What to Do if You Lose Your Menstrual Cycle from Running

Secondary amenorrhea in athletes can have profound health effects. Here's why it happens and what to do about it now.

I’ve been training hard for a few years for half and full marathons and have stepped it up in the last year to 60-70 miles per week. What effect will losing my cycle have on my health? I haven’t had it for over nine months now, and though I want to continue to train, I also worry about what that is doing to my body. I’m 25, I eat well (a low-fat diet of around 1800 calories per day), and weigh 130 at 5’5”.  I’m also not on any hormones, medications, or the pill. How can I train better to regain my cycle, and why do you think I lost it to begin with? Thanks!  ~Lori

Lori, you are very wise to evaluate your training plan, as the loss of your cycle can have a profound effect on your health in the long term. When you go from having a normal cycle to a missed cycle for more than six months, it is considered secondary amenorrhea

Although this can be caused by a variety of issues, including medications, pregnancy, menopause, PCOS, stress, and hyperthyroid; in athletes, it is commonly a side effect of a combination of under-fueling and the demands of high volume, high-intensity exercise regimens. 

It’s always wise to start with a proper diagnosis, and I recommend seeing a doctor (integrative) that will look at your whole picture and evaluate why this is happening. It is common for the medical community to only prescribe “the pill” to reactivate your cycle, but without an understanding of why it's happening and the  proper balance of your lifestyle, merely taking a pill to solve the problem can put you at greater risk for further bone loss and hormonal issues later in life. 

Why does my cycle stop?

Again, assuming this isn’t related to the other factors mentioned above, when there isn’t enough fuel (energy) in your body, it begins to prioritize functions that are vital for survival. It will shut down the menstrual cycle in the absence of adequate nutrition, and in doing so, creates a hormonal stress response which results in low levels of the hormone estrogen, which is vital for healthy cycling (this is why the estrogen pill is often prescribed as a quick fix). 

With endurance athletes, it is common to get into a pattern of under-fueling in terms of calories and nutrition based on the metabolic expenditure, especially in female runners who are trying to lose or maintain a certain weight. 

Kelly Austin, a naturopathic doctor who specializes in athletic nutrition, recommends that women who have secondary amenorrhea need to eat enough calories to sustain a healthy menstrual cycle plus additional activity. Her recommendation is to consume 30Kcal/ kilogram of body weight. For instance, a 120-pound female would need 1600 calories per day just to live, breathe, and have a cycle. If she burned an additional thousand calories, her caloric intake would grow to 2,600 per day. 

When you combine under-fueling with the demands of a strenuous running program, it causes a deficit and drain in your body. If this goes on for extended periods of time with multiple training seasons without rest phases, it can result in a loss of your cycle due to hormonal imbalance and the stress response. This can also be the case for male runners, only the effect lowers their testosterone levels.

How will this affect my running performance?

Initially you may not feel anything at all, but that doesn’t mean it isn’t affecting you physiologically. Because low estrogen levels affect bone loss, stress fractures are often the first sign or symptom of the problem at hand. If the athlete continues to train under the systemic energy drain (not eating enough and exercising a lot), it will also affect your recovery rate, energy levels, and eventually your running performance.   

How can I reactivate my cycle?

Depending on how long the cycle is absent, it can take up to a few months to over a year to stabilize your body’s system and regain a normal cycle again.  The good news is there are many things you can do right now to begin to make this happen. 

  • The first step is to set a new training goal to establish a healthy cycle. It can be helpful to think of it as a new goal, rather than not training for a race.
  • The next step is to gain an understanding of your energy consumption versus expenditure. You can do so with a fuel log on paper or kept digitally--this is purely for awareness, not to develop a new habit of counting calories.
  • Invest in a thorough recovery season, where you focus on shorter run or cardio workouts for 30 minutes total, strength training-yoga-Pilates (not high intensity), and easy-effort movement like walking. It’s best to limit your cardio to three times per week (plus strength and walking) for 30-35 minutes, but you can include high-intensity intervals for these sessions (ie. Wup 5 min, 8x30-second sprint with 3-min. recovery.
  • Include low-impact activities like cycling or elliptical for your three cardio sessions for the week--this is especially good for those that have or are recovering from a stress fracture.
  • Begin to consume enough calories for your life plus your activities. This may mean eating more than you do normally, but once you start to feel better, it will become easier to do so. 
  • If your diet has been focused on a low-fat or nonfat menu, start to add healthy ingredients that will provide the much needed fat like avocado, olive oil, coconut oil, eggs with the yoke, 2% dairy, and meat. Remember eating fat doesn't make you fat--it is an energy source that is needed for healthy hormonal balance.
  • Some doctors may choose to prescribe hormones (bio-identical or the pill) to reactivate your cycle and reduce some of the negative side effects like insomnia. This can be an effective way to go if it is in combination with a recovery training plan. 

    This may not seem like a lot of fun if you’re in the heart of a training season now; however, at some point it is vital to regain your cycle so you can train from a healthy foundation. Once you have your cycle again, there are ways you can continue to train to reach your goals. Just changing your diet to include enough energy to fuel your life and running performance will aid in maintaining your cycle during a training season.

    Also, there are additional ways to structure your training regimen to avoid creating a deficit, as well. They include modifying your long run schedule, including strength training, balancing the intensity and volume by investing in a recovery season at least twice a year. 

    The great news is that you’re aware of the imbalance and are ready to make the changes to regain your flow so you can continue to rock it in life. Thank you for sharing your story.

    Happy trails.

    Download my free training plans here (5K, 10K, Half and full Marathon).
    Tweet me  @coachjenny

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