Tsukuba, Japan—Endurance exercise in hot conditions leads to a progressive increase in core temperature, thereby increasing the risk of hyperthermia. Hyperthermia triggers excessive respiration (hyperventilation) and cerebral hypoperfusion, both of which can impair exercise performance or even contribute to heat stroke.
Researchers at the University of Tsukuba investigated the effects of pre-exercise ice slurry ingestion compared with the ingestion of the same beverage at 37°C. The study involved young male participants performing endurance exercises in the heat. Results indicated that ice slurry consumption lowered the core temperature during exercise, reduced ventilation (measured as the total lung air exchange), and increased the cerebral blood flow index.
However, participants who reported severe gastrointestinal distress (e.g., stomachache and diarrhea) did not experience reductions in ventilation or increases in cerebral blood flow index. Notably, excluding these individuals, ice slurry ingestion significantly improved late-stage endurance performance. These findings indicate that pre-exercise ice slurry ingestion alleviates hyperventilation and cerebral hypoperfusion when exercising in hot environments and may enhance endurance performance. However, its ergogenic effects may be diminished in individuals who experience gastrointestinal discomfort.
This study provides valuable insights into effective strategies for mitigating hyperventilation and cerebral hypoperfusion during exercise in the heat. These findings may facilitate the development of approaches to prevent performance impairments and reduce the risk of heat stroke under heat stress conditions.
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This study was supported by Ministry of Education, Culture, Sports, Science and Technology in Japan (grant number: 22H00499).
Title of original paper:
Ice slurry mitigates hyperventilation and cerebral hypoperfusion, and may enhance endurance performance in the heat
Journal:
Medicine & Science in Sports & Exercise
DOI:
10.1249/MSS.0000000000003662
Associate Professor FUJII, Naoto
Institute of Health and Sport Sciences, University of Tsukuba
Institute of Health and Sport Sciences
Medicine & Science in Sports & Exercise
3-Feb-2025