Feeling Zapped?

When's the first time you feel tired during the day?

a. When I first wake up, even if I've slept 8 hours every night for a week
b. Morning or midafternoon
c. Whenever I move
d. Whenever I have to deal with my boss
e. After working 12 hours or more

Results: If you answered anything other than e, it could be a sign that the energy systems in your body are slightly or completely out of whack, making you tired even at times when you should feel vital and energized.

See if a sleep issue is behind your fatigue, and consider upping your intake of these four energy-boosting nutrients.

Identify other things that may be stealing your zip: Read "Top 10 Physical Energy Zappers" at our partner site, HowStuffWorks.com.