It’s easy to blame a bad run on your period. But think about this for a second: Paula Radcliffe set the women’s marathon world record in 2002—a record that stood for 17 years—while dealing with period cramps in the last third of the race.
Your period itself likely won’t affect your running performance, but the symptoms associated with your menstrual cycle might. And considering the fact that more than 75 percent of female athletes report experiencing negative side effects during their menstrual cycle, understanding your hormonal fluctuations and knowing what’s normal for you can help you train smarter and get better results from your running.
You’re probably pretty familiar with the fact that your menstrual cycle is about 28 days long. During that time, there are four phases: menstruation, the follicular phase, ovulation and the luteal phase. An easier way to think about it, says Jason Karp, Ph.D., an exercise physiologist and author of Running for Women, is that the first two weeks (mainly, the follicular phase) begin with the woman’s period and is dominated by estrogen, and the second two weeks (the luteal phase) begins with ovulation and is dominated by progesterone. The luteal phase ends with the start of the period, and the cycle starts all over again.
“In general, a woman can expect to feel better and have better workouts during times of the month when estrogen is the dominant hormone and feel the worst during her period and when progesterone is the dominant hormone,” Karp explains.
Research shows that you might actually experience greater gains in strength and power during the first two weeks of your menstrual cycle. It’s not that your period makes you stronger, per se, but rather your body is more primed to make adaptations. “It likely has to do with estrogen, which enhances muscle recovery from training,” says Karp. Women have also reported less pain sensitivity during the follicular phase, which means this could be the time to really push for PRs.
“Performance is most affected in the few days leading into the period and the period itself,” says Karp. That’s because during the second two weeks of your cycle (mainly the luteal phase), your body just isn’t primed for high-intensity training. For starters, symptoms of premenstrual syndrome like cramps, back pain, bloating, and headaches can start seven to 10 days before your actual period. And studies have found that prolonged exercise during the luteal phase can increase cardiovascular strain, making it feel harder and more exhausting.
“As a guideline, women should do high-intensity workouts in the lower hormone phases of her cycle, and more endurance-type activities when estrogen is elevated,” says Karp. “Estrogen is a runner-friendly hormone: Women should push the endurance training when estrogen is high and cut back when progesterone is high. Progesterone is catabolic, which reduces the body’s ability to recover and build muscle, so when progesterone levels are elevated, women should also increase their consumption of quality protein before and after training.”
Of course, just like PMS symptoms can vary between you and your friends, so can the effect of your menstrual cycle on your performance. That’s why it’s so important to understand your cycle. Fortunately, there’s been a rise in technology that looks to help women better track and inform their own training.
Garmin’s menstrual cycle tracker that lets you view period reminders, cycle details, and symptoms right on your wrist. The tracking itself is actually done in Garmin Connect (the watch app is compatible with the Forerunner, Fenix, and Vivoactive devices); whether your period is regular, irregular, or you get no period, you can log daily symptoms, get period and fertility predictions for up to six months, and read insights into how different phases of your period affect your body—and performance.
“Just like with other Garmin features, you can view a report of your cycle,” explains Jill Kaiser, Garmin’s lead project manager for menstrual cycle tracking. “Once you start logging your symptoms, you’ll start to see trends month to month. That can help you know what to expect during your training, and better understand how to manage that.”
The app even provides tips on how to deal with the different menstrual phases, like taking vitamin E and magnesium to reduce cramps on day one of your period, or remembering to stretch to avoid injuries more likely to occur in the middle of your cycle.
As personalized as you can make the tracking in these types of devices, it’s important to remember that everybody’s body is different. While an app or device can provide standardized advice, it’s still important to listen to what your body is telling you. “Not everyone feels the same way on day five or day 10 or day 27 of the menstrual cycle,” says Karp.
No matter what, you’ll benefit from tracking your period (whether in an old-school notebook or on a high-tech device) just by teaching yourself to pay more attention to your body. “The better we can educate ourselves on our bodies, the smarter we can be in training,” says Kaiser.