Backed By Science

Multiple scientific studies have proven that cooling the palms of the hands during resistance or aerobic exercise brings immense benefits. Click the “Research” tab for links to the scientific papers and reviews.

“Better Than Steroids”

Researchers at Stanford University showed that using palmar cooling for 6 weeks resulted in a 22% increase in one-rep maximums. That increase is greater than if the subjects were to use performance enhancing drugs (PEDs) for 6 weeks. It’s also equivalent to the increase they would have seen if they used anabolic steroids for 10 weeks. [1]

Person holding a JOLT palm cooling device with the slogan 'Recharge Your Workout' in a gym.

How Does Palm Cooling Work?

Your palms, as well as the bottoms of your feet, are the body’s natural heat sink. When you lift weights, run, or perform other physically demanding tasks, your muscles heat up causing them to fatigue. By cooling your palms, and thus your core body temperature, you can significantly reduce muscular fatigue. One study showed that a difference in core-body temperature of only 0.6° C results in a 17% increase in work volume. [1]

Open right hand with fingers spread apart, skin appears slightly reddish, isolated on white background.
A human hand with fingers spread apart, showing the palm appearing pale.

(Right) Surface of the palm appears pale after using Jolt Bar, meaning the body temperature has cooled down.

(Left) Surface of the palm appears red due to blood vessels at the surface releasing heat from exercise.

Multiple studies have shown an immediate increase in work load of roughly 17% when using palm cooling between sets of exercises. [1, 4] Imagine how this can transform you in the gym, in a big game, or wherever you put the work in.

Immediate Results

A person wearing a sleeveless gray shirt lifting a barbell at the gym, showing muscular arms.