Are Under-Desk Treadmills Safe?

During their evaluation, our testers look at several different features of treadmills (including under-desk treadmills) that have an impact on safety—some that are directly reflected in the safety score, with others that show up in other parts of the assessment.

Safety keys: First, they check to make sure a machine has a safety key, a device that can be attached to the person walking on the belt as well as to the treadmill itself. This key will make the machine come to a stop if the key is pulled loose—in theory because a person has fallen. We also look at how quickly the safety key works. Ideally, the belt should slow down quickly but steadily when the key is pulled. Some of the under-desk treadmills that we tested do have emergency safety keys, but in many cases, pulling them causes the belt to slam to a sudden stop, which could cause a user to lose their balance if it’s pulled accidentally.

Inadequate handrails: Since under-desk treadmills are meant to be used under a workspace, it’s not a surprise that most don’t have handrails. Three of the machines we tested did have optional handrails that a user could fold up, but these were often too short to be practical and also seemed fairly flimsy. An absent handrail, one that’s too short, or a flimsy one could present a fall risk, especially if one of the latter two options instills a false sense of security. 

Speed problems: There were also issues with speed on the machines we tested. Even though under-desk treadmills are designed for walking and are not safe for running due to the lack of handrails and small size, some ran at higher speeds than our testers say are safe for walking. Plus, in some cases, the machines ran at speeds that didn’t match the displayed speed.

Narrow belts: Our testers factor the size of a treadmill’s belt into the ergonomics score (not the safety score), since belt size can limit who can comfortably use a treadmill. But the belts on most under-desk treadmills we tested were so narrow that it could be easy for someone to stray off the belt, especially if they were distracted by work while walking. With the exception of our top pick, which has a 19.5-inch-wide belt, these devices had belt widths between 14 and 16.5 inches (16 is very narrow in our standard scoring for treadmills). These narrow belts are often paired with narrow foot rails, and one device even had tilted foot rails, which could lead to someone rolling an ankle while trying to stand.

Most of the full-sized treadmills in our ratings are made by manufacturers who focus primarily on exercise equipment and have a long history of making treadmills. That’s not the case for many of these under-desk treadmills. Seven of the nine machines we tested are sold by companies that don’t appear to have much or any experience with treadmill manufacturing, and many appear to be small companies that aren’t easy to get in touch with in case there are issues with their product.

When you search for under-desk treadmills online, it’s not hard to find user-reported issues with poor customer service or machines that have been faulty. For example, the U.S. Consumer Product Safety Commission has one incident report from a person who said he experienced a head injury after the under-desk treadmill he purchased from Amazon suddenly stopped, throwing him into a desk. After that person received two defective replacements, Amazon removed the listing, but the same treadmill appeared again on Amazon under a different listing, according to the report.

Some of these under-desk treadmills are likely products that are purchased in bulk and then sold under different brand names, according to our testers. In one case, a machine we purchased arrived with a different brand name printed on the device than the brand in the listing, though the treadmill itself appeared to be identical. 

Amazon reviews are also not always a reliable marker of product safety or quality. An analysis of reviews with Fakespot, a website that uses an algorithm to evaluate the quality of reviews for products sold online, found issues with the reviews on a number of under-desk treadmills. Some reviews appear to be inaccurate, and reviews on any given product could be misleading.

Many of the under-desk treadmills that we tested and don’t recommend have a warranty of only 1 year or less, with a number of exclusions. Plus, customer service is reported to be unhelpful based on reviews. 

All these factors combined indicate that when it comes to under-desk treadmills, buyers should take caution, especially if looking for a bargain product, according to Bogdan. (Read more about the results of our tests of nine under-desk treadmills.)