AGGRESSIVE BEHAVIOR Volume 13, pages 9-13

Testosterone and Cortisol Responses to Competitive Fighting in Human Males: A Pilot Study Alicia Salvador, Vicente Simon, Fernando Suay, and Luis Llorens

Departamento de Psicologia Fisiologica (A.S., KS., F.S.) and Laboratorio de Medicina Nuclear e lsotopos (L. L.), Hospital Clinic0 Universitario, Universitat de Valencia, Valencia, Spain

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Serum testosterone and cortisol levels were measured by radioimmunoassay in 14 young male judo competitors, in samples taken 10 minutes before and 45 minutes after two different procedures. The first involved physical exercise and the second competi- tive fighting. Both procedures were of 5 minutes duration and sessions took place at the same time (between 1O:OO A.M. and 12:OO P.M. local time) but on different days. Comparing the two situations over all subjects revealed that testosterone increased after exercise and decreased slightly after Competition. Between subject comparisons suggested that contrary to previous claims, winning or losing did not significantly change the testosterone and cortisol levels. Comparisons of subjects who were members of the Regional Team with individuals who were not part of that group confirmed that members increased their testosterone levels after competition, whereas the nonmem- bers showed a significant decrease. Moreover, success of the individuals, in their sporting record, correlated positively and significantly with the changes of testosterone observed during the competition. These preliminary results suggest that previous personal experience of success can influence the pattern of the psychoendocrine re- sponse to a contest situation.

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Key words: physical exercise, judo competition, victory, defeat

INTRODUCTION

Physiological responses to the experiences of victory and defeat include the modi- fication of circulating levels of some hormones. Clinically, sporting competitions have been seen as suitable situations to study hormonal responses to winning and losing. Mazur and Lamb [ 19801 found that the pattern in changes of testosterone was different in winners and losers of a tennis match. Winners generally showed increases and losers decreases in titers of this steroid and significant differences were evident 1 to 2 hours after the match. Elias [1981] found that subjects winning a wrestling match showed significantly greater increases than losers when he compared percentage changes between testosterone levels seen 10 minutes before and 10 minutes after the match. Winners also showed significantly greater increases in cortisol than losers. Received for publication July 1, 1986; accepted October 3, 1986.

Address reprint requests to Alicia Salvador, Departamento de Psicologia Fisiologica, Facultad de Psicologia, Blasco Ibaiiez, 21.46010 Valencia, Spain.

0 1987 Alan R. Liss, Inc.

10 Salvador et a1

However, sporting competitions and fighting encounters involve an important degree of physical exercise, whose influence was not controlled in these earlier studies. As both cortisol and testosterone levels are affected by physical activity [Sutton et al, 1973; Frey, 19821, it is important to control this factor to ascertain whether any observed hormonal variations are consequences of physical activity rather than competition. Moreover, research with nonhuman primates (squirrel mon- keys) has suggested that changes in plasma testosterone are influenced not only by specific situations of victory or defeat but also by more stable characteristics such as dominance-submission or status in a hierarchy [Coe and Levine, 19831. It therefore appeared of interest to study the influence in human males of the wider experience of victories and defeats as indicated by the individual's history of success (sporting record), in addition to the influence of factors linked to a specific situation. This study aimed to clarify the influences of physical exercise, specific victory or defeat situa- tions, and individual history of success on testosterone and cortisol changes.

MATERIALS AND METHODS

Fourteen male Spanish judo competitors aged 16 to 19 years (mean=17.43, SD=0.85) took part in the experiment. Their mean period of practicing this sport was 6.36 years (SD=3.13). Seven of the subjects belonged to the Regional Team (they won a Regional Championship in Valencia 1 month before our experiment). Subjects participated in two different 5-minute sessions: one of physical exercise and the other of competitive fighting. Both sessions took place between 1O:OO A . M . and 12:OO P . M . , local time, and the exercise session was performed just 1 week before the competitive encounter.

In the first session, subjects performed physical exercises that were intended to approximate the muscular effort involved in a competitive encounter. Subjects were matched according to body weight and membership in the Regional Team. Thus, members of each pair had similar body weights and, respectively, belonged/did not belong to the Regional Team (except the seventh pair). One subject (No. 14) did not perform the physical exercise session, but took part in the competition. The winners of each encounter received a small monetary reward (1,OOO pesetas). The sporting success history of each participant was assessed by a questionnaire in which infor- mation about participation in Regional, National, or International Championships and the positions obtained was requested. This information was converted into an index of success for each subject, being the algebraic sum of the values obtained according to the following scale: lst, 2nd, and 3rd positions in International competitions were worth 6, 5 , and 4 points, respectively; Ist, 2nd, and 3rd positions in National competitions were worth 5 , 4, and 3 points; and lst, 2nd, and 3rd positions in Regional competitions were worth 4, 3, and 2 points, respectively.

Blood samples were taken 10 minutes before and 45 minutes after competiton or exercise. Serum testosterone and cortisol levels were measured by radioimmunoassay (RIA). The method for testosterone (Immuchem testosterone I'25 Assay) detects the total unconjugated form of this steroid but does not distinguish true free testosterone from protein (albumin and SHBG) bound hormone. The intra-assay variation coeffi- cient was 2.66 and the inter-assay value was 4.02. Cortisol levels were determined using the Amerlex Cortisol RIA kit, where the intra-assay and inter-assay variation coefficients were 2.15 and 13.26, respectively. In order to eliminate the masking

Hormones in Competitive Fighting 11

TESTOSTERONE CORTISOL

-20 - 30 I -20 - 30 I IW PHYSICAL EXERCISE

H COMPETITION

Fig. 1. exercise or competitive bouts ( N = 13).

Mean percentage changes of testosterone and cortisd in male judo subjects given physical

effect of large individual differences, all comparisons between hormonal levels were carried out on percentage changes.

RESULTS The Influence of Activity and Competition on Testosterone and Cortisol Levels

Combining the data for all subjects (N = 13) showed increasing testosterone levels during the exercise session, and decreasing ones during the competitive session (Fig. I) . Differences between the percentage changes produced during the activity session (mean= 17.28, SD =40.74) and those produced in competitive session (mean= -4.97, SD =2 1.73) were close to significance (t = 1.85, p < 0.10, two-tailed). Cortisol levels did not show any relevant difference (t= -.47, n.s.) between the exercise (mean= 18.79, SD=92) and the competitive (mean=5.76, SD=53.79) situations.

The Influence of Competition on Testosterone and Cortisol Changes

The effects of victory or defeat upon the hormonal changes in the competitive situation were studied by comparing percentage testosterone and cortisol changes of winners and losers. One of the seven pairs who engaged in competitive encounters produced a draw; hence there were six winners and six losers. Differences in the testosterone changes between winners (mean= -5.01, SD =22.98) and losers (mean= -4.46, SD=24.57) were not significant (t= -.04, n.s.); the same was true of cortisol differences: mean= 18.7, SD=65.93; and mean= -5.72, SD=47.15 for winners and losers, respectively (t= .74, n.s.).

History of Success and Hormonal Variation in the Competitive Situation

Members of the Regional Team experienced a slight increase in testosterone level (mean=4.7, SD=23.59) after the fight, whereas nonmembers showed decreases (mean= - 16.39, SD=12.33), (t=2.09; p<O.O5, one-tailed; p<0.10, two-tailed) (Fig. 2). The differences between the two groups in the changes of cortisol levels

12 Salvador et a1

10

Percentage change 0

- 10

- 20

TESTOSTERONE

.

t = 2.096 (p Q 0.07)

Percentage change

- 10

- 20

- 30

CORTISOL

t = -1.63 (n.s.)

hU MEMBERS (N = 7) El NON-MEMBERS (N = 7)

Fig. 2. Mean percentage changes of testosterone and cortisol in members and nonmembers of the Regional Team.

were reversed with cortisol being decreased in Regional Team members (mean= -15.4, SD=25.62) but increased in nonmembers (mean=27, SD=63.89), (t= - 1.63; n.s.) (Fig. 2). Furthermore, the index of success showed a significant positive correlation coefficient (Pearson’s r value) with the testosterone percentage change (r= .52, p<O.O2). Cortisol, however, did not show a significant correlation with the index of success (r= - .38).

DISCUSSION

The finding that physical exercise provoked an increase in testosterone, whereas competition produced an overall decrease confirms and extends earlier findings. Increases of testosterone during exercise have also been reported by Sutton et al [I9731 and Vogel et a1 [1985], being attributed to (1) a decrease in hepatic flow Wahren et al, 19711 or (2) an increase in testosterone secretion produced by the elevation of circulating norepinephrine [Eik-Nes, 19641. These physiological varia- tions could explain the increases found during the exercise but not the decreases seen after competition. It is well known that stress (physical or psychological) produces decreases in serum testosterone. Therefore the decreases found in the competitive situation can be interpreted as a reaction to the stress experienced in this competition that outweighs the increases occasioned by exercise per se.

Hormones in Competitive Fighting 13

Members of the Regional Team presented increased testosterone levels, whereas nonmembers showed decreased testosterone levels after competition. This finding is reinforced by the significant correlation coefficient obtained between the index of success and testosterone percentage changes. These results suggest that hormonal responses to competitive situations are, in part, determined by the history of previous success. However, the present results do not confirm the recorded differences be- tween the hormonal responses of winners and losers found by Mazur and Lamb 1 19801 and Elias 1 1981 1. The lack of such significant differences in the present study may be related to the fact that no important prize or reward was at stake in the competition. The differences in timing of blood samples in these studies are also evident. As noted earlier, Elias 119811 took blood samples 10 minutes before and 10 minutes after the competition. Mazur and Lamb [I9801 obtained their samples 1 and 2 hours after the match. In the present experiment, blood was taken 10 minutes before and 45 minutes after the competition. Obviously, a more detailed study of the temporal course of these variations is required.

Members of the Regional Team showed a decrease in cortisol during Competition, whereas nonmembers showed an increase. These nonsignificant changes are consis- tent with changes in testosterone levels, since those hormones are generally inversely related.

In sum, this work must be considered a pilot study, but it supports the view that real but highly standardized sporting situations may be of value in studying the effects of physical and psychosocial stimuli on endocrine functions in humans. It also confirms that systematic analysis of the time course of hormone variations in a competitve situation is needed, and emphasizes that the effects of prior experience (including the history of success) can have a great influence on the recorded changes.

ACKNOWLEDGMENTS

This research was partially supported by Conselleria de Cultura, Educacion y Ciencia de la Generalitat Valenciana.

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Elias M (1981): Serum cortisol, testosterone and testosterone binding globulin responses to competitive fighting in human males. Aggres- sive Behavior 7:215-224.

Frey H (1982): The endocrine response to physical exercise. Scandinavian Journal of Social Med- icine, Supplement 1,29:71-75.

Mazur A, Lamb T (1980): Testosterone, status and mood in human males. Hormones and Behav- ior 14:236-246.

Sutton JR, Coleman MJ, Casey J, Lazarus L (1973): Androgen responses during physical exercise. British Medical Journal 1 :520-522.

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