These are great for people with injuries or the elderly, as they reduce the stress on your joints when you run. Furthermore, it reduces you wight by 80%, reducing the strength and endurance it takes to run more.
The underwater treadmill is also good for athletes who are working out, because it is takes more strength to run through water than running regularly on an ordinary treadmill. This relates to engineering, because engineers had to think about how they would make the treadmill spin under water.
