Differentiating physiological adaptation from cardiacpathology can prove challenging in athletes, as thenature and magnitude of cardiac remodelling inresponse to exercise are governed by several importantfactors. These factors include age, sex, anthropometry,ethnicity and sporting discipline.1One element not rou-tinely considered in the athlete’s heart continuum, is theimpact of repeated exposure to hot environmentalconditions.Several major sporting events take place in thesummer months, often in hot ambient conditions (e.g.2004 Athens, 2008 Beijing and 2016 Rio Olympics, 2015Beijing and 2019 Doha IAAF World Championships).The 2020 Tokyo Olympics are predicted to be the hot-test on record. Exercising in the heat induces thermo-regulatory and physiological strain,2which in turn leadto reductions in endurance exercise capacity.3Athleteswill accordingly train repeatedly in a hot environmentprior to a competition as a method to offset thesepotential performance impairments.4Most naturalacclimatisation (or artificial acclimation) protocolsrequire athletes to undertake daily exposure to theheat for up to 14 days, in an attempt to increasewhole-body (core and skin) temperature, induce sweat-ing and increase skin blood flow.5Heat acclimation,also induced by passive heating, elicits cardiovascularadaptations allowing for a lowered heart rate, anincreased stroke volume, a better sustained_Q, abetter defended blood pressure and an increased myo-cardial efficiency and compliance while exercising in theheat.6However, the repercussions of repeated heatexposure on cardiac structure remain unknown.Accordingly, we aimed to isolate the influence ofrepeated heat exposure on the myocardium, withoutthe confounding factor of exercise, by examining theimpact of 12 days of passive heat acclimation (PHA)on the resting cardiac structure and function of well-trained male athletes.
Wilson, M. G., Périard, J. D., Adamuz, C., Farooq, A., Watt, V., & Racinais, S. (2019). Does passive heat acclimation impact the athlete's heart continuum? European Journal of Preventive Cardiology, 1-3. https://doi.org/10.1177/2047487319836522