Surprising energy sapper #5: Too Many Holiday Parties
"The odd hours we keep over the holidays can throw off our body's circadian rhythms, our internal clock,” says sleep researcher Joyce Walsleben, Ph.D., former director of the New York University School of Medicine's Sleep Disorders Center at Bellevue Hospital. "And that can make you feel achy and jet-lagged, especially if your schedule has been irregular for several days."

Feel-better Rx: When possible, strive to stick to a regular schedule, going to bed and waking up at roughly the same time each day (even on the weekends). But if you're having trouble winding down at the end of the night because you didn't get to bed until late the previous evening, have a snack that contains protein and carbohydrates, like whole wheat crackers with peanut butter, advises dietitian Tanya Zuckerbrot, author of The F-Factor Diet. "Peanut butter contains the amino acid tryptophan, which helps produce serotonin, a brain chemical that naturally relaxes you and induces sleep," she explains.

PHOTO: People at a holiday party