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The Menstrual Cycle and Female Athletes

By: Rick Prince

Female Needs

As we know women and men are different. But what makes them so?  Do they need to train differently?  Women menstruate and with this, hormones fluctuate. This can have a significant effect on how a female athlete may respond to exercise, the demands of her sport and competition. 

Hormones are the body’s chemical messengers that are released by the endocrine glands and circulate in the bloodstream. They regulate mood, sexual function, growth and development, reproduction, metabolism, sleep, temperature – basically everything in the body.  Both men and women produce testosterone, estrogen and progesterone. As a female myself, I have personally seen differences before and after my period. I have outlined some basics on female reproduction, current research and suggestions for female athletes. 

Female Reproduction

There is a balance of endocrine system hormones between the hypothalamus, pituitary gland, and ovaries. The menstrual cycle is 21-35 days long.  The first 14 days (follicular phase) is where the female’s body is preparing the ovary to release a mature egg.  Days 15-28 (luteal phase) is where the body prepares the uterus to fertilize the eggs. The luteal phase is always 14 days, whereas the follicular phase can vary in length. 

The follicular phase is also know as the low hormone phase of a women’s menstrual cycle, and it starts when bleeding begins.  On day 10 or 12 – approximately 2 days before ovulation, estrogen will start to peak again. During this time frame, a female is less likely to feel as much pain, and has increased flexibility in her ligaments. 

The High Hormone phase, or Luteal phase is where estrogen and progesterone levels rise.  These increase causes increases in core temperature, increased sodium excretion in urine, decreased blood plasma volume and premenstrual symptoms (PMS).

80-90% of females deal with PMS. Many take birth control (IUD, oral contraceptives) to lessen the symptoms. Other options include SSRIs (Fluoxetine, etc). Looking at the work of Dr. Stacy Sims – her protocol to lessen these effects is as follows:

  • Starting 5-7 days BEFORE onset of bleeding:
    • Magnesium Glycinate 250-400mg
    • Aspirin 81mg
    • Zinc 30-45mg
    • Fish oil (1000mg)
    • Bloating:  Simethicone
    • GasX 1-2 tablets

An athlete having their period is a sign of health and one can learn to optimize their key workouts based on their menstrual cycle.  The best way to do this is start tracking patterns.  I use a phone app that keeps track of when I get my period and the days between. When an athlete starts doing this, patterns start to arise in respect to symptoms, heart rate and sleep.

Optimizing Training

The good news is that a female’s VO2 max and lactate threshold don’t change based on the follicular or luteal phases. However, during the follicular phase, a coach/athlete can maximize this time because of what happens in the body with hormonal changes.  It’s been found to be the best time to do heavy lifting, maximizing strength and doing intervals. Women typically need less recovery during this time. 

During the Luteal Phase, there may be an increase in resting and training heart rates, efforts may feel harder and so it’s often noted to use effort rather than be strict on HR zones. More carbohydrates are required during this time as well.  It is important to understand that an athlete may need to dial back workouts during this time.

Here are my key tips to women athletes: 

  • Listen to your body. Usually exercise helps with menstrual cramps/symptoms. If it’s difficult, consider easing into the workout, and/or going easier until you feel good.  The body knows best. Consider more aerobic training before your period, and more high-intensity workouts after your period. Use your period to your advantage. 
  • Get a Menstrual App on your phone. Document your period for many months to see how you respond to your cycle and to potentially document when you will get your cycle in the future.  There are several Apps on the market. I currently use: Period Tracker. I use the free version. It has been very helpful in seeing when my period will potentially be, and what I need to prepare mentally for (if for instance, pre-menstrual days fall on a race day). 
  • Consider a day off.  Even with the app I have, I adjust my training daily, as needed. That’s the only way. I have some months PMS affects me so greatly, while others, it doesn’t.  Overall though, I can bet at least one day of complete and utter fatigue. 
  • According to a Swedish study, you can gain more muscle mass by training during the first weeks of the menstrual cycle, from the beginning of your menstruation until ovulation (see citations). Use this to your advantage in your training with higher intensity training, and efforts.   
  • Find a coach (if you desire one), that you can be 100% open with about your cycle. Hormonal changes affect you as an athlete and your coach should be well-versed in this area.  If you feel uncomfortable, and/or you coach doesn’t understand these issues, I highly researching this area as much as possible. It can only help you as an athlete to be able to be open and communicative with your coach. If you’re a female athlete working with a male coach or any coach for that matter, this conversation should be a common one. 

Nutrition and the Menstrual Cycle


Pre-period: (high hormone phase; luteal phase; latter days of days 14-28 in your cycle): Your hormones are somewhat working against you. 

  • Take in a few extra carbohydrates to help with performance/training. 
  • Be diligent on your post-workout protein and carbohydrate intake. Recovery drinks are key here. 
  • Increase your fluid intake. Be diligent in your hydration and sweat loss. Add more sodium and electrolytes/fluids during this phase of your cycle.
  • You can pre-load workouts with sodium and other electrolytes.  
  • Beets and other foods high in arginine can help thin the blood

During your period:  

Increasing your magnesium, and iron levels can be helpful.  I personally make sure to eat more red meat, and leafy greens during this time. Loose bowels (from prostaglandins during this time) is common. 

Race Day:

Pay attention to how your body responds through your app, or in your general training diary. Keeping track can help you understand in advance how you will feel, what you might expect, and you can then make a plan of action when symptoms hit during a race, or lead up into one.  

More Information

As noted above, having your period is a sign of a healthy hormonal balance. If you don’t get your period (either from the use of possible hormonal IUD, or other contraceptives, and/or low body fat percentage), it may be something to discuss with your doctor, and to consider yourself.  I know many professional women who get their cycle regularly (I’m one of them!) and some that struggle to get it without the use of contraceptives.  A healthy woman has a period, period.  If you’re not getting it (and you’re not using a hormonal IUD or other), it’s a sign that stress may be too high, you’re not eating enough, and it should be a RED FLAG!  Lack of having a period can also be a sign of overtraining, and hormonal imbalance. Use your period as a sign of health and vitality.  

Oral Contraceptives. There are side effects to these and I would definitely consult with your doctor on these. Oral contraceptives increase your hormone levels and you can likely consider yourself always in a higher hormonal phase (the time in the cycle we generally don’t perform as well).  I have personally used these in the past, and as mentioned, I also had an IUD. I didn’t like being on oral contraceptives because of this exact feeling. I felt my pre-menstrual symptoms increased and lasted longer. This may not be the case for everyone. As much as I loved not having a period when I had the IUD (the hormonal ones generally take away your period because of the constant levels of progesterone); I found that after not being on it, I had more energy and vitality. It’s definitely something to look at and consider the pros and cons of and to consult with a doctor you trust. 

Many athletes have trained and raced while pregnant or going through menopause.  The best source I have found for details on this is Stacy Sims and Selene Yeager’s book, ROAR – as it goes into detail on pregnancy and menopause.  

I have heard of some athletes using oral contraceptives to alter their cycle for a big competition in the future. I have not done this personally so I can’t comment. However, I would highly recommend seeking out a doctor that is well-versed in this, if this is something you are considering. 

Angela Naeth is a partner at United Endurance Sports Coaching Academy (UESCA), a science-based endurance sports education company.

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ROAR: How to Match Your Food and Fitness to Your Unique Female Physiology for Optimum Performance, Great Health, and a Strong, Lean Body for Life by: Stacy Sims and Selene Yeager 

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About Rick Prince

Rick Prince is the founder of United Endurance Sports Coaching Academy (UESCA), a science-based endurance sports education company. UESCA educates and certifies running, ultrarunning, nutrition, cycling and triathlon coaches worldwide on a 100% online platform.

Categories:Cycling, Running, Strength Training, Triathlon


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