Sex differences in cardiovascular demands of refereeing during international basketball competition

OBJECTIVES: The aim of this study was to investigate the impact of sex on cardiovascular responses of referees during elite international basketball competition. METHODS: Twenty-seven elite referees (9 female; 18 male) officiated a random sample of 18 matches during the final round of the 2013 Women's Eurobasket Championship. Continuous recordings of referees' heart rate (HR) during matches were obtained and analyzed for average HR, relative exercise intensity (% maximum HR, HRmax) and proportion of time spent within different exercise-intensity categories. RESULTS: During the championship, the average match HR was >150 bpm and approximated an exercise intensity of >85% HRmax for referees. Female referees exhibited lower average match HR (156.8 ± 10.2 vs. 163.6 ± 11.6 bpm, p<0.05) and exercise intensity (86.2 ± 5.5 vs. 89.5 ± 6.0% HRmax, p<0.05) compared to male referees. Referees spent most (>70%) of each match at a HR intensity of 70-89% HRmax with females experiencing more match time within the 55-69% HRmax category compared to males. Average HR and exercise intensity was greatest for all referees during the early part of the match (Quarter 1) that declined over the match. CONCLUSION: This study has demonstrated that sex significantly influences cardiovascular responses for elite basketball referees with lower responses for females potentially reflective of different movement patterns. Reductions in cardiovascular response noted during matches for all referees may reflect alterations in metabolism, match activities or induction of fatigue that should be considered in the development and training of elite referees for optimal match performance.