Cortisol Predicts Performance During Competition: Preliminary Results of a Field Study with Elite Adolescent Taekwondo Athletes.

Competitive taekwondo composes a high stress situation leading to an increase in the stress hormone cortisol. Little is known about cortisol's relation to outcome (winning vs. losing) and performance in taekwondo. Therefore, the aim of the study was to investigate cortisol relation to outcome, performance and whether cortisol can predict performance during a competition. Twenty taekwondo combatants (13 males; M = 15) provided four salivary samples (C1: 30 min prior, C2: during, C3: after, and C4: 30 min after competition) during an international competition. Total points made in the two rounds during their first fight were used as a performance indicator. Results show no difference in cortisol between winners and losers, before or after competition. However, a negative correlation between performance and C1 as well as C4 was detected. Unexpected, a positive correlation between cortisol during the competition (C2) and performance was identified. A stepwise multiple regression analyses showed that C2 predicted 25.5% of the performance variance. Even if the sample size is relatively small due to the field experimental setting, some conclusions can be drawn to motivate future research. Potentially, in taekwondo it seems advantageous for performance to have higher levels of stress as indicated by cortisol during a competition, whereas particularly before the competition, sport psychological interventions should be provided to combatants to reduce their psychophysiological stress level.