One of the most common emails we get goes something like this: “I get plenty of sleep and eat right, but I’m always tired. Got any intelligence to put the spring back in my step?” We do. Here are the facts and fixes behind 4 common but unusual reasons for that run-down feeling...

#1: **You're taking a new medication.** Martin Lipsky is a professor at the Feinberg School of Medicine in Chicago. He says that antihistamines, antidepressants, pain meds, and beta-blockers can cause fatigue even if drowsiness isn't listed as a side effect! So, if you start a medication and your energy level drops, talk to your doctor about switching drugs or dosages.

Energy drain #2: Slouching. Scott Bautch is a spokesman for the American Chiropractic Association. And he says that looking down uses five times more energy than holding your head upright. Poor posture also decreases blood flow to your brain by as much as 30-percent! To improve your posture, try doing 20 shoulder rolls twice a day.

And finally: You’ll have less energy if you’re lonely. According to a study in the journal Psychological Science, people who feel isolated wake more frequently during the night than those who don’t. Experts aren't sure why, but psychologist Robert Thayer says there’s a simple cure: Just pick up the phone and call a friend... Though you might want to wait until morning.