Cool hands improve performance?

Bullshit DetectorLike most athletes and coaches, I am always looking for new competitive advantages. Moreover, I have an intense interest in thermoregulation as a limiter of performance. So when former podcast guest Dr. Tom Swensen passed along some press materials on the impact of hand cooling, no doubt to get me digging, I jumped on it. Some of you may recall the hand cooling devices Allen Lim used while at Garmin. Then, as now, I love the idea of simple tech that can aid recovery, but hand cooling? Back in 2008 I was just skimming and assuming that anything Lim used came with sound reasoning. After all, Dr. Lim is one of the leading applied exercise scientists in the world. However, Dr. Swensen’s message was a bit more eye popping, so I needed to delve into how and why hand cooling was enhancing recovery.

“Equal to or substantially better than steroids … and it’s not illegal.”

   After reading the article Swensen sent me, the mechanisms sounded intriguing and the results were astounding: increasing the number of continuous pull-ups from 180 to over 620 in just six weeks! As the author put it, “That was a rate of physical performance improvement that was just unprecedented.” The problem is it was an N of 1, a single dude in an uncontrolled experiment without any clear idea if his training changed either. So I looked closer and found a nice write up by Daniel Engberg in

In this article Engberg did his homework and found two studies by authors not connected to the inventors. Not surprisingly, the results were not so favorable. As Engberg points out, the inventors have performed their own studies with good results, but without matching the hand cooler against other cooling methods, including the highly vaunted ice vest, say, “…much of the work from Grahn and Heller’s lab has omitted any such comparisons.” In two different studies, one by the Air Force and the other performed at the University of New Mexico, the hand cooler failed to significantly impact performance. Here’s where it gets funny, though. The inventors from Stanford criticized the Air Force study for being too easy and the UNM study as being to intense. So apparently the hand cooler is a Goldilocks device, conditions need to be just right for it to work. Sorry, but I had to turn the alarm down on my Bullshit Detector!

I then went to Avacore’s website (this is the company cited by Lim in 2008) and looked at their peer-review (PR) research; more bullshit. Actually, in fairness, some was actually published in peer-review journals. However, minus the two that were truly PR, the rest were fraught with one or more of the following problems:

  • abstracts from conferences, where you can claim anything are not PR
  • “papers” (not unlike this blog post) published on the web are not PR
  • All of the favorable studies fail to control for the placebo effect
  • Similar to the last point, many studies lack a cooling comparison; the UNM study did find that while the hand cooler was ineffective, the cooling vest did significantly improve performance
  • research authored by one or more of the inventors is always favorable (I smell a little Conconi in the air)
  • While some of their science rationale is sound, they compare our hands to rabbit ears. The problem is that humans are the most copious sweaters on the planet, and that is one of our greatest physiological advantages.

I simply cannot find any convincing evidence to support the effectiveness of this hand cooling device. It would appear that the cost of this device far exceeds its benefit and the claim that its better than steroids is so grossly inaccurate that I needed to replace my Bullshit detector. While I cannot say definitively that my frozen Camel Bak is any better, considering I already own it, its worth using because placebo effects are real and can improve performance. Certainly, if I were running a Pro Tour level team, this seems a worthy investment to try, but I doubt Garmin paid $3000 per unit. Moreover, this unit simply is not worth that expense. However, don’t take my word on this. Below are some of the article links, and you can also go to Avacore and review their “peer-reviewed” research yourself. However, I think the inventors sum up their delusions of grandeur on this device best when one said:

“Anyone can show that something doesn’t work. That’s an easy thing to do.”

     Actually, the same thing can be said for the opposite, as well, which is what their research does.

Selling your soul

I continue to wonder if I would sell out on a product to make serious money. I would hope that any product I developed was not only based on science, but also on conscience. Perhaps someday, another blogger will be picking apart my own bullshit…unlikely.


Grahn et al. 2005 

Heller 2012

Walker et al. 2008 



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