Do...
What you hate. Many advanced exercisers don't like struggling with things they aren't naturally good at, so they avoid the exercises that really challenge them, says O'Connor. But those are the moves that help build a stronger, more balanced body and prevent overuse injuries. Whether you're avoiding squats, crunches, or stretches, add the moves to your routine two or three times a week.
Work out with someone slower. Once a week, exercise with a buddy who moves at a more leisurely pace. You'll give your body a chance to regenerate, and maybe you'll even have a bit more fun. Fitness fanatics tend to exercise competitively: "That's why this group has a higher injury rate; they're always pushing as hard as they can," says Glass. "You need to take it easy periodically so your muscles can repair themselves and become stronger before your next workout."
Don't...
Be a slave to the numbers. Tracking your heart rate or running time can provide instant, valuable feedback; but when used obsessively, these tools can dampen the joy of exercise itself — or even make you push yourself when you're not feeling 100 percent. "Every now and then, go unplugged and focus your attention on what your body is telling you," advises Tim Church, MD, MPH, PhD, medical director of The Cooper Institute. Move at a pace that feels good, listen to your body, and enjoy the experience.
Eat like an Olympian. Energy bars and sugary sports drinks are necessities for top athletes who struggle to meet caloric demands out on the playing field. But unless you're training for the Ironman, a 200-calorie energy drink and a 300-calorie carb bar can undo all your hard work, says Neporent. Fuel up with three balanced meals and two light snacks, such as fruit and crackers, per day. Any more than that will just go to your waist.