A Girls’ Guide to Optimizing Performance with the Flow of Her Menstrual Cycle

By October 20, 2014Women's Running

A Girls’ Guide to Optimizing Performance with the Flow of Her Menstrual Cycle

How to run faster, stronger, and happier and with the flow of your body.

I don’t know about you, but I’ve spent the better part of my womanhood fighting my cycle. As I began to coach myself through my cycles, I learned that it wasn’t all in my head, but my body flowing through its natural course.

I began to chart heart rates, perceived exertion (how hard it felt) and recovery times and learned that for me, everything seemed harder with higher heart rates and effort levels during the days prior to my cycle (high hormonal days). While I felt like Wonder Woman after the onset of my cycle and through the first half of my cycle (low hormonal days). This happened consistently as I trained through my cycles.

At the time, I was training for the Boston Marathon, and multi-day adventure races and began to develop a program that was flow-based. I tracked my cycle like I did my shoes, my training and my nutrition – with great detail. Once I tuned into my body and how things felt as it related to my hormonal flow – I began to shift the higher volume, harder intensity workouts to the first half of my cycle when I felt like Wonder Woman, and then tapered it down to recover and adapt in the later stages of my cycle when things felt harder.

It took time to learn, adjust and go with the flow, but it made a dramatic difference in not only how I trained and recovered, but more importantly, it gave me freedom to embrace and love my body in a way I hadn’t before. Instead of cursing my cycle, I became good friends with it and learned to fully embrace the strength and power of every phase.

Like night and day, high tide and low tide, our body cycles through the core years of our lives. Once we learn how to optimize our lives with the flow, everything changes, and we begin to tap into a strength that can rival even Wonder Woman.

As a coach, I learned that although all pubescent girls and women cycle (or supposed to), that every women’s journey is different, and that every cycle can vary as well. This, my girlfriends, is why there has been lacking research on female performance as it relates to our cycle. Happily, this is changing with the help of people like my friend, and Osmo Nutrition founder Dr. Stacy Sims, who as an exercise physiologist and nutrition scientist, has spent her academic career researching sex differences in endurance sports and nutrition. She’s also the one that coined the phase, “Women are Not Small Men,” which is the key to improving both women and men’s performance down the road.

So, what does this mean for you (or if you’re a dude reading this – you might want to share this with your girlfriend, sister, mother, daughter or girls cross-country team)?

It means, there are three ways to tap into your power, and run with the flow to improve your training, racing and most importantly, your life performance.

[ONE] Tune In

It all starts by getting to know your personal cycle. There are some great apps out there where you can track and develop a better sense of timing, days, and even when you ovulate (which can vary drastically in women, month to month – and doesn’t happen at all if you’re pregnant or using the pill). I use the Woman Calendar App and plug in when I start each month, the intensity of my cycle, symptoms and when I ovulate.

As you begin to track your cycle, you’ll also begin to see if patterns arise as it relates to how what you eat, volume of training, sleep, stress and more. For me and some of my clients, higher volume training phases can lighten and shorten cycle times, while others it can intensify the symptoms. Again, we’re all unique and tuning in is the first step in learning how to find your flow.

For the purposes of learning, I’ve broken the cycle into the four core phases. Like the seasons, we cycle through high hormonal levels (Phases 2 and 3) and low hormonal levels (Phases 1 and 4).

[TWO] Optimize Your Training to the Your Personal Flow

Although you don’t need to have a degree in women’s health, it is important to empower yourself with the knowledge of your cycle. More specifically, it’s key (and cool) to understand the four phases of your cycle and what they feel like

Meet Phase One – also known as the Follicular Phase [LOW Hormonal Phase]

Duration: 7-10 Days

What’s Going On: It’s right after menstruation, and there is an increase in follicle-stimulating and estrogen hormones. It’s also known as a low hormonal phase.

How It Feels: Increase energy, creativity (this is when I love to write), and you may even feel more outgoing and social.

Training Focus: It is a good time to progress mileage or intensity, a building week in your training plan, and also a great time to introduce new workouts or challenges. Dr. Sims recommends including more high intensity, VO2Max, anaerobic and power workouts during the early part of this phase and moving into threshold (tempo) and endurance training as you move into the higher hormone weeks in the later Phase 2 and Phase 3.

Meet Phase Two – also known as the Ovulatory Phase. [HIGH Hormonal Phase]

Duration: 3-4 Days

What’s Going On: There’s a sharp rise in follicle-stimulating hormone, and an increase in estrogen and luteinizing hormones. Testosterone surges and then drops around this time and it’s when we are at our most fertile and when the egg drops and travels to the uterus.

How It Feels: It’s when energy is at it’s highest – you may feel like Wonder Woman and workouts may seem easier at harder efforts.

Training Focus: Continue to focus on high intensity, longer mileage, and higher volume training (high intensity intervals). As you begin to shift from lower hormonal days to higher in Phase 3, you can shift to more threshold effort levels (tempo) as well as include longer endurance workouts as well. This is a great time to race!

Meet Phase Three – also known as the Luteal Phase. [High Hormonal Phase]

Duration: 10-14 Days

What’s Going On: There are increases in hormones including progesterone and estrogen and in the late stages an increase in testosterone as well.

How It Feels: You may feel your energy levels decline slowly through this phase and running effort levels may feel harder than normal. For instance, your breathing rates and heart rates may be higher at your normal training paces.

Training Focus: This is a good time to try tapering in your training – by including a higher mileage week early in the phase (long runs, tempo workouts…) and then begin a restorative phase in the final days leading up to your cycle. Dr. Sims recommends “in the days preceding menstruation, it’s useful to focus on technique and lower volume and intensity workouts.” This can include restorative yoga, easy effort runs and cross-training and shorter endurance workouts – also commonly known as cutback weeks. This is the time to tap into what your body needs – rest, recovery and restoration. It’s like the weekend after a long, hard week.

Meet Phase Four – also known as the Menstrual Phase. [LOW Hormonal Phase]

Duration: 3-7 Days

What’s Going On: Progesterone levels drop to trigger your cycle, and estrogen levels peak and drop and prepare for the next phase.

How It Feels: This, by far is the most readily recognizable of all the phases – you may feel nothing, or crampy, tired, have body aches or cravings and you may crave sleep. Your workouts may hurt, and you may have higher breathing and heart rates at your normal pace during the early to mid-stages of this phase.

Training Focus: This is the time to rest and recover and allow the effects of your training progression to take hold. Your body is craving rest, sleep, nurturing and in many cases hibernation (book on the couch, sleep in late…). It’s also a time when restorative yoga can be beneficial, lower impact workouts (cycling, walking, swimming, elliptical) and shorter, easier effort runs. This is especially true if you struggle with harsh symptoms. Although it may feel like a loss, honestly it is more like letting go and allowing the body to heal and grow stronger. You may even notice more soreness and fatigue if you perform harder intensity or longer workouts during phases three and four.

As you discover the length of your cycle and how you perform in each, you can begin to redefine your new progression and training schedule. The traditional model is to build for three weeks and cutback and recover for one. It’s easy to see when looking at women’s cycles that we have our own unique progression and training paradigm. For some this may mean two hard weeks, one moderate week and then a taper week. For others it may mean three hard weeks and one recovery week.

Regardless of the number of days or weeks, it’s key to develop your training with the flow of your cycle to optimize your performance. Dr. Sims also recommends more time in between hard intensity workouts, as women need more time to recover due to differences in muscle enzymes – so instead of running back to back high intensity workouts, it can be more effective from a recovery standpoint to have 48 hours in between.

[THREE] Adapt Your Nutrition to Your Flow

Although the nutritional conversation is much the same for men and women – eat minimally processed foods, carbohydrates, protein and fat intake, clean foods like fruits and veggies and eat within your recovery window – according to Dr. Sims, who has developed gender-specific Osmo Nutrition products, the before, during and after nutritional needs do vary based on gender.

“The nutritional recovery window is different for men and women. Women have 30-minutes for acute recovery and should drink a 3:1 ratio of carbohydrates to protein – not chocolate milk or soy and lasts up to three hours post workout/race to eat a balanced meal for glycogen recovery. Men also have that critical 30-minute window for protein, but they have up to ten hours for glycogen recovery and they should eat at a 4:1 carb to protein ratio recovery mix.”

That is a significant difference, and one that can make recovery a more efficient process for both genders. Dr. Sims attributes the difference to the metabolism of the muscle during exercise and how much cortisol is released. “Women do burn more fat overall as compared to men regardless of the menstrual phase, but also use carbohydrates as the amount of cortisol released in women is slightly higher because of the greater reliance on fat as an energy source,” sited Sims. In essence, women need more protein to shut down cortisol, and increase the insulin sensitivity window for storing glycogen.

The general nutritional recommendations for endurance athletes are based on body weight;

Protein – consume 1.6-1.8 grams per 2.2 pounds of body weight and up to 2grams for high intensity, high volume workouts. (100 – 127 grams per day for a 140-pound person).

Carbohydrate – consume 4-6 grams per 2.2 pounds of body weight (254 – 381 grams – 140lb person).

Fat – consume 1.3 – 1.4 grams per 2.2 pounds of body weight (82-89 grams/140 lb person).

“Training and race day nutrition is timing and hormone driven,” explains Sims. In general she recommends 10-12ml/ of fluid per 2.2 pounds of body weight per hour, or for a 140-pound person – 21-29 ounces per hour. This changes for women in the high hormone phases (3-4 – as you move towards menstruation). “Women do well with a little protein and branched-chain amino acids (BCAA) before exercise (10 grams of whole protein and 4-5 grams of BCAA) as they help mitigate central nervous system fatigue and help jumpstart recovery by circulating amino acids, reducing the catabolic (breaking down) effect of progesterone,” explains Sims.

During exercise, she also recommends for women to consume a little more carbohydrates in the higher hormone phases (3-4) and if you consume caffeine, to do so with food, as it increases the rate of blood glucose absorption with can cause a hypoglycemic (low blood sugar) level without notice.

Hormonal fluctuations of estrogen and progesterone that affect the reproductive system also affect the fluid balance hormones aldosterone and arginine vasopressin, which balances sodium, water and your thirst.

Specifically, in the higher hormonal phase (peaking at around 4-5 days prior to your cycle), there are changes in our physiology that can dramatically affect our metabolic performance including;

  • Increase in body core temperature, which can decrease our tolerance to heat and impair power and performance.
  • A shift to using fatty acids while sparing glucose for energy, which can inhibit the ability to perform higher intensity workouts at 100%.
  • Elevated estrogen shifts fluid from the blood reducing blood plasma volume by 8%, which
  • Higher levels of progesterone increase the amount of sodium lost putting us at greater risk for hyponatremia and further reducing the available fluid women need for thermoregulation and blood supply to the working muscles.
  • If you’re taking the pill, you’re likely to have more circulating hormones in both the low and high hormonal, causing greater effects to all the above mentioned physiological changes. Dr. Sims suggests that using the IUD can be a healthier option, as it is only a small dose of progesterone which reduces the amount of circulating hormones.

Although this may look like a laundry list of negatives, it’s truly just the beginning of the journey to better understanding how women can properly fuel and hydrate based on our unique physiology. In other words, it’s a game changer girls!

Sims is the first to develop a during exercise hydration formula designed specifically for women (Osmo Active) to counter the effects of our fluctuating hormonal cycles and optimize performance, particularly during the high hormonal phases. She’s also one of the first to research and bring attention to the special nutritional needs of female athletes.

This is a lot of information to digest, but in short, Dr. Sims recommends…

  • Consuming a 3:1 carbohydrate to protein recovery meal or drink within 30 minutes of finishing a workout or race.
  • Drinking 10-12ml/ per 2.2 pounds per hour during exercise. (.33-.47 ounces/ per 2.2 pounds) and including sodium, potassium to aid in better fluid absorption across the intestinal cells.
  • In the later phases of your cycle (phases 3-4), consume a little more protein and BCAA’s before exercise.
  • During exercise and in Phase 3-4 of your cycle, consume a little more carbohydrate.
  • If you use caffeine, it’s best to consume it with food during the Phase 3-4, higher hormone stages of your cycle to prevent low blood sugar issues.

It is important to be mindful to the differences in our female physiology as an athlete and for our life performance. Stay tuned as I learn and write more about this subject matter, one that often keeps me awake at night searching for answers. As I make my way towards menopause, I’m both curious and fascinated by all that we don’t yet know about women and life performance.

I also believe the conversation first needs to begin with ourselves, and how we communicate and understand our life cycles from puberty and menstruation to menopause. When we change the tone of the female physiology conversation away from the negative and more towards empowerment and understanding, the mystery fades and we can embrace more lovingly all of the phases of our life. A big high five if you’ve gotten this far!

Check out:

Dr. Sim’s YouTube Webinars on Women’s Nutrition and Performance here.

Check out Dr. Sim’s Osmo Nutrition here.



  • Esthersays:

    Wao…Very educative. Thanks for sharing this article.

  • …eat minimally processed foods, carbohydrates, protein and fat intake, clean foods like fruits and veggies. I wish girls could take hid of these. They really love processed foods which have too much fat leading them to so much discomfort while having their periods.

  • juliana katukusays:

    yaaa….. this so wonderful, thanks for sharing this good ideas, iwish to practice it.

  • Heathersays:

    Fantastic post! THANK YOU for sharing. I’m one who has struggled with the cycle & am really working to embrace and let go, but also to more effectively use the info I’ve been tracking for years to truly work with the flow and quit fighting most all things feminine. I’ve realized many of us are extra hard on ourselves, trying to prove we are just like the guys, but shifting perspective against competing with them to celebrating what being women can be is much-needed. Your work helps us all be better as OURSELVES… Thanks again!

  • Love,love,love!! Thank you so much. Perfect read! With turning 40 next year, feeling in the peak of my fitness, i too have been looking for more information as well as having 2 daughters (13 and 10) who also are into sport and trying to educate them on their cycles, nutrition and performance!

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.