Many athletes take ice baths after exercising, but that may not be the best way to add tone and muscle.
Research suggests that the practice may be counterproductive for those trying to build muscle
Athletes commonly use ice baths for post-workout recovery, but studies say the practice may impede muscle growth.
Studies have found that "[i]cing delays muscle regeneration following muscle injury in rats," increasing the risk of responding pathways inhibiting muscle growth. Studies on humans have also found that ice baths can impair muscle protein synthesis rates in recreational athletes.
A small study on 12 adult men found that placing muscles in cold water after exercise “blunted the postexercise increase in myofibrillar protein synthesis rate” and “also resulted in significantly lower daily myofibrillar protein synthesis rates.” In the study, the men exercised and then submerged both legs in water—one leg in thermoneutral water and the other in cold water—for 20 minutes. The men also drank a carbohydrate- and protein-packed beverage after exercising.
In the two weeks that followed, researchers collected biopsies of the men’s saliva, blood, and muscle to assess the impact of postexercise cooling on protein synthesis rates. They found that these rates substantially reduced over the two weeks, suggesting that “postexercise cooling negatively affects the skeletal muscle adaptive response to prolonged exercise training.”.
Another small study on nine adult men found that immersing muscles in cold water after exercise reduced muscle growth. On one day, the men were asked to complete a single-leg resistance exercise followed by sitting in cold water up to their waist for 10 minutes. On another day, they completed the exercise, followed by a 10-minute cool-down routine. Muscle biopsies were taken from the exercised leg before, 2 hours after, one day after, and two days after the tests to evaluate changes in genes and proteins associated with muscle growth.
"The present findings suggest that regular cold water immersion attenuates muscle hypertrophy independently of changes in factors that regulate myogenesis, proteolysis, and extracellular matrix remodeling in muscle after exercise,” the researchers concluded.
Ice bath risks versus benefits
For some, deciding whether or not to take a cold bath could mean weighing risks and benefits, some of which are uncertain.
“There may be minor benefits to cold-water exposure, but very little research has confirmed the advantages,” says Tracy Zaslow, MD, a primary care sports medicine specialist at Cedars-Sinai Kerlan-Jobe Institute in Los Angeles and a team physician for Angel City Football Club. “There are a lot of hypotheses, as opposed to data.”
Of the potential benefits, soothing muscles appears to be that with the most backing, Dr. Zaslow adds, though she says that “the popularity of cold-water exposure has outpaced research into the subject.”
A review of 20 studies on the muscular impact of cold water immersion found that the practice had “no effect on fatigue recovery.”
“The popularity of cold-water exposure has outpaced research into the subject,” Dr. Zaslow says. “You may or may not want to withstand the discomfort of a chilly dunk for uncertain rewards.”
What this means for you
Taking ice baths after working out could hinder muscle growth, according to studies. Despite the popularity of ice baths among the athletic community, doctors say that the practice might not be worth the hype.