 A Better Life with Dr. Samjay Gupta. For most of my adult life, I have loved running. Ideally outside, but if it's raining or if I'm crunched for time, the treadmill, better than nothing. You can get a great workout, but you've got to be careful. According to the U.S. Consumer Product Safety Commission, more people are injured by treadmills than any other piece of exercise equipment.