Professional athletes routinely use 'cold water immersion' after sporting events.
It is said that dipping into icy water (usually 10 C) for five to ten minutes can improve muscle recovery and future sports performance. But what science is behind this claim?
Five experts in exercise physiology were asked to answer the following question: Does ice bathing after exercising improve performance? Here's what they had to say.
What happens to your muscles when you get cold?
People often use ice packs and frozen peas to reduce swelling after pulling a muscle.
Johanna Lanner is a specialist in muscle physiology at the Karolinska Institute, Sweden. She explains how it works.
"Cooling i reduces nerve impulse transmission, thus reducing the level of pain perception. ii) Induces constriction blood vessels in peripheral tissues (e.g. muscle), which may result in decreased fluid diffusion that may help in reducing exercise-induced acuteinflammatory response.
Llion Roberts is an Australian expert in exercise physiology and is a Griffith University graduate. He says that cold water immersion can also help to restore heart rate variability. This is the variation in the time intervals between heart beats.
Ice baths can have a positive effect on our brains and muscles. James Broatch, a Victoria University expert in exercise physiology, conducted a study that compared the effects of an ice-bath with a placebo. Participants were tricked into believing that an ice-bath was as effective as an actual ice bath.
Participants in the placebo condition were given a warm bath with what they believed was a special "recovery oil", but it was really a skin cleanser.
Broatch states that participants in both the placebo and ice bath conditions rated the benefits of the assigned recovery condition similarly, which translated into a similar recovery in leg extension strength over a 48 hour period after exercise.
Ice baths and muscle recovery after exercise: What are the effects?
According to Lanner, ice baths can be effective in "reducing exercise-induced delayedonset muscle soreness" (i.e., the pain and stiffness felt in muscles for several hours to days after strenuous or unaccustomed exercise).
Ice baths are often used to recover muscles after sporting events.
How do ice baths affect exercise performance?
Ice baths can help muscle recovery, which could lead to improved sports performance. It isn't as simple as that. Hakan Westerblad, a specialist in cell muscle physiology at the Karolinska Institute, Sweden, states "scientific studies have varying outcomes regarding post-exercise effects on subsequent performance with results ranging between minor positive effects to no effects to severe negative effects."
The problem with measuring the impact of ice baths upon exercise performance is the fact that there are so many types of exercise to choose from, like endurance and strength training.
Roberts states that "somewhat surprisingly, after strength training, cold water immersion might in fact hinder the benefits exercise".
His colleagues and he "found significant reductions or blunting of desired results from strength-training such as increasing strength, muscle mass, and cell improvements within the muscles." It was most likely due to the negative effects of cold water on the natural protein and cellular reactions that occur in the muscle after every strength session.
The effects of endurance training could be very different. Christopher Mawhinney is a specialist in sports science at Mahidol University, Thailand. He says that there is evidence suggesting that cooling exercised muscles increases the cellular signal that turns on mitochondrial Biogenesis.
When cells produce more mitochondria, they are called mitochondrial biology. These structures release energy and increase the number of mitochondria in their cells. The positive effects of endurance training include mitochondrial biogenesis, which could be amplified by ice baths.
The type of exercise involved will have a different effect on the effects of ice baths.
Rogers states that cold water immersion should not be used after strength training. It is best to avoid it after extreme sports or endurance exercises.
Ice baths are not recommended for strength training. However, they can be helpful for endurance exercises.
This article is based on five expert responses to the question: Does post-exercise ice swimming improve performance?
This expert response was published by Metafact.io, an independent fact-checking platform. Subscribe to their weekly newsletter.