The August 2009 issue of Triathlete Magazine featured an article titled “The end of Running Injuries.” Written by yours truly, the piece introduced readers to the Alter-G antigravity treadmill, which, I claimed, “has the potential to completely eliminate traditional injury setbacks from the life of any runner (or triathlete) who has access to a machine.”

This hyperbolic-sounding statement was based on my personal experience of testing an Alter-G at a Los Angeles physical therapy clinic. While on the machine, which allows the user to run at anywhere between 20 and 100 percent of his or her full body weight, I could not imagine a single injury I’d ever suffered (and I’d suffered them all) that I couldn’t have trained through uninterruptedly with one of these babies. Of course, injured runners can usually ride a bike and can almost always run in a pool, but unlike these traditional cross-training activities, running on an antigravity treadmill is not an alternative to running—it is running!

The one big drawback to the Alter-G, as I noted in the same article, is accessibility. Although the cost of the cheaper consumer models has come down substantially over the last decade, they’re still far more expensive than a regular treadmill. You can rent time on a machine at some high-end endurance training facilities and physical therapy clinics, but that cost adds up too. Plus it’s a hassle. I’d have to drive 20 minutes each way to access the nearest machine in my area.

Not long after my Alter-G experience, I read a scientific paper that inspired me to try steep uphill treadmill walking as a sort of poor-man’s version of antigravity treadmill running and found that it worked pretty well. It gets your heart rate up, the movement pattern is very similar to running, and it’s a low-impact activity rather than a nonimpact activity, so it helps maintain tissue adaptations to repetitive impact, making for a smoother transition back to normal running than you’d get from cycling or pool running.

While training for a recent Ironman I did a ton of steep uphill treadmill walking because, yet again, I was unable to run due to injury. As race day drew closer and closer and I kept failing the occasional test runs I did, I became increasingly worried that I was running out of time to get my running up to snuff. That’s when I got the idea to try steep uphill running. At a steep enough incline, running generates scarcely more impact force than walking does. My plan was to first see whether my injury could handle a slow jog at a 15 percent incline, and if it could, to then gradually run faster at progressively lower gradients until I was able to run normally again. In this way I wouldn’t have to wait any longer to start building up my running fitness but at the same time I wouldn’t hinder the healing process.

Long story short, it worked. Twelve weeks before my race, I took the final step in the process, from running at a 4 percent incline to running outdoors. Even then, though, I was unable to run faster than about 9:30 per mile without pain. Knowing I wasn’t going to get very fit running 9:30 miles, I continued to perform my higher-intensity runs on the treadmill, which I could do without hindering my recovery if the incline was sufficiently steep. Six weeks before the Ironman, I ran the Modesto Marathon, finishing in 3:30:46 (8:02 per mile) with moderate pain. Two weeks later, I ran the Boston Marathon in 2:54:08 (6:39 per mile) with only mild pain. Two weeks after that, I won a half marathon in 1:17:58 (5:56 per mile) with zero pain. And two weeks after that, I raced Ironman Santa Rosa, completing the marathon leg in 3:17:02, which was about what I would have expected if I had never gotten injured in the first place.

To be clear, a lot of the actual fitness that enabled me to make such rapid progress came from cycling. I was on my bike seven to nine hours per week throughout this period. But I doubt I would have performed as well as I did in the Ironman if not for uphill treadmill running, which functioned as a bridge back to normal run training. Neither walking nor elliptical running nor pool running would have done that for me.

Want to give steep uphill treadmill running a try? Excellent. First, go and get yourself injured. Next, hop on a treadmill and find the shallowest incline that allows you to run without pain. If it’s quite steep (15 percent or close to it) and you’re not a very fast runner, you might not be able to run at any speed without workout really hard. In that case, start with intervals, alternating short running bouts with walking. When you feel ready, lower the belt angle a few degrees and give that a try. If you can run pain-free at this new incline, do so until you ready to lower the belt again, and so on until you’re back to normal running. 

Genius!