How Your Period Affects Your Running

Hormone levels affect almost all we do: how we sleep, eat, drink, feel, and run. Yet, little is really known about how your period affects your running.

The truth is: it can affect it, a lot.

I remember leading up to my fall 2019 marathon and Olympic Trials Qualifying attempt in Indianapolis and stressing that my “time of the month” was going to fall on the day of the race. I worried about how my PMS symptoms or period symptoms would affect my running performance, even considering taking birth control to manipulate my cycle.

I scoured the internet to find out if this could help or hinder my race results. But there seemed to be no verdict. (The first day of my period was the day before my race and thankfully did not seem to have too much of an impact).

Related: Lessons learned from my injury

Ellie Somers is the founder of SISU Sports Performance & Physical Therapy
Ellie Somers is the founder of SISU Sports Performance & Physical Therapy

So, I turned to expert Ellie Somers of Seattle-based SISU Sports Performance and Physical Therapy to answer my questions about how your period affects your running. Ellie is a former high-level soccer player and is currently the physical therapist for the United States Women’s National Australian Rules Football team. She is also a run coach and lift coach who works closely with recreational and elite level athletes.

Ellie answered all my questions about how your period affects your running.

And, here are some key take-aways:

  • Your period is not a curse. It can act as a performance-enhancing drug.

    menstrual cycle phases
    Menstrual cycle phases
  • How your period affects your running depends on the individual. Track your symptoms! There are plenty of apps to do this, or you can go old-fashioned and put pen to paper. I recently have found that the day before period I have extra energy, oddly enough. I always assumed it would be the opposite. That’s because of the next point…
  • Getting your period on race day doesn’t have to be doom and gloom! For some women, this is their optimal time for training.
  • Missing your period regularly is NOT normal and can have serious detriments. 

Below is my conversation with Ellie about all things menstrual cycle and running.

How Your Period Affects Your Running

How do our periods affect our running including performance and how we feel?

Your period is what is known as an “ergogenic aid.” Which means it is a performance enhancer. It is like a woman’s very own, built-in, performance-enhancing drug. Having your period as a runner or athlete is critical to achieving your top performance. If your performance is something you care about, you should care if you have lost your period, have not started your period, or if it has become irregular with little to no explanation. This needs to be addressed.

The symptoms of your period can certainly impact how you feel when you show up to a run. You might feel fatigued, cramping, or irritable. All of which have the potential to influence your performance. With that being said, we know that running during your period isn’t dangerous. 

Is there a better time to train hard or easy during our cycles?

Right now, the evidence on this is inconclusive and really has not provided a clear direction other than to say that athletes should take an individual approach. There have been some studies that show during high hormone phases  (such as the luteal phase where progesterone levels and estrogen levels are high),  you might be more apt to train a bit harder and during low hormone phases (such as the follicular phase – during your period), you might be more apt to rest and lay low.

However, women’s health expert Dr. Stacy Sims says the opposite has been found to be true: “Your sex hormones are at their lowest point the week that you’re on your period. This is when your body is more resilient to stress and a great time to nail your high-intensity sessions because you recover better. So never let someone tell you that you should expect to feel flat, tired, and sluggish because you have your period. That’s a myth.”

But how one feels during their period and how it affects their physical activity is very individual. As a coach and physical therapist, the MOST important thing for an athlete to know is what their individual needs are to training. To figure that out, you absolutely need to be tracking your menstrual cycle and menstrual symptoms including fatigue, blood flow, menstrual cramps, headaches, mood swings, breast tenderness, and motivation. 

Ellie Somers of SISU Physical Therapy is a run coach and strength coach
Ellie Somers of SISU Sports Performance & Physical Therapy is a run coach and strength coach

Most training cycles have us doing a hard workout 3 times a week. Are there considerations to take in when doing this during a fatigue part of the cycle?

I think it is critical as an athlete to understand that all of our life stressors can impact our training output (paces, HR) any day of the month, regardless of where we are in our menstrual cycle. Just as you might expect a lack of sleep to impact your training outputs, so might heavy menstrual bleeding.

This is not a result of a person’s fitness, but really a result of a person’s readiness to train on any given day. Things that make us “ready” to train include good sleep, nutrition, adequate recovery, hydration, energy levels, and more.

Related: How to Tell If You Have Low Iron

Okay, so is getting your period or having PMS on race day a good or bad thing?

It seems to me that there is conflicting info on this which is why it is also so important to take an individual approach. There are some cultures that will not let female athletes perform when they’re menstruating and see it as a time of rest.

I think it all comes back to understanding and knowing the individual. Getting your period on race day may be good news for some women. Some female runners feel most ready those days, whereas others may be vomiting in the bathroom because they feel so ill from the hormonal fluctuations and painful periods. 

I view it as neither good nor bad, but ultimately up to the athlete to decide how they wish to train that day and in those days during menstruation.

Related: What to Eat During Your Period

Have you seen race day endorphins overpower typical hormonal lethargy and ickiness?

One cannot compete with race-day high. It will win ALMOST every time. Nothing beats it in terms of performance because of ALL of the other factors that increase adrenaline with that. Things like pressure, competitiveness, audience, cheering, it’s the ultimate performance-enhancing drug…a race. But also make sure you are eating a nutritious diet during your period including iron-rich foods.

Read more on what to eat during your period here.

Are there any interventions you suggest to decrease the unpleasant menstrual cycle symptoms in our training?

We know exercise is incredibly helpful to all of these symptoms. Some might find that easy, aerobic exercise is just what they need, whereas others might find that higher intensity helps alleviate those symptoms. The best intervention is the one that works best for you, which just brings me back to track your symptoms so that you can figure that part out on your own.

If you have heavy bleeding, consider different period products such as period underwear or a menstrual cup. You can also talk to your doctor about birth control pills

Related: Should Athletes Take Birth Control Pills?

Do you have advice on how to maintain a normal cycle?

As a coach and physical therapist, I think for my role, it comes down to having conversations about periods, educating athletes about the importance of their period, and gaining and garnering a sense of trust with them to share with me if/when their period has changed. I also think it is critical for me to have a basic understanding of the nutritional needs of athletes.

If I have an athlete who has lost a period because of training, I would be referring immediately to a trusted registered dietician, physician, and potentially a mental health counselor. Having a regular period is a sign of good health and losing a period is a very serious issue. These young athletes require a team approach to their care.  

Related: RED/S: The Danger to Female Athletes

Learn more about the work Ellie does, including workshops related to menstrual cycles and training at her website.

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



8 thoughts on “How Your Period Affects Your Running”

  1. Snap! What a great article. I had my period at the Olympic Trials. I do not feel that it hindered my performance too much. It did bother me though. In track I have found even lesser difference in performance. I can feel terrible before, but as explained in the article- the race high trumped it!

  2. Such an interesting read! I have had friends who complain about getting their period on race day, but the few times I’ve gotten my period during a race or hard run, it tends to help my performance (though it can certainly be annoying logistically).

  3. I struggle the 7-10 days before my period. No energy!! Flat. Any thoughts on that? I can’t even complete workouts in full during that time. It’s that bad! Ugh! But after my period starts I’m back to normal.


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