Your menstrual cycle may be a drag on your mood, but it doesn't have to slow down your workout schedule. For some athletes bleeding is such a burden that they take birth control pills like Seasonique to limit their periods so they don't have to mix training sessions with PMS. But do you really have to change up your menstrual cycle in the name of a good workout? And can exercising when you're bleeding pose more serious risks than simple inconvenience? We scoured the medical journals and talked to top researchers to get the scientific low-down on how your menstrual cycle does (and doesn't) affect your workout:
Your period does not hamper your performance
Top athletes don't let a little bleeding slow them down, and you don't have to either. Turkish researchers surveyed 241 elite athletes about how their menstrual cycle affected their performance. While nearly three out of four women said they felt worse just before menstruation, 63 percent said that their pain decreased during training and competition and 62.2 percent said that they believed their performance was just as good when they had their period as other times of the month. A West Virginia University study found that female runners performed equally well whether tested during the first half or second half of their menstrual cycles. The one caveat may be for women with severe premenstrual and menstrual symptoms, such as serious cramps and heavy bleeding. In one French study women who reported these symptoms performed more poorly on a broad-jump exercise during their period compared to their later in their cycle.
Your period might increase your chance of injury
Women are two to 10 times more likely to get ACL injuries than men, and studies have found clusters of these knee injuries at the start—and just before—menstruation. Why? When Australian researchers looked at the muscle mechanics of women running on a treadmill, they found differences in the way their knees moved during menstruation compared to ovulation. The researchers chalked this up to poorer motor control during menstruation—anything from letting your knee collapse inward when you land to letting your quads do all the work instead of involving the hamstrings and glutes, says Timothy E. Hewett, Ph.D., director of the Sports Medicine Biodynamics Center at Cincinnati Children's Hospital Research Foundation. "The bad news is that there may be an association between a woman's menstrual cycle and her risk of ACL injury," says Hewett, who has been studying the effect of the menstrual cycle on injury for 15 years. "The good news is while we can't change a woman's anatomy or do a lot about her hormones, we do know that we can alter her neuromuscular control and decrease her injury risk by half." In several studies, Hewett and his colleagues showed that when they gave athletes additional neuromuscular training, teaching them how to reduce the load on their knees and ankles and building up strength and coordination in both sides of the body, they dropped their rates of ACL injury, ankle injury and knee cap pain by 50 to 60 percent. He recommends adding single-leg balance work, plyometric jump work (focusing on form rather than quantity), and hamstring and glute strengthening to your workouts twice a week for 15 to 20 minutes.
Your workout can reduce PMS symptoms
The American College of Obstetricians and Gynecologists recommends regular aerobic exercise to help relieve PMS. You probably don't need a scientist to convince you of that! Set foot in the gym when you're PMSing and you'll boost your mood, ward off fatigue and facilitate a better night of zzz's. "I feel best any day of the month if I get going in the morning with a workout," says Anne Kveta Haack, 36, of New York City, who rotates between swimming, running, biking, yoga and light weights regardless of her cycle status.
Your period doesn't keep you from the gym
Most of you are game to hit the gym no matter what time of the month it is. One 2010 study found that women's workout schedules did not change over the course of their menstrual cycle, whether they took birth control pills or not. "We found that regardless of what phase of their menstrual cycle women were they would still maintain the level of exercise they kept throughout their cycle," says lead author Chrisalbeth J. Guillermo, MPH, a researcher from the School of Community Health Sciences at the University of Nevada, Las Vegas. "They would go to the gym and exercise regardless of whether they were menstruating or not." The researchers had expected that physical discomfort might get in the way, but found that women were way more committed to their fitness routines than that.