In my last column, I highlighted a study published in 2015 in The Journal of Physiology that examined the impacts of post-exercise cold water immersion on long-term adaptations to muscle with strength training. For those who didn’t read that column, the study had twenty-one physically active men train two days per week for twelve weeks followed immediately by either ten minutes of cold water immersion (similar to an ice bath) or ten minutes of active recovery which consisted of low-intensity biking.
Surprising to some, the authors found that the cold water immersion group made significantly less progress in strength gains and muscle mass compared to the active recovery group. Further, the study authors also took blood samples and muscle tissue samples. They found that the presence of various molecules and compounds that help signal muscle growth were blunted in the cold water immersion group compared to the active recovery group.
So, it is possible that icing after a workout may not be the best method for recovery. But this study was focused solely on strength training. What about the impacts of icing on inflammation? What about the impacts on other types of training? For those questions, let’s examine a few more studies.
Another study published in The Journal of Physiology in 2017 examined the age-old assumption that icing after a workout decreases inflammation. This study included nine physically active men who performed one-legged lower-body resistance exercise on separate days, at least one week apart. After the first day, the participants underwent cold water immersion for ten minutes and on the other day, they performed the same low intensity cycling of ten minutes as in the other study. After each day, the authors collected samples of muscle from the subjects before, two, twenty-four, and forty-eight hours after exercise.
Exercise, as expected, increased various markers of inflammation. Remember that inflammation is the mechanism by which your body heals. This includes healing after a cut as well as healing and repairing your muscles to become stronger after a workout. After the training, there was no significant difference between cold water immersion and active recovery in the reduction of inflammation in muscle after exercise. It’s worth noting that inflammation did decrease in both conditions, but it did not decrease significantly better in the cold water immersion group than the active recovery group.
So then, does this mean we shouldn’t use ice for recovery at all since it didn’t decrease inflammation more than active recovery and may inhibit muscle and strength gains? Not exactly. So far, we’ve only covered the response of strength and muscle mass gains following strength training, such as lifting weights. We haven’t discussed other forms of exercise, such as endurance training.
Endurance training is a type of training that is sustained for longer periods of time, such as running, biking, playing soccer, using the elliptical, etc… Just because the use of cold therapy after strength training may not be our best bet for recovery from that exercise, it does not immediately rule out the use of cold therapy for endurance training or for other purposes.
In 2016, an article published in the journal Sports Medicine examined the impact of cold water immersion on blood and muscle markers that may be influential in recovery and adaptations to endurance exercise. The study found a positive impact of post-exercise cold therapy on these markers and positive impacts on cardiovascular recovery following exercise. However, viewing benefits on markers that may be beneficial to recovery from endurance exercise is not enough to draw conclusions on how actual recovery and performance are impacted. So it may be that icing improves recovery from endurance exercise but currently there is just not enough evidence to justify that conclusion.
So what does this mean for icing after exercise? Well, at best, it is conflicting for recovery after strength training but at worst, it may actually keep you from getting stronger and gaining more muscle. It could also positively impact recovery from endurance exercise but we simply don’t have enough evidence to make that conclusion yet.
However, we haven’t hit on a key benefit of icing that is well supported in the scientific literature: ice helps to decrease soreness after training and improve pain. This can help weekend warriors and those with chronic aches and pains to continue staying active. This is a key point to keep in mind with the practical application of icing for recovery. In my next column, I’ll wrap up the series by examining this thought in more detail.
Nick McClary earned his doctor of physical therapy from the University of Tennessee. He also holds a masters in business administration. He is a native of Georgetown County, lives in Pawleys Island, and works in Georgetown. Send him your health and fitness questions at: nmcclaryDPT@gmail.com.