When normal, everyday fatigue strikes, there are ways to boost your energy levels, says Dr. Salamon. For example:

• Drink a cup of coffee or tea. A little caffeine can jump-start your day, she says. "You don't need more than that, but it can offer a mental and physical lift, especially if you have trouble with morning fatigue."

• Go for a 30-minute walk. "If you can't get outside, walk around your house in bouts of 10 to 15 minutes, two to three times a day," says Dr. Salamon.

• Take a nap. A midday nap can help overcome tiredness later in the day. Keep naps to about 20 to 30 minutes, as studies have suggested that napping for 40 minutes or longer can have the opposite effect and leave you feeling groggy rather than refreshed. Also, don't nap too late in the day.

• Skip the alcohol. Cut back on your alcohol intake, or even eliminate alcohol for a few weeks. Men may be surprised how much better they feel without a daily drink or two.