Thankfully, it is becoming more well known that a missing period is a serious problem and not a marker of being “fit,” or a normal response to training.  Rather, periods are a health indicator with some health practitioners even considering them the “fifth vital sign.” While the importance of a period is becoming more widely known, what to do when you don’t have a period is not often discussed. That’s what I’ll be covering today, but before I dig into this topic, let’s start with some definitions. A missing period is called “amenorrhea.” There are numerous causes of amenorrhea. I will be discussing the amenorrhea caused by undereating and overexercising known as “functional hypothalamic amenorrhea.” Functional hypothalamic amenorrhea can be primary, which is when a female over 15 years has never had a period, or secondary, which is when a female who has previously had a period stops getting their period. One final note, if you are on birth control pills, this is not the same as a period. Birth control pills cause a withdrawal bleed every month regardless of whether you have amenorrhea or not. As a result, if you are taking birth control pills, you can’t know if you have a missing period. Now that we have some definitions behind us, I’ll highlight some steps you can take if you have a missing period.

Step one- see your medical doctor (if possible, one with training in sports medicine). As I mentioned, amenorrhea can have numerous causes. Functional hypothalamic amenorrhea is a diagnosis of exclusion. This means your doctor will need to run some tests such as lab work and an ultrasound to make sure that the amenorrhea isn’t being caused by a medical condition, such as thyroid issues or polycystic ovarian syndrome. However, an athlete’s lifestyle will probably give some clues as to the underlying cause of amenorrhea, such as diet and exercise, which I’ll discuss more below.  

If your medical doctor says that it’s normal to have a missing period because you’re an athlete and/or suggests taking birth control pills to address this missing period, seek help elsewhere. Healthy athletes get their period even when training hard and taking birth control pills doesn’t prevent the health outcomes that are caused by missing periods. While the medical field has thankfully become more aware of this, some health care practitioners continue to think that an athlete not having a period is “normal.” Depending on the openness of the doctor, this may also be an opportunity for them to learn more about the importance of regular periods in athletes. However, if they’re not willing to budge, try another doctor.

In order to regain your period, you should take a good look at your lifestyle for clues as to the underlying cause of the missing period. Working with a registered dietitian can be helpful to pinpoint areas that may need to be addressed. This is important because everyone is different, and there is no one size fits all approach to treatment. However, here are some common errors and some questions that you can ask yourself:

  • Have you recently lost weight or are you trying to lose weight?

Exercise itself does not cause a period to go missing, but rather, it’s due to not eating enough calories to cover the calories expended by exercise. For some athletes, this may result in an initial weight loss that coincides with a lost period. However, it is important to note that even if you are at a healthy weight or your body weight hasn’t changed, you can still have a missing period due to undereating and overexercising.  This is because a missing period is a sign that the body is trying to conserve energy due to inadequate calorie consumption. As a result, body weight can be stable despite undereating. Most athletes will have to gain weight for their periods to return. Usually, this is around the weight they were at before their period stopped.

  • Are you relying on your “hunger cues?”

If an athlete is only eating when they feel hungry, they are likely undereating. This is because exercise causes the release of hormones that suppress hunger. As a result, even if an athlete has expended a significant amount of calories due to hard training, they may not feel like eating. In order to eat enough calories to support training demands, most athletes will need to eat mechanically and because they know that they need to, rather than because they feel hungry.  If an athlete eats only when they are hungry, they will likely not eat enough calories on the days when they need the most.

  • Do you eat enough before, during, and after exercise?

Many athletes fail to eat enough calories in the time period surrounding exercise. This means that they’re spending more time in a calorie deficit even if they eat enough later in the day. An example is going for a training session first thing in the morning (after an overnight fast) with only eating a small amount or nothing beforehand. In this situation, an athlete is not only starting exercise in a calorie deficit state, but also pushing themselves into a further calorie deficit throughout exercise. This prolonged time in a calorie deficit can make it more likely that an athlete loses her period. To prevent this, athletes should aim to start exercise in a well fuelled state and refuel immediately after exercise. For many endurance athletes, who exercise for prolonged periods of time, fuelling during exercise also becomes important to minimize this calorie deficit.

  • Do you go long spans throughout the day with food?

This builds off the point above and the importance of minimizing the amount of time throughout the day spent in a calorie deficit. For busy athletes who are juggling the demands of training with other commitments such as school or work, it’s easy to go for long times without eating meals or snacks. Often this means “catch-up hunger” at the end of the day when there is finally sometime to eat. However, by this point, an athlete will have spent most of the day in a calorie deficit, which as I mentioned, can make it more likely that a period goes missing. To avoid this, athletes should be aiming to eat something every 3-5 hours. This means not only 3 meals a day, but also frequent snacks throughout the day.

  • Are you eating enough carbs?

Many endurance athletes are undereating because they are not eating enough carbohydrates. Carbohydrates are the primary fuel used for training and competition. Endurance athletes are constantly depleting their body stores of carbohydrates. Eating enough carbohydrates is important to replenish these stores, and to avoid decreases in blood sugar that can increase the likelihood of a missing period. Athletes need to eat a lot of carbohydrates, and most athletes that I have worked with are not eating enough (I blame the carb-phobic culture that we live in). Don’t fall for the low carbohydrate trap. Make sure that meals and snacks are loaded with carbohydrate rich foods such as bread, rice, cereal, starchy vegetables, and fruits.  

  • Are you filling up on low calorie options?

A “healthy” diet for a non-athlete is most likely unhealthy for an athlete. While many non-athletes need to focus on eating more fruits and vegetables, this is not usually the case for athletes. A plate full of fruits and vegetables does provide a lot of important vitamins and minerals, but it’s likely going to cause an athlete to be too full to eat other foods that are just as important for health and performance. Athletes with high training demands will likely need to limit the vegetables and fruits at meals to about 25% and include high calorie options, such as nuts, seeds, avocado, cheese, and oils, so that calorie requirements are met.  

  • Be honest with yourself, are you struggling with disordered eating?

If you are constantly thinking about your weight and food, this should be a red flag. Food should only take up a small amount of your thoughts and time. If eating and thoughts of food are interfering with your ability to enjoy life, then you may be experiencing disordered eating. Disordered eating can affect anyone, regardless of age, body weight, and athletic ability. This should be taken seriously, and you don’t need to wait for a diagnosis in order to seek help. For more information on disordered eating, click here.

Periods are so important for health. If you are missing your period, then you should seek help in order to restore it. For many athletes, this will require assistance in order to make the necessary lifestyle changes. The sooner you reach out for help, the easier it will be to restore your health.

Categories: Megan Kuikman

Megan Kuikman

Hello! I’m Megan Kuikman. I’m a Registered Dietitian with specialized training in sports nutrition. My goal is to help athletes and active individuals achieve a healthy attitude towards health, training, and food. I empower athletes to fuel properly for training in order to restore their health and enhance performance. You can get in touch with me at:


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