Fact Checked

What Is a Treadmill Key?

Kelly Ferguson
Kelly Ferguson

A treadmill key is a safety feature that the vast majority of modern motorized treadmills employ. It works in a similar manner to the safety key on a jet ski or other machine where it is possible the user might fall off. The key itself allows the treadmill to operate and is on one end of a cord, the other end of which is attached to the user. Removal of the key indicates that there may have been an accident and triggers the treadmill's safety feature that stops the belt from moving further.

While different brands of treadmills require a specific size and shape of treadmill key, the basic function of the key is the same. Most treadmill keys clip onto the user's clothing, but some may have a bracelet at one end that can be worn around the wrist. The treadmill requires constant contact with the treadmill key to remain powered on, and if the key is removed, the treadmill will immediately stop moving and turn off to prevent injuring the user in case he or she has stumbled and fallen off of the belt.

Treadmill keys typically clip onto a runner's clothing or use a bracelet to attach to the wrist.
Treadmill keys typically clip onto a runner's clothing or use a bracelet to attach to the wrist.

The manner in which the treadmill key attaches to the treadmill can vary depending on the brand and model. Some are shaped like a small, thin card that is inserted into a slot on the treadmill, and when combined with the press of a "power" or "start" button, turn the treadmill on and allow the belt to move. Other brands and models use a magnetic treadmill key, which is easier to pull off of the magnetic pad on the treadmill's interface and may be more sensitive to movements, including accidental falls, that pull the cord to the side. This type is slightly less convenient for the user because it is easier to accidentally knock the magnet off of the pad, interrupting the workout, but it also keeps the user safer from injuries when falling to the side of the treadmill. These are also typically less likely to break and need replacement than the card type.

Unfortunately, many users do not feel that it is necessary to wear the treadmill key or feel that it is too inconvenient to tie around the wrist or clip onto a pocket or sleeve. If the user falls without wearing the treadmill key, there will be no signal to stop the treadmill's motor, and the belt will keep moving. This can be dangerous if a foot or other body part or piece of clothing has gotten caught under the belt or wedged under the machine. Also, tripping and falling when the belt is moving at high speeds can send the user shooting backward off the end of the machine into a wall or whatever is placed behind the treadmill.

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Discussion Comments


Those keys are lifesavers! Years ago, I went to this gym and one of the girls who worked there used Armor All on the treadmill surface, in an attempt to clean them. Of course, this made them slick as glass.

One woman was walking on a treadmill that they hadn't cleaned up yet, so it was still slick. She went off the back of that thing and fortunately, the key popped off the circle and the treadmill stopped. She twisted her ankle, but was otherwise OK. I think the girl lost her job, which was unfortunate, but putting Armor All on a treadmill was just boneheaded. Someone could have been seriously injured.


I generally use the treadmill key at the gym. I don't really want to end up flat on my back in front of the whole place. They can be kind of inconvenient if you're jogging, because you can accidentally knock it loose.

I usually clip the magnet to the bottom of my T-shirt. It doesn't get in the way nearly as much, and I'm still using good safety protocols. I'm not as apt to get tangled up in it, either.

My gym has plug ins so we can watch TV while we work out, and that's what I usually do. I have been known to get caught up in a program and zone out, which is when I'm most apt to need that kill switch.

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    • Treadmill keys typically clip onto a runner's clothing or use a bracelet to attach to the wrist.
      By: starush
      Treadmill keys typically clip onto a runner's clothing or use a bracelet to attach to the wrist.