The impact of fatigue and different environmental conditions on heart rate responses and shooting accuracy during laser run event in elite modern pentathletes.

Abstract

Background: The final event in modern pentathlon, the laser run, determines the final ranking, and it is not known whether the athletes' heart rates (HRs) and success rates during the shooting in the laser run are affected by environmental conditions. Although heart rate (HR) affects shooting performance, exercise-induced muscle fatigue accompanying increased HR can affect shooting speed and accuracy. The aims of this research were (a) to compare the HRs of pentathletes before and after fatigue, (b) to compare the shooting performance of pentathletes in the field vs. laboratory environment, and (c) to compare the HRs of pentathletes during successful and unsuccessful shootings.

Methods: The HRs and shooting performances of the seven national team pentathletes were measured in two separate sessions under laboratory conditions (pre- and post-fatigue) and in the field (laser run event). Bruce protocol was used to create exercise-induced fatigue and the internal loads of the pentathletes were determined with the 10-point Borg scale. The first session consisted of pre- and post-fatigue shooting in the laboratory environment, and the second session consisted of shooting in the laser run event in the field environment. The pentathletes' HRs were monitored in all sessions.

Results: The shooting accuracy of pentathletes in the laboratory is not affected by fatigue, although the HRs before and after the fatigue protocol differ significantly (p < .001). The unsuccessful shot count in the field was not significantly different between laps, and the HR decreased significantly towards the last successful shot in each lap (p < .001). Although shooting accuracy was not significantly different between the field and laboratory, the HRs in the field were significantly higher than those in the scenarios performed in the laboratory (p < .05).

Conclusion: The findings revealed that HR was significantly affected by different environmental conditions and fatigue, but this was not accompanied by shooting accuracy, and significantly higher HR was achieved in unsuccessful shots compared to successful shots. We recommend that pentathletes perform running-shooting training in different weather and field conditions before the competition to adapt to different environments, especially during the competition seasons, instead of shooting in a polygon or laboratory.