Hot Water Immersion Better than Cold to Maintain Exercise Performance

Different water temperatures aid different types of recovery

State College, Pa. (Nov. 21, 2024)-Soaking in a hot tub may be preferable to an icy cold bath after exercise if the goal is to maintain optimum performance, according to a new study. This is especially true for those competing in back-to-back races in a short time span. The research will be presented at the 2024 Integrative Physiology of Exercise conference, Nov. 20-22, in State College, Pennsylvania.

Cold water immersion aids recovery of exercise-induced muscle damage such as soreness and muscle fatigue, but it has not shown benefits for exercise endurance recovery. Hot water immersion has gained attention as a popular post-exercise trend that increases blood flow to the muscles. However, comparing the effects of both types of immersion on muscle damage and performance recovery has not been well studied.

In this latest research, scientists studied a group of young adult male recreational athletes on three occasions. Participants performed 50 minutes of high-intensity interval running and then soaked in a cold-water tub (59 degrees F), a hot-water tub (104 degrees F) or sat without immersing in water as a control condition. One hour after the workout, the research team measured the volunteers' jump height, and changes in creatine kinase and myoglobin (an enzyme and a protein, respectively, that can indicate muscle damage). The volunteers rated their level of muscle soreness.

Jump height from standing and squat positions were lower with cold water immersion than hot water. There were no significant differences in creatine kinase and myoglobin levels between the different water conditions. On the morning following each condition, the volunteers performed a running task at 90% exertion to determine their exercise capacity. No significant differences were observed between hot and cold water immersion conditions.

These results suggest that hot water immersion is preferable to cold water for promoting exercise performance. On the flip side, cold water immersion is more effective for alleviating inflammation, swelling and fatigue associated with exercise.

"While post-exercise [cold water immersion] is common on the sports field, cooling does not always have a positive effect on exercise capacity," said Mamoru Tsuyuki, first author of the study. "The novel findings from our study are that post-exercise hot water immersion promoted recovery of muscle power output compared to post-exercise cold water immersion. The findings will be useful for people who conduct multiple sessions of exercise or competition within a day."

NOTE TO JOURNALISTS: To schedule an interview with a member of the research team, please contact APS Media Relations or call 301.634.7314. Find more research highlights in our Newsroom.

Physiology is a broad area of scientific inquiry that focuses on how molecules, cells, tissues and organs function in health and disease. The American Physiological Society connects a global, multidisciplinary community of more than 10,000 biomedical scientists and educators as part of its mission to advance scientific discovery, understand life and improve health. The Society drives collaboration and spotlights scientific discoveries through its 16 scholarly journals and programming that support researchers and educators in their work.