The Hot Rock does its job well—as long as you’ve got an outlet handy.
When it comes to soothing sore muscles, I have two go-tos: heat, and massage. I’ve always had to enjoy those things separately, though. For a quick and easy "massage," a foam roller does the trick; and for heat, I use a heat pad or, on my way to and from the gym, the heated seats in my car. But now there’s a product that combines them, and it’s genius: the HotRock heated roller.
Technically it’s not a “foam” roller, because it’s not made of foam. It’s a hard plastic cylinder, hollow inside, that plugs into the wall. One end has a little screen (to display the temperature) and four buttons to turn it on and control it. The other end has a door, inside which you’ll find the attached power cord.
So, yes, you need a wall outlet to use this thing. (Sort of. More on that in a minute.) It’s the size of a pretty standard mini foam roller, a little under 13 inches long. The heated area, supplied by wires that wrap around it underneath the cover, is about the middle 6 inches of the roller. If you’re hoping to warm up a wide area, say your upper back, you’ll need to make multiple passes.
The outside of the roller is encased in faux leather (“marine-grade vinyl,” they call it) and it’s allegedly removable—although it seems to be a pretty tight fit. Dirt and debris wipe off, so you don’t need to remove the sleeve for cleaning.
HotRock sent me a roller to test. Following the manufacturer’s instructions, I opened the little door, pulled out the power cord, and plugged it into the wall. The HotRock came with a drawstring bag that’s supposed to hold heat in while it’s warming up, so I used that as instructed.
Here’s the basic procedure:
Plug the cord (found inside the little door) into a wall outlet.
Press the power button to turn on the LCD screen.
Select the temperature (between 125 and 175 degrees, in 10-degree increments).
If you want to use it for more than 30 minutes, press the timer button and use the up and down arrows to set the time (up to 180 minutes).
Optionally, slip the drawstring bag around it while it warms up.
When the roller is up to temperature, take it out of the bag. You can use it while it’s still plugged in.
The HotRock is advertised as heating to 175 degrees in just five minutes, but I found it took a bit longer—around eight minutes with the drawstring bag. (The company says that it will feel like it’s up to temperature a few minutes before the internal sensor reports the same number.)
If you want a lower temperature, it will get there more quickly. I found it got to 130 degrees in about three minutes.
The top setting of 175 was great for rolling my back through layers of clothes, but that was definitely too hot to be comfortable on bare skin. I found the lowest setting of 125 to be perfect to roll a bare leg.
There are other heated massage tools out there, like this microwaveable MojiHeat, but they don’t get as hot—MojiHeat gets up to 140 degrees for 30 minutes. If you want the higher settings or the longer time, the HotRock is a better option—but it’s nearly double the price, and you have to deal with the power cord.
You would think the cord would get twisted or tangled if you use the roller while it’s plugged in, but I didn’t find that to be a problem. Usually you’re rolling it back and forth in a small area, and the cord has enough room to move to withstand that just fine. The cord is also long enough that I didn't feel tethered to the wall; nine feet is plenty.
Conveniently, the roller is big enough on the inside that you don't have to wrap or fold the cord carefully. Just stuff it in, it'll be fine.
But since not every location has a wall outlet within nine feet, I wondered if it was possible to use the HotRock after unplugging it. I heated it up to 175, then put the cord away and started a stopwatch. The roller maintained a nice level of heat for several minutes, and around five minutes it was pleasantly warm but no longer anything I’d describe as “hot.” That would be enough for a quick warmup session, if you don’t have access to a wall outlet in the place where you do your foam rolling.
It’s really just another massage tool, so the benefits are “it feels good.” The evidence on massage for recovery and health is mixed; some sources find it helps recovery or aids in mobility. Most experts would say to use heat and/or massage if they feel good to you.
My only real complaint about this type of device is that when I’m in the mood for heat on a muscle (ahh, relaxing), I’m usually not in the mood to get on the floor and move around, maintaining appropriate pressure on the body part I’m rolling (so much work!). But I know that some of you love your foam rollers, so this might be a welcome addition.
The HotRock website has testimonials from athletes, and honestly the one I found most compelling was the Crossfit coach who gets to the gym before 5 in the morning, and it’s so cold in the winter. She turns on the building heat, makes herself a coffee, and does a rolling session with her heated foam roller. That sounds heavenly.
Combines heat and self-massage
Cord stows away easily in the center of the roller
Adjustable heat up to 175 degrees F
Auto-shutoff timer
No beep to let you know when it’s up to temperature
Need to be near an outlet to use it
Pricey compared to microwaveable rollers
Temperature settings: 135, 145, 155, 165, 175 degrees
Timer settings: 30, 60, 90, 120, 180 minutes
Length of roller: 12.75”
Diameter of roller: 5.5”
Length of power cord: 9 feet
