You need to find a pool that has a flat surface but most gyms offer this now. The flat pool will help you workout every muscle in your body that’s required for running without the weight of your upper body. This won’t result in an easier fitness session as the water resistance will still give your body a consistent workout. Your body doesn’t have to deal with the landing part of your run so you’ll also avoid injury. It’s a fantastic form of exercise as it helps with muscle toning and cardiovascular strengthening.
Just avoid getting comfortable during a session; keep pushing so you really work your muscles.