What is an Anti-Gravity Treadmill?

When you hear the words “anti-gravity treadmill,” what do you think of? Probably something connected with space and maybe something that looks like a bubble, right? It turns out that you’re not wrong.

Anti-gravity treadmills look pretty crazy like an enormous balloon space suit for your lower body that you jump into, but they are quite useful for athletes and others dealing with injuries. So let’s dive into what exactly the anti-gravity treadmill is because it’s certainly a lot different than our normal conception of treadmills.

How Does It Work?

A biomechanics researcher at NASA Ames Research Center named Robert Whalen invented the anti-gravity treadmill in the 1990s. Whalen wanted to address the difficulties discovered with the previous treadmill on the International Space Station which used a bungee system to anchor the astronaut to the treadmill. This was not successful for two reasons: one, it doesn’t really replicate how people run on Earth, and, two, it was pretty uncomfortable to run in.

Whalen’s design encloses a treadmill and places the lower body of the astronaut—the people the treadmill was originally designed for—in an airtight chamber. Air pressure inside the chamber is lowered, pushing the astronaut down and simulating gravity. With the old ISS treadmill, astronauts could only run at about 60 percent of their weight on earth, whereas with an anti-gravity treadmill, astronauts can exercise at their normal Earth weight in space. In 2005, Whalen licensed this patented design to Menlo, Park California-based AlterG.

Anti-gravity treadmills use a difference in air pressure between the atmospheric pressure of the upper body—since that is above the chamber—and the higher pressure of the lower body to offset your weight. It’s like standing in an inflatable raft while someone else blows it up. You don’t feel the pressure because it doesn’t take much to lighten you up, making it easy to add extra miles without worrying about injuring yourself.

To use one, you zip neoprene shorts at the waist to an airtight bag that surrounds the runner’s lower body as well as the running belt and attaches to the treadmill. Next, you’ll choose a running speed and decide what percentage of your weight you want to remove. After you’re sealed in, the system will calibrate to adjust to you and the input it received. You’ll be able to see more on the monitors than a normal treadmill, including cadence, strike force, stance time, and stride-length symmetry.


Retired Staff Sgt. Jesse Whitmier exercises in the NASA-developed anti-gravity treadmill. Courtesy of the US Air Force

What Are Some Benefits?

With anti-gravity treadmills, physical therapists can successfully treat injuries and conditions like shin splints, total knee or hip arthroplasty, foot and lower back pain, and even TBIs. If individuals use an anti-gravity treadmill to return to activity as soon as possible while injured, they will experience little muscle atrophy and decreased swelling. Professional athletes use anti-gravity treadmills frequently to recover from injuries.

Even if you aren’t injured right now, an anti-gravity treadmill can allow you to go farther with less impact, preventing future injuries. You can try running between 85 to 95 percent of your normal weight, and you’ll run with a higher turnover. Runner’s World recommends a tempo workout of 5 x 5:00 at half-marathon pace with 1:00 of easy running to recover. A low impact workout like this can help you stay healthy and uninjured as you increase the number of miles.

In sum, there’s a lot that an anti-gravity treadmill can do. It can assist with and optimize rehabilitation as well as improve recovery times by restoring normal walking and running mechanics as it supports the healing tissue.

Is It For Me?

NASA has great things to say about anti-gravity treadmills, noting that they can be used for professional and college athletes, injured military members, seniors, and a variety of patients who are suffering from brain injuries, neurological disorders, athletic injuries, and other stresses on the joints, including arthritis and obesity.

Even if you don’t fit into these categories, an anti-gravity treadmill can help those interested in gaining mobility, strength, and natural movement without undue stress on your body. In fact, a 2012 Stanford study in Medicine & Science in Sports & Exercise even found that runners were able to reach the VO2 max and max heart rate with an anti-gravity treadmill. You’re able to run faster with a workout that simulates the biomechanics and the aerobic demands of normal running.

If you have injuries, want to see if an anti-gravity treadmill can make you an even stronger runner, or just want to run in a bubble, you might want to consider trying out an anti-gravity treadmill. If you enter your zip code on AlterG, it will show you the nearest locations to try out an anti-gravity treadmill. Then you can see for yourself if they’re worth all the hype!

The Wired Runner