The relationship between physiological and performance variables during a hot/humid international rugby sevens tournament.

To characterise physiological responses to competing in an international rugby sevens tournament played in hot/humid conditions, core temperature (T) and T predictors were collected from 11 elite men's rugby sevens athletes competing in the Oceania sevens tournament in Suva, Fiji. T, body mass change, sweat electrolytes, playing minutes, total running distance, high speed running distance (HSD), psychrometric wet bulb temperature and exertional heat illness symptoms were collected pre, during and post games. Linear mixed-models were used to assess the effect of T predictors on post-game T, along with differences in T across measurement periods. Compared to baseline on both tournament days, mean T was higher during all between game (recovery) measures (all >1.30, <0.01). On both tournament days, eight athletes reached a post-game T >39.0°C, with several athletes reaching >39.0°C during warm-ups. Mean post-game T was related to playing minutes, total running distance, HSD, and post warm-up T (all  < 0.01). The T during warm-ups and games regularly exceeded those demonstrated to be detrimental to repeated sprint performance (> 39°C). Warm-up T represents the easiest predictor of post-game T to control via time/intensity modulation and the use of appropriate pre- and per-cooling strategies. Practitioners should be prepared to modulate warm-ups and other heat preparation strategies based on likely environmental conditions during hot/humid tournaments.