Elite and some collegiate runners have access to underwater treadmills to get in their aqua-jogging. The runner enters the water and then runs on the treadmill as they would normally (albeit at a slower pace). Deena Kastor used one in her training for the 2005 Chicago Marathon after sustaining an injury. However, most runners won’t have access to this technology at their local gym. For those runners, there are a couple of alternatives.
For this form of aqua-jogging, a runner only needs a pool and special flotation belt. The belt holds you up in the water, allowing you to move your legs in a running motion to propel you through the water. With this form of aqua-jogging, there is no impact and the water is providing the resistance to make your legs work.
The simplest way to aqua-jog: all you need is a shallow pool, waist to chest high. You can either jog forward if there is room (like in a lap pool) or run in place. There is some impact because your feet are coming in contact with the bottom of the pool, but with the water supporting some of your body weight, it is minimal. Since you will be jogging in place or down a lane and back, it will be easier to base your workout on time instead of distance.