One of the potential use cases for palm cooling is alleviating exercise intolerance.
For people who are overweight or are managing diseases such as Hashimoto’s, exercise can result in excessive overheating, rapid heart rate, and fatigue which creates significant barriers to reaching health goals.
While there has not been a lot of research on the impact of palm cooling on exercise intolerance, some preliminary research by Stacy T Sims, Sandra Tsai, and Marcia L Stefanick in 2012 showed that palm cooling significantly improved exercise tolerance among sedentary obese women.
The authors explained that adipose tissue (fat) acts as a thermal insulator making it difficult to dissipate heat. They hypothesized that by reducing this thermal discomfort during exercise, tolerance increases.
In their 12-week study, women who palm cooled saw significant improvements in aerobic capacity (faster 1.5 mile walk test and greater exercising heart rate), reduced waist circumference, and improved resting blood pressure.
These results are very promising!
Norrie & The Narwhals Take on Exercise Goals
We were very excited to hear from Norrie (my mom!) who recently bought a pair of Narwhals. She’s been incorporating palm cooling into her trainer-guided workouts for a couple of weeks.
Exercise has never come easy to Norrie. But she has been working out consistently with her trainer for the last two years. Still, increasing intensity remained challenging… until the Narwhals entered the scene!
“The difference is in the recovery. I normally would do the treadmill for 4 minutes, and then need to rest for 10 minutes. Now, I start to feel recovered 30 seconds into cooling and I can sustain repeated bouts of 4 minutes on, 2 minutes off.”
She has also been increasing resistance between weightlifting sets when she would normally stay at the same weight for all three sets.
Early days for sure, but this N of 1 story is promising. Go Norrie!
Why Would Palm Cooling Alleviate Exercise Intolerance?
It turns out that our palms are like radiators for the body. Below the skin in our palms are special structures called arterio-venous anastomoses (AVA).
AVAs are direct connections between arteries and veins which allow for increased blood flow, especially when we are exerting ourselves, and efficient heat transfer.
You can turbo charge this naturally occurring system by cooling your palms for two to three minutes in between resistance training and aerobic exercise sets.
A few parameters must be respected for this protocol to work.
Unfortunately, it’s not as simple as holding ice. If you hold something too cold, those AVAs will constrict and blood flow will be significantly reduced.
The ideal temperature for most people is 50-60°F (10-15°C).
You also need to hold onto something that has good thermal conductivity (i.e. copper) and a mechanism for whisking away heat.
Learn more about what makes a good palm cooling device (and how to DIY one).
For further reading, we recommend a couple of studies:
- This research looked at palm cooling and its impact on increasing training volume and strength gains.
- Perhaps even more relevant to the exercise tolerance application is a 2009 study that looked at how palm cooling helped heavily insulated people recover faster from intense aerobic work.
- Lastly, you can read the full poster session that inspired this post at Abstract MP016: Innovation in Exercise: Increasing Capacity of Sedentary Obese Women with Cooling