INTRODUCTION: Expert shooting performance is preceded by an increase in frontal midline theta (FmTheta), suggesting an increase in the top-down working memory activation1, and by lower left temporal-frontal upper alpha coherence^2, suggesting lower engagement in conscious processing of explicit knowledge to control motor execution. The aim of the present pilot study was to assess the feasibility of processing EEG data recorded in conditions of high physical load, such as in biathlon. We expected shooting performance to be preceded by changes in FmTheta power and in left temporal-frontal upper alpha coherence. We further hypothesized the intense physical exercise to impair shooting performance and disrupt preparatory cortical activity. METHODS: 2 adolescent expert biathletes completed 12 blocks of 5 repeated shots under (i) a resting condition and (ii) an exercise condition (i.e. each shooting block was preceded by 3min on a cycle ergometer at 90% of maximum heart rate). 64 channel EEG was recorded using the ANT Neuro eegosport™ system. Shooting accuracy was measured through a computer controlled device and a sound threshold criterion allowed the identification of the timing of each shot. Theta power and cross-channel upper alpha coherence (short-time FFT, Welch's method) were computed over the last 3 seconds preceding each shot (3 intervals each lasting 1 second). The 10 best and 10 worst trials were clustered on the basis of shooting accuracy. RESULTS: A 2 Performance Outcome (best, worst) × 2 Condition (rest, exercise) ANOVA showed that shooting accuracy was impaired by physical exercise (p=.003). A 2 Performance Outcome × 2 Condition × 3 Time (-3 s to -2 s, -2 s to -1 s, -1 s to 0 s) ANOVA revealed that Fm? (Fz) power increased over time, with lower values following physical exercise in the last time bin (p=.005). Ttests demonstrated that best (vs. worst) shots were preceded by marginally higher FmTheta power in the last time bin (p=.073). A 2 Performance Outcome × 2 Condition × 3 Time ANOVA revealed that left temporal (T7) - frontal (Fz) upper alpha coherence was lower following physical exercise in the last time bin (p=.009). T-tests showed that best (vs. worst) shots were preceded by lower T7-Fz upper alpha coherence in the last time bin (p=.025). DISCUSSION: Consistently with previous findings the best shooting performance was preceded by higher FmTheta power and lower left temporal-frontal upper alpha coherence. Additionally, these findings imply a modulatory effect of physical exercise on the cortical activity preceding expert sport performance. In particular, it is suggested that performance following intense physical exercise is preceded by lower top-down working-memory activation and lower explicit processing. Following these preliminary results, a full study will be conducted with the aim of further clarifying the cortical activity pattern in preparation to rifle shooting following physical exercise on a larger cohort. --- The hosting University of Jyväskylä is planning to publish conference proceedings "Science and Nordic Skiing III". In case you are interested in this publication please contact the editors (Anni Hakkarainen anni.s.j.hakkarainen@jyu.fi) to become registered for the book.
© Copyright 2015 3rd International Congress on Science and Nordic Skiing - ICSNS 2015. 5-8 June 2015, Vuokatti, Finland. Veröffentlicht von University of Jyväskylä; University of Salzburg. Alle Rechte vorbehalten. / Übersetzt mit https://www.DeepL.com/Translator