A new small study suggests that hot water can help muscles repair themselves and become stronger.
Ice baths after exercise are hot, especially among influencers.
But a new small study suggests that recreational athletes perform better if they soak in a hot tub rather than a frigid one, especially if there are breaks in their workouts, such as halftime in football and soccer, according to a report presented Thursday at the 2024 Integrative Physiology of Exercise Conference in University Park, Pennsylvania.
When you exercise vigorously, muscle fibers are damaged and the hot water can increase blood flow, which helps the muscles repair themselves and become stronger, said the study’s lead author, Mamoru Tsuyuki, a master’s student in sports and health science at Ritsumeikan University in Shiga, Japan.
“Also increasing muscle temperature is going to help improve power output,” Tsuyuki told NBC News in a Zoom call. “When you need to perform twice in the same day, such as in sports that have a halftime, heat is better. During the 15 or 20 minutes, if you can immerse yourself in hot water, you can probably perform better in the second half.”
That doesn’t mean there’s no value in icy soaks, Tsuyuki said, adding that other studies have shown that the frigid water can relieve muscle soreness. Moreover, ice is best if there is an injury.
Tsuyuki said he’d like to see more research comparing the benefits and disadvantages of both temperature soaks.
“We used endurance running, but the results might be different with other types of exercise,” he added.
Why is a hot soak better?
To take a closer look at the impact of hot and icy soaks, Tsuyuki and his colleagues rounded up 10 young men to perform in a three-part study.
The men performed 50 minutes of high-intensity interval running and then soaked for 20 minutes in a 59-degree tub; a 104-degree tub; or sat without immersing themselves in water.
All 10 men experienced all three conditions during the study.
One hour after the initial workout, the study volunteers were asked to jump as high as they could from standing and squatting positions. The height the men attained when jumping was lower after a cold soak than a hot one.
There was no difference in muscle soreness whether the men soaked in cold or hot water.
