Heat stress training camps for endurance sport: a descriptive case study of successful monitoring in two ironman triathletes

A common practice amongst endurance athletes is to purposefully train in hot environments during a ‘heat stress camp’. However, combined exercise-heat stress poses threats to athlete wellbeing, and therefore heat stress training has the potential to induce maladaptation. This case study describes the monitoring strategies used in a successful three-week heat stress camp undertaken by two elite Ironman triathletes, namely resting heart rate variability, self-report wellbeing, and careful prescription of training based on previously collected physiological data. Despite the added heat stress, training volume very likely increased in both athletes, and training load very likely increased in one of the athletes, whilst resting HRV and self-report wellbeing were maintained. There was also some evidence of favourable metabolic changes during routine laboratory testing following the camp. We therefore recommend that practitioners working with endurance athletes embarking on a heat stress training camp consider using the simple strategies employed in the present case study to reduce the risk of maladaptation and non-functional overreaching.