. The present results, shown in Fig. 4, tend also to support this, although thigh girth is of course influenced by bone size and the quantity of subcutaneous fat. The relationship between muscle fiber composition and maximal isometric force is, however, somewhat complicated, in part due to the limitations of the method of muscle biopsy for fibre type determination (see Elder et al. 1982; Bomstrand and Ekblom 1982). In some studies (Komi et al. 1977; Tesch and Karlsson 1978), significant positive correlations have been found between maximal isometric force and FT percentage of the muscle, but there are also negative correlations (Kroll et al. 1980) and data (Thorstensson 1976; Viitasalo et al. 1981a) supporting the presence of no correlation at all (see Fig. 4 of the present study). The possible effect of muscle structure on maximal force may therefore be masked by specific training. Moreover, in the isometric contraction time for absolute force production is often very tong, and therefore the type of the working motor units may be of less importance. On the other hand, when the time of force production is short, or high speeds in concentric contractions are used, muscular structure seems to be of greater importance in determinating the rate of force development (Viita- 600084 B 553 iSOMETRIC fORCE/WEiGHF " (N/kg) r~=_:02] ins i 60 0 5000.0/I / oo ~ o $00 55.0 550 o o o 500 o o o c~ Z-0.0 50.0 PERCENT Fig. 4. Interrelations between maximal bilateral isometric force per weight and the FT percentage of the vastus lateralis muscle A, between maximal isometric force and the thigh girth B, between the vertical jumping height of the squat jump and the FT percentage of the vastus lateralis muscle C and between the vertical jumping height of the countermovement jump and time of isometric force production to the force level of 500 N D. (& = powerlifters, O = bodybuitders, [] = wrestlers) o o c~ ~*5Q 500 FT 700 500 FIBRES 55 0 700 THIGH GIRTH ( c m ] O s00 SOUAT (cm) JUMP 550 c~ ~50 o o 35.o 30a i~P~0"O5 450 ! o ~0 500 COUNTER MOVEMENT JUMP (crn) O ~' O 3501 e n= 14 I 30.0 400 50.0 PERCENT 60,0 FT FIBRES 700 J 20.0 ~ 300 i &0.0 i 50.0 L 50.0 ESOMETRIC FORCE-TIME 5OQ N ( m s l 104 K. Hfikkinen et al.: Performance characteristics of elite power athletes In summary, our data indicate that, despite the similarity of maximal strength, differences may be observed in time of force production and in utilization of stored elastic energy. The selected aspects of the neuromuscular as well as anaerobic and aerobic performance capacity may be influenced by muscle structure but also specifically and/or simultaneously by training lasting for several years. Acknowledgements. Supported in part by a grant from the Ministry of Education, Finland. We also thank Miss Pirkko Puttonen, Miss Ursula Salonen, Mr. Ensio Hakala, Mr. Heikki Kauhanen and Mr. Paavo Rahkila for theis skillful technical assistance. References Asmussen E, Bonde-Petersen F (1974) Storage of elastic energy in skeletal muscle in man. Acta Physiol Scand 91 : 358-392 BergstrOm J (1962) Muscle electrolytes in man. Scand J Clin Lab Invest [Suppl] 68 Blomstrand E, Ekblom B (1982) The needle biopsy technique for fiber type determination in human skeletal muscle - a methodological study. Acta Physiol Scand 116:437-442 Bosco C, Komi PV (1979a) Mechanical characteristics and fiber composition of human leg extensor muscles. Eur J Appl Physiol 41 : 275-284 Bosco C, Komi PV (1979b) Potentiation of the mechanical behaviour of the human skeletal muscle through pre-stretching. Acta Physiol Scand 106:467-472 Bosco C, Komi PV (1982) Muscle elasticity in athletes. In: Komi PV (ed) Exercise and sport biology. Human Kinetics Publishers, Champaign, I11, pp 109-117 Caiozzo V, Perinne J, Edgerton V (1981) Training-induced alternations of the in vivo force-velocity relationship of human muscle. J Appl Physiol: Respirat Environ Exerc Physiol 51 : 750-754 Durnin J, Rahaman M (1967) The assessment of the amount of fat in the human body from the measurements of skinfold thickness. Br J Nutr 21:681-689 Elder G, Bradbury K, Roberts R (1982) Variability of fiber distributions within human muscles. J Appl Physiol 53:1473-1480 Gollnick P, Armstrong R, Saubert G, Piehl K, Saltin B (1972) Enzyme activity and fiber composition in skeletal muscle of untrained and trained men. J Appl Physiol 33:312-319 Hfiggmark T, Jansson E, Svane B (1978) Cross-sectional area of the thigh muscle in man measured by computed tomography. Scand J Clin Lab Invest 38:355-360 Hfikkinen K, Komi PV (1981) Effect of different combined concentric and eccentric muscle work regimens on maximal strength development. J Human Mov Studies 7 : 3 3 - 4 4 Hfikkinen K, Komi PV (1983) Alterations of mechanical characteristics of human skeletal muscle during strength training, Eur J Appl Physiol 50:161-172 Hfikkinen K, Viitasalo 3T, Komi PV (1980) Die Wirkung unterschiedlich kombinierter konzentrischer und exzentrischer Muskelarbeit auf Kraft-Zeit-Merkmale der Beinstreckmuskulatur. Leistungssport 10:374-381 Hfikkinen, K, Komi PV, Tesch P (1981) Effect of combined concentric and eccentric strength training and detraining on force-time, muscle fibre, and metabolic characteristics of leg extensor muscles. Scand J Sports Sci 3 : 5 0 - 5 8 Ikai M (1970) Training of muscle strength and power in athletes. Presented at the FIMS Congress, Oxford Ikai M, Fukunaga T (1968) Calculation of muscle strength per unit cross-sectional area of human muscle by means of ultrasonic measurements. Int Z Angew Physiol 26 : 26-32 Katch V, Katch F, Moffatt R, Gittleson M (1980) Muscular development and lean body weight in bodybuilders and weightlifters. Med Sci Sports 12:340-344 Komi PV (1973) A new electromechanical ergometer. 3. Int. Seminar fiir Ergometrie, Berlin Komi PV, Buskirk E (1972) Effect of eccentric and concentric muscle conditioning on tension and electrical activity of human muscle. Ergonomics 15 : 417-434 Komi PV, Bosco C (1978) Utilization of stored elastic energy in leg extensor muscles by men and women. Med Sci Sports 10 : 261-265 Komi PV, Luhtanen P, Viljamaa K (1974) Measurement of instantaneous contact forces on the force-platform. Research Reports from the Department of Biology of Physical Activity, University of Jyvfiskylfi, Finland [No 5] Komi PV, Rusko H, Vos J, Vihko V (1977) Anaerobic performance capacity in athletes. Acta Physiol Scand 100:107-114 Komi PV, Karlsson J, Tesch P, Suominen H, Heikkinen E (1982) Effects of heavy resistance and explosive type strength training methods on mechanical, functional and metabolic aspects of performance. In: Komi PV (ed) Exercise and sport biology. Human Kinetics Publishers, Champaign, Ill, pp 90-102 Kroll W, Clarkson P, Kamen G, Lambert J (1980) Muscle fibre type composition and knee extension isometric strength fatigue patterns in power- and endurance-trained males. Res Quarterly Exercise Sport 51 : 323-333 MacDougall J, Elder G, Sale D, Moroz J, Sutton J (1980) Effects of strength training and immobilisation on human muscle fibres. Eur J Appl Physiol 4 3 : 2 5 - 3 4 MacDougall J, Sale D, Elder G, Sutton J (1982) Muscle ultrastructural characteristics of elite powerlifters and bodybuilders. Eur J Appl Physiol 48:117-126 Padykula H, Herman E (1955) The specificity of the histochemical method of adenosine triphosphatase. J Histochem Cytochem 3 : 170-195 Rusko H, Havu M, Karvinen E (1978) Aerobic performance in athletes. Eur J Appl Physiol 38:151-159 Salmons S, Vrbova G (1969) The influence of activity on some contractile characteristics of mammalian fast and slow muscles. J Physiol 201 : 535-549 Schantz P, Randall-Fox E, Norgren P, Typ6n A (1981) The relationship between the mean muscle fibre area and the muscle cross-sectional area of the thigh in subjects with large differences in thigh girth. Acta Physiol Scand 113:537-539 Schantz P, Randall-Fox E, Hutchinson W, Typ6n A, Astrand P-O (1983) Muscle fibre type distribution, muscle cross-sectional area and maximal voluntary strength in humans. Acta Physiol Scand 117:219-226 Spitler D, Diaz F, Horvath S, Wright J (1980) Body composition and maximal aerobic capacity of bodybuilders. J Sports Med 20:181-188 Sz6gy A, Cherebetiu C (1974) Minutentest auf dem Fahrradergometer zur Bestimmung der anaeroben Kapazitfit. Eur J Appl Physiol 33:171-176 Tesch P, Karlsson J (1978) Isometric strength performance and muscle fibre type distribution in man. Acta Physiol Scand 103 : 47-51 Tesch P, Larsson L (1982) Muscle hypertrophy in bodybuilders. Eur J Appl Physiol 49:301-306 Thorstensson A (1976) Muscle strength, fibre types and enzyme activities in man. Acta Physiol Scand [Suppl] 443 Viitasalo J, Komi PV (1978) Force-time characteristics and fiber composition in human leg extensor muscles. Eur J Appl Physiol 40:7-15 K. Hfikkinen et al.: Performance characteristics of elite power athletes Viitasalo J, Mfikinen P (1980) Comparison of five different methods for determination of muscle fibre areas. Presented at the Fifth Puijo Symposium 6 - 8 August 1980, Kuopio, Finland [Poster] Viitasalo J, Saukkonen S, Komi PV (1980) Reproducibility of measurements of selected neuromuscular performance variables in man. Electromyogr Clin Neurophysiol 20:487-501 Viitasalo J, Hfikkinen K, Komi PV (1981a) Isometric and dynamic force production and muscle fibre composition in man. J Human Mov Studies 7:199-209 105 Viitasalo JT, Aura O, Hfikkinen K, Komi PV, Nikula J (1981b) Untersuchung von Trainingswirkungen auf die Krafterzeugung und Sprungh6he. Leistungssport 11:278-281 Widerman P, Hogan R (1982) Body weight loss in a wrestler preparing for competition: a case report. Med Sci Sports Exerc 14 : 413-418 Accepted July 12, 1984