NEW YORK (Reuters Health) - The pain of a short soak in ice water is supposed to cure the longer-lasting discomfort of sore muscles, but researchers say it may not make enough difference to be worthwhile.
Compared to their peers who soaked in warmer water or didn't soak at all, amateur athletes recruited from the University of Ulster in Northern Ireland reported a 2-point difference on a 10-point muscle pain scale after repeated soaks in 6°C (43°F) water.
That 20 percent reduction in pain - from around 3 points to around 1 - might have an impact on elite athletes who strive for the slightest incremental improvements in performance, said lead study author Chris Bleakley, but perhaps not for amateur exercisers.
"If they are not playing at a high level, then I let them know it's not going to make a huge impact," said Bleakley, a researcher and physical therapist at Ulster Sports Academy, where the study took place.
The idea that soaking in ice water can hasten the recovery of muscles made sore by a heavy workout is popular, especially in the sports world. But how much difference it makes, as well as the safety of repeated cold soaks, are still debated (see Reuters Health article of February 12, 2012 here: reut.rs/LYmX3b).
For the study, 50 students ranging in age from 18 to 35 years old induced sore muscles by using the heaviest weight possible on a standing hamstring curl machine. They did this for five days in a row, and on the first three days a treatment was administered after the exercise session.
The participants were divided into five groups, four of which got variations on cold-water soaking therapy, and the fifth just had a seated rest period after their workout.
One of the therapy groups did hot/cold soaks, with a minute in 100°F water, followed by a minute in 50°F water. The second group did a cold/air soak, with a minute in 50°F water, followed by a minute outside the tub. A third group soaked their legs for 10 minutes in 50°F water, and a fourth group did the same in 43°F water.
The researchers wanted to know which time and temperature dosages worked best. But Bleakley and his team didn't find any significant differences among all the groups in athletes' before and after scores for range of motion and muscle strength.
Only the group that had the 10-minute, 43°F soak reported noticeably less muscle soreness compared to the seated rest group.
Pain in all groups peaked 48 hours after the first workout session, but on that day the seated-rest group rated their soreness, on average, at 3.39 on the scale of 10 while the group that soaked 10 minutes at 43°F rated their pain at 1.35 out of 10. The other groups' pain ratings ranged between 2.77 and 3.4.
Determining how to effectively apply cold water immersion therapy "is certainly a basic question that needs to be answered in our field," said exercise physiologist Gillian White.
White, a doctoral student at The University of Toronto in Canada, was not involved in the study.
"My experience with cold water immersion is that athletes like it," she told Reuters Health.
Writing in the journal Physical Therapy in Sports, Bleakley and his team point to past studies for explanations of why ice soaks might soothe sore muscles. For example, ice water might reduce muscle inflammation, stimulate blood flow, make muscles feel less fatigued or it just might bring temporary relief by numbing the area.
Based on this study, "we still don't know really how cold water immersion might be working, or if it is," White said.
"But before anyone worries about which soreness approach they should use, they need to make sure they are getting enough sleep at night, eating good food during the day and sticking to a sensible training schedule," Bleakley said.
As an alternative muscle soreness treatment, Bleakley said compression skins might work.
"It's important to recognize there is not one cure-all," Bleakey said. "Athlete preference is important and most recovery methods require a holistic approach."
Massage therapy continues to be a good option for all levels of athletes looking to ease muscle soreness, White said. She pointed out that past studies have found strong links between massage and muscle soreness relief.
"Fluid build-up happens in the muscles, which is part of the reason muscles feel sore," White said.
"Massage helps move that fluid out of the muscles and back into the bloodstream," she said.
"I think a lot a lot of athletes already know that massage works," she added.
SOURCE: bit.ly/NCW0Ef Physical Therapy in Sports, online January 29, 2014.