Danger Zone: You feel guilty if you don't train at least two hours a day.
Expert Fix: Limit your workouts to between 45 and 60 minutes. After this window, cortisol levels spike while levels of muscle-building testosterone decline. Workouts then become counterproductive to your goals.
Danger Zone: You obsess over eating fat-free meals—or skip meals entirely.
Expert Fix: This preoccupation with eating "healthy" or "clean" foods is called ortherexia nervosa. "Find other hobbies so as not to obsess about food rituals," says MF adviser Jim White.
Danger Zone: You'll sacrifice family, friends, and work responsibilities before missing or even postponing one of your workouts.
Expert Fix: See a counselor or find a support group. A doctor might prescribe an antianxiety medication.
Danger Zone: In the gym, you push through pain, regardless of severe injury or illness.
Expert Fix: Be honest with yourself. If you're hurt, don't work out! "Otherwise, you're going to end up in your 30s or 40s, sidelined with injuries and not be able to train at all," White says.
Danger Zone: You experience nagging muscle/joint pain, headaches, poor immunity (frequent colds and sore throats), insomnia, and find yourself feeling tired—even after resting. (You may also experience a sudden drop in training capacity/intensity or a loss of enthusiasm for sports.)
Expert Fix: Always take two days off a week from weights for recovery—maybe even more than that after three months of hard training. The law of diminishing returns applies to training. Overdo it, and instead of getting stronger, you get weaker and worse.