9. Listen to your body. If something doesn't feel right—you experience muscle cramping, develop chest pains, become overly fatigued or winded, feel thirsty, lightheaded or dizzy -- stop and check it out. If rest doesn't seem to relieve your concern, talk to your doctor. That way you can catch potential health problems early rather than risk injury and lose all momentum, Lewis says.

10. Set a goal. Figure out why you want to shed pounds (and whether you even need to) and make sure it's a healthy and realistic goal, Kleiner says. Being able to say "I lost weight!" can be just as rewarding as fitting into your slimmer jeans.