If you run like a bounding deer on a treadmill, but as soon as you hit the road outside, you feel more like a stumbling, out of breath snail, here's a tip for building your strength and stamina. When you're running on a treadmill, raise the incline. Even a slight increase will make a huge difference. Since the treadmill belt makes running easier by propelling your feet, the incline will add more of a challenge, so you'll end up using more energy. Gradually work on raising the incline over a few weeks, and you'll find that putting a little more stress on the body with an incline will burn more calories and develop more lean muscle tissue. Then when you run outside, you'll have the endurance and energy to run as long and as fast as you do on a treadmill.