Feeling exhausted lately? These common energy-sapping culprits could be what's causing your energy crisis. Here's how to overcome them, restore your pep and put the spark back in your life.

Energy sapper #1:

Your weekend sleep-in

Catching up with zz-time by waking up late on weekends may sound like a logical way to restore your energy, but truth is, it may leave you feeling more sluggish. The reason: Shifting your bedtime or waking time by two hours or more upsets your circadian rhythms, crucial regulators of your sleep cycle, says Amy Wolfson, Ph.D., author of The Woman's Book of Sleep. When you sleep in on the weekends, you may have trouble falling asleep Sunday night, and wake up feeling tired on Monday morning.

Energy fix: Establish a regular sleep-wake cycle by going to bed and getting up within an hour of the same time every day. And if getting up early on weekends leaves you sleepy by the afternoon, take a short nap or rest.

Energy sapper #2:

Your breakfast menu

Eating your breakfast? Great! You know a morning meal revs your metabolism and fuels your body. But that's only half the equation: Turns out, what you eat is just as important. If your breakfast consists of mainly refined carbohydrates -- such as a breakfast muffin or pastry -- these get digested quickly, causing your blood sugar to spike and crash, and you can find yourself sapped by lunchtime.

Energy fix: Include at least 5 grams of protein in your breakfast. Unlike carbs, protein digests slowly so blood sugar and energy levels stay stable. Tasty choices include: An egg-white omelet with chopped onion and low-fat shredded cheese, high-fiber cereal with skimmed milk, and blueberry milk shake.