Should I Run a Race on My Period?

Getting your period on race day is not a death knell to your running goals. In fact, a 2020 study found that a majority of female marathoners actually ran their best during their high hormone phase and during menstruation. If you suffer from PMS and period symptoms, these steps will help you feel better so you can run your best.

You can run a race on your period and perform really well with appropriate measures!

It can seem like the worst thing in the world: getting your period on race day. And many female runners will ask themselves: should I run a race on my period?

And the answer for most people is YES. Yes, you should run a race on your period.


Because of three main reasons:

1) There are indicators that racing during female runners’ “time of the month” can be a performance enhancer.

2) There’s no conclusive research to show that running a race on your period can hurt your performance.

And 3) you can mitigate period symptoms on race day with practice and planning.

Many athletes have asked me if they should change their race or take hormones to alter their period so that it doesn’t fall on race day. But those steps aren’t necessary for most women unless you have symptoms like severe cramping, crushing fatigue, or PMDD that are difficult to overcome on race day.

So, let’s get moving!

How does the menstrual cycle affect running?

There are biological indicators that the menstrual cycle can give you a running performance boost at certain phases, including during menstruation. More on that in a bit.

First, an overview of your period:

  • Phase 1: Menstruation: Your period starts day 1 of your cycle. The period is the shedding of the uterine lining. Hormone levels of estrogen and progesterone are low, potentially making you primed to perform.
  • Phase 2: Follicular phase: The follicular phase is between the first day of your period and ovulation, which typically happens around day 14. During this time, estrogen rises and peaks as an egg prepares to be released. When your period is done, the uterine lining begins to build back up again.
  • Phase 3: Ovulation: This is when the egg is released from the ovary. It typically happens around day 14 (mid-cycle) and hormones like estrogen are at their peak, leading to some PMS symptoms such as mood swings, headache, and fatigue. Ovulation usually lasts about one day.
  • Phase 4: Luteal phase: The luteal phase between ovulation and the start of your next period. Hormone levels including progesterone levels and estrogen levels rise and then drop when your period starts. Then the uterine lining either prepares itself to support a pregnancy or shed if there is no pregnancy. This is when you may experience PMS symptoms.

So, if you are affected by hormonal fluctuations, you’re likely to feel crummy during ovulation (roughly day 14 of your cycle) and during PMS, about days 24-28 of your cycle. Note, that menstrual cycles can last between 28 to 40 days.

(By the way, a new study indicates that you are not more at risk for injury in certain phases of your menstrual cycle).

Related: How Your Period Affects Your Running

racing on your period pin
Pin these tips for running a race on your period for later!

Should I run a race on my period?

Yes, you should run a race on your period. In fact, for many women, running a race on their periods may give them a running performance boost.

According to Dr. Stacy Sims, a pioneer in research on female athletes, during your period is when your estrogen and progesterone levels drop. This lowers your core temperature and widens the range of your heart and perspiration rates, potentially giving you a performance boost.

Sims rounds up how the menstrual cycle may affect your training here.

Related: The Danger of RED/S in Female Athletes

What the research says about running on your period:

The research on running on your period is contradictory and a mixed bag. The takeaway is that how your period affects your running is very individual. Thus, you should track your symptoms including how you feel physically and mentally on the run plus your performance. 

Here are some of the research findings on running on your period:

  • One 2020 study revealed that out of 189 female marathoners, 106 ran their best during PMS (luteal phase). The others had their best performance during their follicular phase when hormones can be high.
  • Another 2020 study of ten female athletes found that PMS (mid-luteal phase) may decrease running economy during high heat and humidity. This is likely because during this phase body temperature rises which can negatively impact running economy—especially in hot weather. However, their performance did not seem to be impacted.

Related: How to Acclimate to Running in the Heat 

  • A meta-analysis and review, also done in 2020, examined 51 and 78 studies to find that performance may be slightly reduced right around your period and end of your period (early follicular phase). This conflicts with the theory that women race best on their periods because it is when their hormones are low and they are “most like men.”
  • Two more reviews completed in 2021 found that no conclusion could be drawn as to the link between athletic performance and menstrual cycle phases.

Laura Norris, running coach, has a great overview of all the research on running during your period.

Do you run slower on your period?

Some people may run slower during their periods if their periods are accompanied by intense cramping, headaches, low energy levels, and depression, for example.

These symptoms may be mitigated by the steps below and athletes who experiment with possible solutions.

However, the research shows that some women may run faster on their periods due to the low levels of hormones and core body temperature.

Related: How Running Strides Makes Your Faster

Should I run with period cramps?

Yes, you can run with menstrual cramps and heavy blood flow. In fact, there is evidence that running with period cramps could lessen your cramps.

Running releases endorphins that block your brain’s pain receptors. Running also improves blood flow. Your period cramps are caused by your uterus contracting and cutting off circulation which sends pain signals to the brain. Running opens the blood vessels to help reduce menstrual cramp pain.

Your period cramps are also caused by prostaglandins which are involved in inflammation and pain. NSAIDs such as naproxen (Aleve) and ibuprofen (Advil or Motrin) block this effect. So, if running doesn’t help, or you feel like you can’t possibly run because of the pain, take these medications to alleviate your period pains.

Related: Train Your Gut to Stop Runner’s Stomach

If you know when your period is going to start, take them a day or so before. I am never 100 percent sure when my period is going to start, so I have the bottle ready for when the cramps begin. It works.

Sims also suggests supplementing with magnesium, zinc, and omega-3 fatty acids in the week before your period to help reduce cramps and tummy troubles and raise energy levels.  

Related: What to Eat On Your Period

Are iron levels lower during menstruation?

Pin these tips for running a race on your period for later!

Research shows that your iron levels may be lower during your period. Iron is essential for helping move oxygen from the lungs to the rest of the body while running. So low iron can negatively impact performance.

Related: How to Fix Low Iron in Female Runners

It’s important to note that not all women will experience low iron levels. However, it’s important to also note to get your blood levels checked ever 6 to 12 months. If you are low in iron or ferritin, or borderline, talk to your doctor about taking an iron supplement.

You may also make a conscious effort to eat more iron-rich foods such as meat, eggs, and leafy greens—and cook in a cast iron skillet.

Related: The Top Ten Best Supplements for Runners

Should I wear a tampon while running?

You can wear a tampon while running but you need to consider how heavy your period is and how long you will be running.

If your flow is heavy and you’re running for more than 2 hours, you may consider using a menstrual cup which is a silicone device that can be worn for up to 12 hours, cleaned, and reused.

Other options include running with a sport compact applicator tampon, tucking a spare into your pocket, and changing in a porta-potty. (For most races, time is of the essence, so consider if you’re willing to add a minute or more to your race time to do this).

You can also wear reusable period underwear such as WUKA. Or, opt to free bleed as Kiran Ghandi did in the London Marathon.

I advise against running with a pad as that can lead to chaffing and bunching.

These are all options for you to weigh in preparation for racing on your period.

Below are tips for running a race on your period so you can take advantage of the ergogenic aid.

Your Racing on Your Period Action Plan

Track your period.

The most important thing you can do to help you train with your period is to track it. Tracking your cycle can make sure you have a regular period which is a sign of good health and vital to women’s health. Write down your symptoms from your mental state to your physical feelings.

How did you feel before, during, and after your run? What was your performance like?

Be very specific and look for trends. There are several apps like the Clue App and some built into fitness trackers such as WHOOP (get a $30 discount on WHOOP here), that help you keep track of your cycle and training.

Train during your period and PMS.

You won’t know unless you try, so don’t shy away from training on your period and during PMS. This is the time to be incredibly aware of how you feel and perform…and what works and doesn’t work for you. Do you run long runs. Do your speed work. Don’t avoid running during your period. 

Experiment with a menstrual cup during a track workout. Or, see if you can do a long run with Advil without tummy troubles. Or, take magnesium, zinc, and omega-3 fatty acids during PMS and see if it makes a difference.

Just as you practice fueling for long runs, practice how you will handle PMS or your period on race day.

Related: Marathon Fueling 101: What Runners Should Eat

Dress the part.

Dress so that you feel the most comfortable and empowered while training on your period. Some people opt for looser-fitting waistbands and dark double-lined shorts. Some don’t care. Do a dress rehearsal to know what is best for you.

Embrace the race day vibes.

Even if PMS or your period makes you feel lousy, do not underestimate the power of race day excitement. You will be nervous. You will be excited. You will have doubts.

But don’t let your menstrual cycle be one of those doubts. Embrace the nervous energy and channel it to your performance.

Remember, three things:

1) There is no conclusive evidence that your cycle is going to hurt your race day performance 2) Paula Radcliffe broke the marathon world record on her period.

3) You are one tough mother runner who can overcome anything!

If you want guidance with your running goals, check out my run coaching services. Also, be sure to check out my free training plans:


Leave a Comment


Download my FREE FULL MONTH of strength workouts for runners!

Looking for a free running plan? Email me at [email protected].

* indicates required

You have Successfully Subscribed!