Image courtesy of Prevention

If the sound of your alarm clock makes you want to cry scream, or throw something (we've been there too), it's time to stop spending your days groggy and grumpy, grab your sneaks, and get moving. Now, we know what you're thinking: But I'm too tired to exercise! Before you toss this issue aside, however, give us a moment to explain.

Research shows that regular aerobic exercise, such as a brisk walk or a heart-pumping Zumba class, can make it easier to fall asleep faster and stay asleep longer. Yoga has also been shown to be an all-natural sleep aid. A study published in the Indian Journal of Medical Research found that insomniacs who practiced yoga for 6 months fell asleep 10 minutes faster, slept an hour longer, and woke up feeling more refreshed than insomniacs who didn't practice yoga.

Insomnia Cures: 10 Simple Sleep Remedies

Of course, all that lab research doesn't mean a thing if it doesn't work in the real world of work deadlines, financial worries, changing hormones, and a slew of other variables that can make it difficult to sleep soundly. So to see if adding a little sweat to a daily routine would really help the average 40-plus woman sleep better, we asked 15 previously sedentary and sleep-deprived women to put the theory to the test. The youngest was 40; the oldest, 64. Their challenge: Aim to do 30 minutes of moderate to vigorous aerobic activity 5 times a week, as well as a few relaxing yoga poses before bed, for 5 weeks.

And guess what? It worked. At the start of the program, the women had trouble either falling asleep or staying asleep--or both. Four of them took over-the-counter sleep aids regularly. At the end of the program, everyone was sleeping more soundly on a regular basis--they found it easier to fall asleep and stay asleep naturally, with fewer wakeful periods during the night. Even 64-year-old Lorenda Murr, who had taken prescription and OTC sleep aids for more than 8 years, slept well. As a bonus, the women had more energy, and each lost an average of 7 pounds and 8 inches; some women dropped as much as 9 or 10 pounds.

"I've had trouble staying asleep ever since going through early menopause at age 37," says Dana Dornburgh, 41, a high school guidance counselor in Holland Patent, NY. "It was normal for me to go to bed at midnight, lie awake from about 2 until 4, and then get up for work at 6 AM. I was exhausted all the time and reached for sugary snacks like chocolate to get through the day. But once I started exercising, I began sleeping consistently through the night. I have also dropped 6 pounds, feel great, and no longer find myself craving an energy boost from candy."

Exercise Helped Real Women Score More Shut-Eye

Laurie Schmidt, 53, an ad designer in Siren, WI, used to wake up 12 to 18 times throughout the night, sometimes lying awake and watching the clock for up to an hour. "It was awful--I was averaging only 4 hours of solid sleep a night. Often, I'd end up taking a sleep aid and wake up with a groggy headache," she says. The good news: Soon after upping her activity, she saw a huge, positive change in her sleep habits. While Schmidt still wakes up for a few minutes 2 or 3 times during the night, she no longer has trouble falling back to sleep. "Now I walk almost daily, even if it's cold out. The yoga helps me relax and signals my body that it's bedtime. You hear myths that once you hit menopause you'll never sleep well again, but exercise changed that for me."

So how does sweating help you snooze? "Exercise releases feel-good chemicals that boost your mood, which seems to reduce tension and anxiety that may interfere with your sleep," says Shawn Youngstedt, PhD, an associate professor in the department of exercise science at Arnold School of Public Health who has studied the exercise-sleep connection for nearly 20 years. "It also has a calming effect on the nervous system, which may increase the quality and duration of sleep." Putting your body through a workout will also help ensure that you're physically tired by the time you crawl into bed; if you sat at a desk all day, pent-up energy could keep you tossing and turning.

To Drift Off Gently and Naturally, Try These 7 Natural Sleep Inducers.