Are your energy levels up to par? Or have you felt tired for so long that it's your new normal?

To find out, take the quick test below, chosen by RealAge experts Michael Roizen, MD, and Mehmet Oz, MD, for their new book: YOU: Being Beautiful.

YOU Test: Zapped
When is the first time that you feel tired during the day?

1. When I awaken, even after sleeping a full 8 hours every night for a week
2. Morning, or at the latest by midafternoon
3. Whenever I move
4. Late afternoon
5. Whenever I have to deal with my boss
6. Not until after a day of working 12 hours or more

Results: If you answered anything other than 6, it could be a sign that your energy systems are slightly (or completely) out of whack. To help you get turbocharged, check your sleep habits, walk daily, drink plenty of water, and cut back on saturated fat and sugar, say the docs. And here are a couple of other energy boosters you may want to explore:

• DHA -- This is the active form of good omega-3 fats, and it helps keep the nerves firing to your muscles. The YOU Docs recommend getting it from either fish oil (2 grams daily) or a DHA supplement (600 milligrams daily).
• Ribose -- This is a sugar your body makes naturally. It's not found in food, but you can get extra in supplement form. Just check with your doctor first, as it's not right for everyone. If your MD gives the green light, you could try 500 milligrams three times a day for a week, according to Drs. Roizen and Oz.

Check out the YOU Docs' other tips on energy-boosting nutrition.

Order their new book -- YOU: Being Beautiful -- and learn new ways to turbocharge your energy, your looks, and your life.

YOU: Being Beautiful -- The Owner's Manual to Inner and Outer Beauty. Roizen, M. F., Oz, M. C., New York: Simon & Schuster, 2008.