Scientific Programme
Physiology & Nutrition
IS-PN06 - Hormones, Heat, and Human Performance: Translating Mechanisms Across Models
Date: 09.07.2026, Time: 14:00 - 15:15, Session Room: Auditorium C (STCC)
Description
As extreme heat events and female participation in high-level sport increase globally, understanding hormonal modulation of heat tolerance is essential for athlete safety and performance. This symposium explores how hormonal regulation influences physiological responses to heat stress and exercise performance across experimental models. It integrates molecular, integrative, and applied perspectives to understand how endocrine and thermoregulatory systems interact during acute and chronic heat exposure. By linking preclinical and human studies, the session identifies mechanistic pathways explaining individual variability in heat tolerance, recovery, and performance. Dr. Orlando Laitano (USA) will present preclinical evidence, highlighting molecular and cellular adaptations to severe heat stress under varying hormonal states. Dr. Daniel Gagnon (Canada) will follow with acute human data, illustrating how biological sex modulates temperature regulation during exercise heat stress. Dr. Jessica Mee (UK) will conclude with chronic adaptation studies, discussing how biological sex and ovarian hormones modulate thermoregulatory adaptation. Unlike previous ECSS symposia on heat stress, this session provides a uniquely integrated mechanistic-to-applied perspective focused specifically on endocrine modulation across preclinical and human models, with dedicated emphasis on female physiology—a topic of growing scientific and societal relevance.
Chair(s)
Orlando Laitano
University of Florida, Applied Physiology and Kinesiology
United States
Speaker A
Orlando Laitano
University of Florida, Applied Physiology and Kinesiology
United States
Read CVECSS Rimini 2025: IS-PN06
When Hormones Meet Heat: Preclinical Mechanisms Shaping Exertional Heat Illness
Exertional heat illness (EHI) affects women at specific hormonal states, yet the mechanisms through which female reproductive physiology modulates vulnerability remain incompletely defined. This presentation synthesizes molecular and cellular evidence from preclinical models to demonstrate how fluctuations across the estrous cycle, as well as targeted hormonal delivery, alter thermoregulatory stability, microvascular integrity, and organ damage in response to severe heat stress. Particular emphasis is placed on hormonal-dependent modulation of endothelial barrier function (e.g., glycocalyx). By integrating these data, the talk highlights how hormonal milieu shapes susceptibility to EHI, influences survival, and modifies recovery trajectories. This talk will demonstrate that at core temperatures achievable only in preclinical models, hormones exert a profound modulatory influence on heat-induced injury, in stark contrast to the modest effects reported under the milder thermal loads used in human studies. The implications for resilience, heat acclimatization, and individualized risk stratification in female populations are discussed, emphasizing the need for sex-specific mechanistic frameworks in thermal physiology.
Speaker B
Daniel Gagnon
Université de Montréal, Montreal Heart Institute
Canada
Read CVECSS Rimini 2025: IS-PN06
Time for the sex talk: Does female sex and reproductive hormone status really affect temperature regulation or performance during exercise in the heat?
Biological sex and variations in reproductive hormone concentrations have long been considered important modulators of temperature regulation during exercise heat stress. Early studies demonstrated that female participants may experience a greater core temperature and sweat less during exercise in the heat relative to males. Studies also established that the mid-luteal phase of the menstrual cycle or the active phase of oral contraceptive use are associated with a higher basal core temperature that persists during subsequent exercise heat stress. These observations led to the pervasive notion that females are “less efficient thermoregulators” or that the menstrual cycle impairs exercise performance in the heat. Contemporary studies have challenged this notion by showing that: a) any effect of female sex on temperature regulation during exercise in the heat is small and of uncertain significance, and; b) variations in basal core temperature throughout the menstrual cycle or oral contraceptive use have little impact on performance in the heat. The talk will provide key reflections on how to study the effect of biological sex or reproductive hormone status on temperature regulation during exercise heat stress. The key message will be that female sex and reproductive hormone status have little influence on temperature regulation and performance during exercise in the heat. These reflections and the key message will be relevant to researchers in sports science currently studying or considering to study how females perform during exercise in the heat, as well as to any practitioners in attendance involved in the preparation of female athletes for competitions in hot environments.
Speaker C
Jessica Mee
University of Worcester, School of Sport and Exercise Science
United Kingdom
Read CVECSS Rimini 2025: IS-PN06
Adapting to the Heat: Does Sex or Hormone Status Matter?
Ovarian hormones modulate peripheral and central thermoeffector thresholds, potentially shifting the thermal load required to elicit robust adaptations. Chronic heat alleviation strategies aim to induce heat adaptation (HA) through structured exposure to hot environments, either via natural acclimatisation or heat acclimation in controlled settings such as heat chambers. HA elicits physiological adaptations that improve tolerance to heat stress, including lower resting core temperature, earlier onset of sweating and vasodilation, and increased sweat rate. However, interpretation in female participants is complicated by ovarian hormone fluctuations. Despite clear sex differences in thermoregulatory responses, females remain under-represented in HA research, limiting mechanistic understanding. Available evidence suggests females often require greater or prolonged thermal stimuli to achieve the same adaptations as males, and strategies developed in male cohorts may not reduce physiological strain in females. Menstrual cycle phase and hormonal contraceptive use can further influence adaptation. In this talk, Jessica will share mechanistic evidence on female-specific adaptation, highlighting hormonal modulation, cardiovascular and thermoeffector adjustments, and protocol-dependent responses. Attendees will gain insight into the influence of ovarian hormones on heat adaptation and the importance of designing individualised, evidence-based HA strategies for females.