From premature aging to a compromised immune system, the side-effects of sleepless nights can add up, according to Barbara Harris, editor-in-chief of Shape magazine and author of Shape Your Life: 4 Weeks To A Better Body — And A Better Life! (Hay House, 2002). During her more than 15 years at the helm of Shape magazine, Harris compiled the secrets to what makes or breaks an effective fitness regimen. She says getting in the best shape of your life requires more than just a good workout. In fact, Harris maintains that in order to improve your overall health, you need to take a holistic approach that focuses on seven main areas: sleep, exercise, diet, spirituality, emotions, body image, work.

Sleep is crucial for optimum immunity, Harris says. When you don’t get enough shuteye, your workouts may be less effective and you’re more likely to store fat. But that’s not all. Your ability to manage stress throughout the day is also compromised.

Studies reveal women frequently turn to food to soothe themselves in times of stress. It’s also a fact that many women eat more to raise their energy level. The root of these problems can be traced to the stress-associated hormone cortisol. Initially it suppresses appetite, but later there’s a rebound increase. Sleep experts know the less you snooze, the more you produce this cortisol. Harris says the hormone also depletes muscle via cellular breakdown. As your cortisol levels increase, your muscles weaken and the strengthening exercises you do become less effective.

The good news: you don’t have to lose any sleep over this dilemma. Not when you follow these 10 tips for a good night’s snooze.

1. Get regular exposure to daylight, especially in the afternoon. (Research shows that night-shift workers can improve daytime sleep by working under bright lights.)

2. Prior to bedtime, use dimmer switches or turn off a few lamps to lower the lighting in your home or apartment.

3. Don’t allow yourself to nod off on the sofa. When you start feeling drowsy, get up and go to bed.

4. Use your bedroom only for sleep and sex. Don’t make it a satellite office, study hall or entertainment center.

5. When you can’t sleep, try using imagery and thoughts to relax. Deep-breathing techniques also work.

6. If you haven’t dropped off within about 20 minutes, get out of bed and read or engage in some other quiet activity. Go back to bed when you get sleepy.

7. Put the alarm clock out of sight. Clock watching doesn’t help you sleep — it may even keep you awake.

8. Sleep specialists recommend lying on your back or on your side, not your stomach.

9. Get Fido and Fluffy their own comfy beds. In a study conducted by the Mayo Clinic, half the people surveyed had their sleep disturbed by pets.

10. Only take over-the-counter sleep aids as an occasional emergency measure. You can build up a tolerance to them very quickly. If you find yourself relying on them, see your doctor.