We know how it is. The thought of sweating through a workout can turn couch gravity into an absolutely irresistible force.

But here's some good news for slackers: Easy, breezy, light exercise may do more for your energy levels than the hard stuff. So go ahead, put your workout on cruise control. Just this once.

Get up and go . . .
Research shows that a program of low intensity exercise training -- like light cycling on a stationary bike for 30 minutes three times a week -- can reduce tired-all-the-time feelings by as much as 65 percent. And it only takes 6 weeks of light workouts to feel pepped up. Moderate-intensity exercise programs boost energy levels, too, but not as much. (Know what the easiest workout in the world is? It's this.)

. . . got up and went
One possible explanation for the better energy boost from lighter workouts: More vigorous workouts shape you up but also tire you out. So if you're just trying to get off the couch for a change, start slow. Go at whatever pace is comfortable for you -- in a few weeks, you'll feel your tiredness fade. Then you can think about kicking things up a notch. (How fit are you? Check your current fitness level with this easy test.)

Energy Drain
So what's sapping your energy?

• Maybe you're drinking too much of this.
• Or maybe you're not getting enough sleep. Take this assessment to see if you might have a problem.
• Or maybe you've got a food allergy. Here's how to tell.
• Or maybe you need more B vitamins. Here's how a shortage will affect you.

Then again, it could be stress that has you feeling drained. Get stress-reduction strategies from other RealAge members on our Community Message Boards.