With this tough winter that we’ve had, getting motivated to run outside and keep up your half-marathon training mileage can be tough. As an alternative, deep-water running has become increasingly popular in the past 10–20 years. It’s essentially running in place in the deep end of a pool while a flotation vest or belt keeps your head above water . (There are also underwater treadmills.) This can be used as a form of cross training, and it’s easier on the body due to the absence of any weight-bearing while you’re suspended in water.
However, I would caution anyone against completely replacing land running with deep-water running, with the exception of runners with foot or lower-leg injuries that prevent them from running on land. Generally, it should be used as an addition to land training. Running against the water’s resistance demands greater use of the hip flexor muscles, which could lead to hip flexor strain or tendinitis if you add a large amount of this kind of training to your schedule too quickly.
During the winter, another option is to run on a treadmill and supplement that with deep-water running. As land mileage increases, runners can use the pool workouts as extra non-weight-bearing cardiovascular exercise.
Studies have shown that runners can maintain their fitness levels by running in the water. This is especially important for injured runners who want exercise options that won’t aggravate their injuries. Deep-water running has the advantage of letting the athlete use many muscles (although not those of the lower extremities) in the same ways that they’re used while running on land. As in a regular running regimen, the water workouts can be varied to include intervals, tempo efforts, and long runs. Just be aware that heart rate during deep-water running is typically about 10 percent lower than during land running because the cool temperature of the water will cause your heart to beat more slowly.
Julie Khan is a physical therapist in the HSS Rehab Department. She graduated from Columbia University with a Masters and a Doctorate of Physical Therapy. Her clinical interests include post-surgical sports-related injuries and running mechanics. Julie is a runner and has completed more than 20 half-marathons and six marathons.