5°C [25]. Heat stroke is defined as a condition in which body temperature is elevated to a level that causes damage to body tissues, giving rise to a characteristic clinical and pathological syndrome that affects multiple organs [29]. Distinguishing features of heat stroke are marked core body temperature

elevations greater than 40.5°C, failing sweating mechanisms, often complete cessation of sweating, and moderate to severe mental status impairment. It is a medical emergency in which total thermoregulatory failure will not reverse without external cooling measures and the mortality rates may exceed 10% [25]. 3.2 Exercise-dependent dehydration-induced ischemia Blood flow to central tissues (gut and liver) is reduced during exercise by

almost 80%, at 70% of VO2max [7]. Such decreased splanchnic blood flow and oxygen supply may induce changes in nutrient absorption, motility Small molecule library purchase and the mucosal integrity of the GI tract, resulting in GI complaints [30]. GI distress has been reported to be common among 30%-50% of endurance athletes, especially during marathons, triathlons and other endurance events. The symptoms seem to occur more often during competition in a warm environment [30] in the presence of systemic dehydration and lower plasma volume [8]. Long-lasting high-dose creatine supplementation (80 g/day during four months) is reported to lead to acute renal failure when associated with exhausting strength exercises and related lower plasma volume [31]. However, few or no adverse effects are observed when INCB024360 taking the recommended dose of creatine (10 g/day) [32, 33]. 3.2.1 Exercise-induced gastric emptying delay Gastric emptying (GE) is thought to be negatively affected as exercise intensities reach over 70% VO2max [34]. The presence of dehydration in strenuous exercise in cyclists was shown to induce significantly increased nausea, epigastric cramps and delay in gastric emptying. Gastric emptying

(GE) was significantly associated with increase in exercise-induced nausea. Exercise by itself led to next significant increase in plasma vasopressin and rectal temperature and significant decrease in plasma volume, irrespective of the dehydration state, but vasopressin concentration was significantly higher in dehydrated athletes. By adding dehydration to strenuous cycling, there was a delayed gastric emptying, but no differences in orocecal transit time, intestinal permeability or glucose uptake [30]. In an endurance running experiment, GI complaints were reported only with the dehydration exercise combination without any GI disturbances being reported by athletes in either exercise or dehydration test alone. Dehydration-exercise resulted in slower GE than in other two treatments with the effects of dehydration and exercise being additives in delayed GE.