The Best Workout for Every Phase of Your Monthly Cycle

iWork with — not against — your body.

But what if exercising during your period — and all of the other days in between — could be easier and more efficient if you trained according to your cycle?

Ladies, let’s be honest: Sometimes just the thought of exercising while on your period can make you want to put away your running shoes and take a weeklong break from the gym each month.

But what if exercising during your period — and the days in between — could be easier if you trained according to your menstrual cycle? It may seem strange, but just keep reading.

There’s no reason to skip a workout just because you have your period (barring an underlying health condition like endometriosis, of course). In fact, if you want to get the most out of your workout, it’s time to start paying attention to what your body is telling you and match your workouts to each phase of your cycle.

Keep in mind that all of the advice below is based on an average 28-day cycle, but yours may be a bit longer or shorter. Also, every body (thus, every cycle) is different, so it’s important to listen to your body and do what’s right for you.

Harness the Power of Your Hormones

It’s no secret that female hormones fluctuate throughout the different phases of a woman’s menstrual cycle. And that rise and fall of estrogen and progesterone can significantly affect your motivation to exercise.

“Estrogen and progesterone are important for helping our bodies produce serotonin, GABA and endorphins,” says Gillian Esser, M.D., a Washington-based OB-GYN and avid exerciser. “If hormones decrease, then these brain chemicals also decrease, so it’s no wonder we feel irritable, sad, lethargic and achy.”

But here's the good news: Dr. Esser also believes that exercise can help combat these lows in mood and energy. “Our brains production of norepinephrine (which boosts energy), dopamine (makes us feel good), serotonin (decreases appetite and depression) and endorphins (blocks pain receptors) increases during exercise,” she says.

And if you’re someone who consistently skips workouts during the first two weeks of your cycle, you might be missing out on a chance to make some significant gains in your fitness level.

According to a 2016 study from Umea University in Sweden, training during this crucial time period can yield greater power, strength and muscle mass than any other time of the month.

iWork with — not against — your body.

How to Work Out During Days 1 to 7

Technically, the first half of your cycle is referred to as the follicular phase. And during the first seven days, Stacy Simms, Ph.D., an environmental exercise physiologist, recommends doing high-intensity interval training (HIIT).

“Because of the drop in hormones, women can access carbohydrate/glycogen easily, as compared to the high-estrogen time periods when we rely more on the slow breakdown of fat,” Sims says. In other words, women can push harder and get more out of short, fast-paced workouts during this time.

But since every woman’s cycle is different, some will find it harder to work out when they’re menstruating if they suffer from any pain and discomfort during this week. If that’s the case for you, light cardio, swimming and yoga can also be good, low-impact options during this time.

How to Work Out During Days 8 to 14

Next, during the second half of this first phase (approximately days 8 to 14) testosterone levels increase, making it an optimal time for strength training, says Josie Ball, D.C., a certified chiropractic sports physician.

“This time frame is great for increasing the body’s ability to build muscle and recover more easily,” she says. So don’t be afraid to shift to a more intense program of weight training or boot camp-style classes.

The key to the follicular phase is to think anaerobic, strength and power.

How to Work Out During Days 15 to 21

Welcome to the luteal phase! This second half of your cycle starts with an initial dip in estrogen. However, your estrogen levels do climb back up, along with progesterone, before they fall again in preparation for your period.

This hormonal roller coaster may decrease your energy levels and cause you to feel sluggish. Your body isn’t primed to work out at very high intensities during this phase, so you should plan to reduce your overall workout load, use moderate weights and stick to steady-state aerobic exercise.

The first part of this phase, approximately days 15 to 21, is good for activities like running, the elliptical, Pilates, barre workouts and body-weight/lighter resistance training.

How to Work Out During Days 22 to 28

In the days leading up to your period (approximately days 22 to 28), your hormones undergo significant changes, with peak changes coming about five days before your period, says Sims.

Your core temperature increases and your metabolism switches away from glycogen and relies on fatty acids, she says. Basically, it takes less time for you to get tired and decreases your heat tolerance, which means you can't work out as hard.

But don't get discouraged! Sims says women shouldn't be so hard on themselves during the days leading up to their period. “Many women feel a lack of ‘mojo,’” she says. “In other words, they can’t push through a hill or sprint when that’s something they ordinarily can do.” She reminds them that this is all physiology, not your personal fitness, so cut yourself a little slack.

She recommends sticking with the same exercises from the first part of the luteal phase: steady-state cardio, Pilates and body-weight work.

Ball also recommends that women take it easy in the few days leading up to their period and believes it’s a great time to engage in activities like yoga, which can help relax the body and potentially reduce symptoms like cramping, breast tenderness and muscular fatigue and soreness.

iWork with — not against — your body.

Go Easy on Yourself

It’s important to be mindful of the differences in female physiology and remind yourself that the ebb and flow of your hormones does impact your fitness level.

You might find it helpful to track your performance during each phase of your cycle. Take notes on sleep, moods, food consumption, energy levels and exercise intensity. Then schedule workouts in advance based on your body’s needs during that part of your cycle.

And remember, if you find that your body is not performing like it usually does, it’s OK to give yourself a break and ease up on the intensity. Like Sims says: It’s physiology — not your personal fitness — that can affect your performance across your monthly cycle.