Friday, July 20, 2012

Science Friday: Down with Ice Baths!

I hate ice baths. You come home from a hard workout, exhausted but glad to be done. But then it hits you, you're not done: the ice bath awaits. I bundle up and make a cup of steaming hot tea, but it doesn't help. Sitting among ice cubes is agony. 

An article in Running Times is one of many to question the ice bath recently. The theory behind ice baths is that the cold water forces blood out of your legs and back to your core, taking toxins and metabolic byproducts from your workout with it. When you get out of the ice bath, the blood comes rushing back to your legs, bringing oxygen and nutrients. This should help you recover faster and reduce soreness in the following days. But research is showing that the inflammation and body's natural responses to hard exercise may actually be good for you. They help to build back the muscles stronger, which was the point of your hard workout in the first place. Sitting among the cubes may make you feel temporarily better, but not necessarily make you stronger.

The Running Times article cites a study from 2005 looking at the difference between ice-bathed and un-bathed limbs. They had subjects either bike or use handgrips and afterwards submerged one limb in cold water (5 degrees Celsius = 41 Fahrenheit for the legs; 10 C = 50 F for the arms) and left the other limb at normal room temperature. One of the most surprisingly parts of this article was how the subjects reacted. In one study they had them submerge a leg for 20 minutes, take it out for 30 minutes, and then re-submerge it. The subjects called the first dip in close to freezing water as "close to comfortable" while the second was "moderately cold." I call ice baths many colorful words, but comfortable isn't one of them. (For most of the studies, subjects only did one ice bath.) They collected data three days before and three days after the exercise and ice bath. 

Across the board, the changes were modest. The authors stressed that they had purposely chosen an easier workout, one that would not induce muscle soreness. (Although athletes can't feel the toxins leaving or oxygen returning, most of what they can feel a day or two after an ice bath is the absence of soreness. Choosing a design that doesn't invoke soreness in the first place seems a little strange to me. I'll spare you the details, but another paper specifically examined the effect of ice baths on soreness and found no difference between cold and tepid water.) Because the workouts weren't intense, the differences between pre and post measures were small. The most intriguing comparisons were between the ice-bathed and control limbs. They found endurance and VO2 max to be higher in the control limbs compared to the ice-bathed limbs. Furthermore, arterial diameter was increased (suggesting increased blood flow to muscles) after training, but only in the control limbs. The authors go on to mention a host of responses the body has to exercise and how these responses (increased numbers of certain cell types, metabolites, and proteins) may not be as harmful as we once thought. They may be actually contributing to improved performance. Ice baths, rather than helping, would prevent these improvements. (This study doesn't actually look at any of these changes in the blood, which would have been interesting.)  

The Running Times article includes insight from big name coaches (Steve Magness, who just recently left his assistant position under Alberto Salazar, and Brad Hudson) and athletes (Ryan Hall and Hendrick Ramaala.) Magness says that the recent research has led the Oregon Project to stop using ice baths so frequently. (He notes that ice baths can still be helpful during an intense racing schedule, when it is more important to be ready for the next round then to make training improvements.) Ryan Hall, claiming ice baths are "not a fun part of the job," has also stopped using them. The article does note that Molly Huddle still uses them and says she feels better afterwards, acknowledging that it doesn't matter if it's just a psychological effect.

Using my WWKD theory (Kara used to work with Magness), this means I'm free to skip the ice baths!

Dream big and leave the ice in the freezer, 

1 comment :

  1. Congrats on the new PR in 5K! Keep at it!

    (Was "I'll show what I can do with no ice baths" part of the motivation?)