Your Period + Performance: understanding your monthly cycle to optimize your running

Your Period + Performance-how to manage symptoms to get the most out of your running.png

Starting my period the day we left for Italy didn’t just seem inconvenient (who wants to deal with the heaviest flow day on an 8-hour flight?), but I thought it spelled certain doom for my race at the World Snowshoe Championships. 

Turns out I couldn’t have been more wrong, well except for that super inconvenient part about flying across the Atlantic stuck in the middle of a row with Aunt Flo.

I went on to have an amazing race, placing 9th at the World Championships and finishing 4th American in a competitive field. I didn’t connect the dots on this standout performance and it’s placement in my cycle until I after I arrived back home and a few months later picked up a copy of ROAR by Dr. Stacy Sims.

A few chapters into her book and I realized I didn’t really know my body at all. I couldn’t name the phases of my cycle and didn’t really understand the cyclical fluctuations in hormones and how they affected athletic performance or my life as a stay-at-home-mom/entrepreneur. 

How your monthly cycle can impact running performance

Getting to know my body

Like your average teenage girl I started my period at age 13. The first time I used tampons I became incredibly sick: fever and vomiting. I remember lying in bed while on vacation with my family, staring out the window and watching the trees outside swirl around like they were dancing--presumably toxic shock syndrome.

I had my period for another few years until around 17 years old I stopped having a period at all. The onset of amenorrhea* was about the time my dieting turned into a full blown eating disorder. From there I was put on oral contraceptives to give me a regular period and remained on them for the next 11 years until I became pregnant with my first child at age 28. 

I never really took much time to track or pay attention to my periods and considered my period simply an inconvenience that often brought moodiness and sometimes cramping and fatigue. I always assumed that racing during my menstrual cycle was a sure detriment to performance.

Dr. Sims book, ROAR told another story. The lower hormone phases of the menstrual phase and early follicular phase were actually ideal for peak performance. A fact that seemed to ring true with my own experience and past performances once I took a look at them in the context of my monthly cycle. Almost all my best performances (like the World Championships in 2019, the National Championships in 2018 and Loon Mountain Race in 2019) coincide with the menstrual or follicular phase and some of my worst performances fell in the luteal phase (like my DNF at Pineland and Mt. Washington in 2019). 

Making Sense of It All

The more familiar I became with the different phases of my cycle, the more things started to make sense from fluctuations in performance to specific food cravings. A deeper dive into the supporting research* that Dr. Sims uses in her book led to a better understanding. But I needed to “see” it. I’m a visual learner, I have a hard time recalling information unless I see it in some sort of visual form. So I created a graphic that would help me remember all the phases, correlating symptoms and effects on nutrition and performance. 

Understanding your period for peak performance.png


During this phase your body eliminates the thickened lining of the uterus. This process can often be accompanied by cramping (as the uterus contracts), fatigue and headaches among other symptoms. 

Athletes should watch for symptoms of anemia during this phase, especially if your period is characterized by heavy bleeding. 

Because estrogen and progesterone are lowest during the menstrual phase it is actually an optimal time for peak performance if your can manage the associated symptoms. [Dr. Sims has specific recommends managing more severe symptoms in her book-which I would highly recommend for a deeper dive into the topic and practical application via recipes and more. You can find her book HERE.]


During the follicular phase the brain releases follicle stimulating hormone (FSH) and luteinizing hormone (LH) which triggers the growth of eggs in the ovaries. Estrogen is lower at the beginning of the follicular phase and rises towards the end of the phase as the body gets ready to release a mature egg. 

Lower hormone levels in the beginning of the follicular phase make it ideal for peak performance, so it is a great time to race or focus on endurance efforts and strength training. 


During ovulation estrogen rises and then peaks as the mature egg is released. Higher estrogen can inhibit carbohydrate storage, so longer, endurance efforts require taking on carbohydrates regularly. Lower progesterone means it’s easier to maintain muscle, so high intensity exercises and strength training are beneficial during this phase. Blood sugar is unstable, often resulting in cravings--so carbs, again. 

Focus on taking on more complex carbohydrates during this phase to fuel your body’s demands.


During the first part of the luteal phase estrogen and progesterone are highest, preparing the body for potential pregnancy if the egg is fertilized. These high levels of hormones can cause symptoms such as bloating and fatigue. The high hormone phase is the least optimal for performance since the body is preparing for potential pregnancy. 

Hormone levels drop if the egg goes unfertilized and the body begins to prepare to shed the lining of the uterus, so the later stages of the luteal phase, right before menstruation begins, are ideal for peak performance. 

Because progesterone and estrogen are high, it is harder to make and maintain muscle, making it essential to refuel after workouts with protein. Performance in heat and humidity can be more difficult during this phase due to elevated core temperature and reduction in blood plasma volume. Pre-hydrating and hydrating with an electrolyte drink is essential. 

How I’ve Used the Information

All this information has impacted the way I nourish and hydrate my body as well as how I view performances in training and racing. 

To get a better handle on tracking the four phases of my cycle I downloaded a period tracking app that was slightly more in-depth than the one I was using. I like both Fitr Woman, the app used by the USA Women’s Soccer Team or My Flo. I’ve used both and find the recommendation of Fitr Woman to be more in-line with my needs as an athlete, however the layout and navigation of the MyFlo app is more streamline and slightly more holistic in nature (admittedly not geared towards athletes). Not only do these apps track your monthly cycle, but contain tips and information regarding training, performance and nutrition. 

Now that I have a good handle on what is going on in my body here are some of the things that have changed: 


Period on race day? YAY! I’m primed for a great performance. I think the negative connotation of having your period on race day affects your mindset towards race performance. Conversely, if you find yourself racing during mid-luteal phase when things are not ideal, you could easily feel like the cards are stacked against you. The great thing is that if you know what’s going on, you can take pre-emptive action to mitigate symptoms and disadvantages so that you can feel and perform your best. 

Carbohydrates are essential to athletic performance in female athletes


Yay! I need carbs. All women need carbs. It’s true WE NEED carbs and when you deny your body what it needs you could potentially set yourself up for some serious cycles of bingeing/guilt/feeling crappy. So here’s what I do:

  • Higher carb breakfast: during the luteal phase and ovulation I opt for a higher carb breakfast. Like oatmeal and fruit or eggs, toast and a banana, a baked potato loaded with sauteed vegetables, avocado and a sprinkle of feta cheese is super yummy too. I’ve found that a high carb breakfast is a great boost and mitigates that ‘hungry-all-day’ feeling.

  • Give into cravings: give in to your cravings. Do it. Have the thing you really want in a portion that satisfies you and take the time to eat it slowly savoring it. Have a brownie. Don’t make the spinach-infused, quinoa version, have a REAL FREAKING brownie. But don’t eat it on the sly, or break off half and say you’ll only have half, or eat it in a mindless way that’s filled with guilt, don’t deny yourself all day to give into your cravings later when your will power is down and you’re tired. Instead give into cravings INTENTIONALLY. Make it purposeful and deliberate and enjoy that food that you’ve been wanting. In my experience, when I satisfy the craving for a brownie or a cookie or ice cream and I have some the cravings go away--and when you do it with intention and enjoyment, so does the guilt. 


Drink some calories. Throw out that food rule you read in SHAPE magazine when you were 17 years old and get yourself some electrolyte drink with calories. I’m typically pretty good about hydrating throughout the day with water and non-water beverages like kombucha, tea and seltzer, but I was reserving electrolyte drinks only for the day before a race or day of a race. I just didn’t think I needed it. Now I’m drinking 20-40 oz of an electrolyte drink daily in addition to the water and non-water beverages I was already consuming.  My go-to products: Anytime Hydration from Skratch Labs, Nuun’s new Endurance Formula and OSMO. 

Hydration is especially important during the high hormone phase of your monthly cycle .png

Moods + PMS Symptoms: 

Thankfully, I’ve never had severe symptoms associated with my period. I have mild cramping, some bloating and maybe a rogue headache or two. Honestly, I’m only aware of these symptoms now that I am tracking my cycle and not just the start and end date of my period.

Though my physical symptoms are minimal my mood swings tend to be severe, but I think I always denied the fact that I got moody around my period. Admitting your period affects your moods feels like a very un-femenist thing to concede. 

Now I see the correlation between the high-hormone phase of my period (luteal) and an uptick in anxiety and depression. I have at least one day per cycle where I feel as if my world is crashing down because I am not enough. My life feel irreparably doomed to failure. I’ve actually started setting reminders in my phone to let me know that the world isn’t ending and that I’m enough and I’ll feel like my normal go-getter self in a few days. Knowing that some of your biggest sources of fear and self-doubt are coming (spurred on by hormones) gives you a better handle on dealing with the potential fallout. Now I know that the luteal phase is the perfect time to really hone in on daily meditation, journaling and communicating with the people around me that I need a little extra support (ie “Kids! Stop banging on the bathroom door and let me pee in peace!”). 

Why your period is important + A note on RED-S (Relative Energy Deficiency in Sport formerly called the Female Triad)

Your monthly cycle and the subsequent shedding of the uterine lining (if you are not pregnant) is the body’s signal that a major system in your body, the reproductive system, is working. 

The loss of a regular period due to undernourishment and high levels of activity can result in athletic amenorrhea--which is what I experienced during my teen years and early adulthood. Amenorrhea is just one sign of RED-S, however it is not the only sign. Becoming familiar with the warning signs of RED-S and seeking help is critical for continuing to enjoy the sport of running competitively or recreationally. 

Regular menstruation can also be suppressed by oral contraceptives, IUDs, shots and implants.  It seems as if more women are choosing contraceptives as a way to manage or eliminate their period all together. However, research hasn’t caught up with the potential effects of long-term use as it relates to bone and breast health, says endocrinologist at the University of British Columbia, Jerilynn Prior in an article for NPR.

Even if your monthly cycle is inconvenient--painful even--it seems that it’s actually a critical piece to your overall health. And the better you understand it and the changes it produces in your body, the better you’ll be able to manage symptoms and perform optimally, whether that’s as a stay at home mom or a competitive athlete. 

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