The Athlete’s Guide to the Menstrual Cycle

Section 1: The Menstrual Cycle Explained

The menstrual cycle is a natural process that helps the body in individuals with a uterus prepare for a possible pregnancy. It usually lasts about 28 days, but it can range from 21 to 35 days depending on nutrition, stress, and training intensity. In the first few years after someone starts their period (menarche), their cycle may be irregular. However, this is normal. Regularity may come, for most people (not all), within a few years of time after the first period. During that time, periods may be longer—closer to 7 days—and will shorten with time. The cycle consists of four main phases: menstruation, the follicular phase, ovulation, and the luteal phase.

Menstrual health is really important to understand because it serves as a window into overall health, especially for teen athletes whose bodies are still developing. Learning to train with your body instead of against it is important in minimizing injuries and having a healthy career.

If you are missing periods, having intense pain, heavy bleeding, or any other concerns about your periods, you should bring those up with your doctor. If you are missing school, practice, or activities because of your period, that is also something important to share with your doctor. These are things medical professionals really want to know because they help assess your overall health and well-being.

To begin, menstruation marks the first phase of the cycle, lasting about 3 to 7 days. During this time, estrogen and progesterone levels drop, causing the uterus to shed its lining. This results in menstrual bleeding, which consists of blood, mucus, and tissue cells. While some people may experience symptoms such as cramping, mood swings, diarrhea, and fatigue, others might not notice any significant changes. With intense exercise and inadequate nutrition and recovery, this phase of the menstrual cycle may be missed, which can indicate certain health conditions that should be discussed with your doctor. Intense pain and extremely heavy bleeding are also not typical and should be brought up to a medical professional.

The next phase is called the follicular phase, which begins on the first day of menstruation and lasts until ovulation, meaning that it overlaps with menstruation. During this phase, the body starts preparing an egg for ovulation. A hormone called follicle-stimulating hormone (FSH) is released, signaling the ovaries to start maturing several follicles (tiny sacs that contain eggs). Typically, only one follicle will fully mature into an egg, which is the one that will be released during ovulation. The maturing follicle releases estrogen, which helps thicken the uterine lining in preparation for a possible pregnancy. As estrogen levels rise, energy levels tend to increase, making this, for some people, an optimal time for physical activity. Strength gains and endurance may feel easier during this time.

Ovulation occurs next, around day 15 of the cycle for a 28-day cycle. A surge in luteinizing hormone (LH) triggers the release of a mature egg from the ovary. Because the egg is now in the fallopian tube, where it can be fertilized, this is the most fertile time in the cycle. During ovulation, estrogen levels peak, which often results in higher energy and an overall sense of well-being.

Following ovulation, the luteal phase takes place, lasting from approximately day 15 to 28 for a 28-day cycle. If the egg is not fertilized, the body prepares to restart the cycle. Progesterone levels increase, causing the uterine lining to thicken further. Some people may experience premenstrual symptoms such as bloating, fatigue, and mood changes due to hormone fluctuations. This phase can also lead to a rise in body temperature, heart rate, and breathing rate, potentially making exercise feel more difficult. Since progesterone causes the body to retain fluid, hydration and electrolyte intake are especially important.

Section 2: How the Menstrual Cycle Affects Energy Levels, Training, and Competition

The menstrual cycle can impact energy levels, training, and athletic performance. Many athletes notice that they have more energy and recover faster during the follicular and ovulation phases. This is because of hormonal shifts—estrogen rises and progesterone remains low—which helps with oxygen uptake, muscle recovery, and energy levels. In contrast, the luteal phase can be characterized by a decrease in energy and an increase in fatigue. However, individual experiences vary drastically, and some athletes do not notice a significant difference in their performance throughout the cycle. With that said, it is important to prioritize recovery and well-being during all phases of your menstrual cycle, especially during phases when symptoms are most intense.

Understanding how exercise affects the menstrual cycle is key to staying healthy while working toward athletic goals. Exercise can help regulate symptoms of the menstrual cycle. It can ease physical discomforts such as cramps and bloating, while also helping stabilize mood and reduce irritability. Exercise boosts endorphin levels and improves circulation, thus reducing stress.

While exercise offers numerous benefits, it is essential to properly work alongside your cycle by planning specific-intensity workouts and recovery days to match your hormonal fluctuations. Exercise, especially when prolonged or intense, can result in the release of stress hormones such as cortisol and adrenaline, which can lead to irregular periods, low bone density, or even amenorrhea. Some professional athletes have experienced disruptions in their menstrual cycles due to intense training and inadequate recovery. Olympic runner Mary Cain spoke openly about how extreme training and poor nutritional support led to irregular periods and stress fractures, ultimately impacting her performance and long-term health. She stated, “I was emotionally and physically abused by a system designed by Alberto and endorsed by Nike.” (The New York Times video op-ed, 2019.) In this video, Cain described how the coaching staff's relentless focus on weight loss led to severe health consequences, including broken bones and loss of her menstrual cycle.

However, many athletes have successfully adapted their training routines to align with their menstrual cycles, demonstrating the importance of personalized exercise strategies. Athletes like Serena Williams, a legendary tennis player, and Paula Radcliffe, a world-renowned marathon runner, have emphasized how adjusting workout intensity and incorporating proper recovery helped maintain hormonal balance while optimizing performance. Megan Rapinoe, a professional soccer player, has discussed tracking her cycle to better manage symptoms like fatigue and cramps. She advises planning lighter workouts during low-energy phases and focusing on high-intensity training during peak-energy periods for consistent performance.

Section 4: Tailoring Workouts to Different Phases of Your Cycle

It’s important to tailor, track, and continually tweak workouts in alignment with the phases of the menstrual cycle to help maximize performance and support overall well-being. Being strategic in your workout planning not only enhances fitness but also contributes to long-term health and resilience.

However, it's essential to remember that the phases and symptoms often associated with the menstrual cycle are general guidelines; everyone’s experience is different. That’s why tracking your cycle and symptoms is crucial. It allows you to better understand your unique patterns and adapt your training in a way that truly supports how your body works best.

Tracking menstrual cycles is important for athletic performance. Apps like Clue, Flo, FitrWoman, Glow, and Wild.AI help individuals monitor energy fluctuations, symptoms, and recovery needs, helping them customize training plans accordingly. Keeping a fitness journal can also be beneficial for noting patterns in endurance, strength, and recovery across different phases.

Menstruation: Since estrogen levels are at their lowest, restorative exercises like yoga, walks, and low-impact cycling can alleviate cramps and promote relaxation without overexertion.
Follicular Phase: This phase should be used to stretch performance limits with challenging workouts like high-intensity interval training (HIIT), strength exercises, or endurance runs.
Ovulation: This phase is ideal for competitive events due to peak energy levels and strength. It's important to recognize that peak performance can occur at any point in the menstrual cycle, and many athletes achieve their best results regardless of timing. However, heightened estrogen levels during certain phases can affect joint stability by increasing ligament laxity, which may elevate the risk of injury. Being aware of these physiological changes can help with training and injury prevention.
Luteal Phase: This phase is best for moderate-intensity workouts, steady-state cardio, flexibility exercises, and stretching.

Section 5: Managing Period Symptoms: Cramps, Fatigue, and Mood

It is important to manage period symptoms to train effectively and continuously strive for excellence.

Cramps: Gentle exercises like walking and cycling can help reduce cramps by improving circulation. Heat therapy, such as a heating pad or hot-water bottle, and anti-inflammatory foods rich in omega-3 fatty acids also help. Adequate sleep and hydration are equally important. Meditation, deep breathing, and relaxation techniques can be easily integrated into your schedule with just ten minutes in the morning or evening to help manage stress and reduce the intensity of cramps. If cramps are severe or cause vomiting, talk with your doctor about medical options.

Fatigue: Manage fatigue by engaging in moderate-intensity exercises and avoiding overtraining. Get adequate rest, stay hydrated, and practice relaxation techniques.

Mood Swings: Exercise releases endorphins, which naturally boost mood. Meditation, yoga, and other mindfulness practices also support emotional health. Hormonal birth control may help stabilize mood fluctuations for some individuals by regulating hormone levels, though it should always be considered in consultation with a healthcare provider.

Section 6: Menstrual Products

Different menstrual products can help manage periods during physical activity, though preferences are highly personal. Pads are easy to use and comfortable but may shift during high-intensity exercise. Tampons stay in place and are suitable for swimming but must be changed every 4 to 8 hours to prevent infection. It is super important not to forget to change your tampon. Menstrual cups are ideal for long-duration activities since they can be worn for up to 12 hours and hold more fluid than tampons. That said, they may be uncomfortable to use at first, especially when inserting or removing them. Period underwear provides comfort and absorbency for lighter-flow days but may not be the best choice for high-impact sports. You can pair period underwear or period swimwear with other menstrual products as another layer of protection on heavy-flow days.

Section 7: Athlete Stories

Although the topic of menstruation in athletics is often taboo, some top athletes have shared their experiences with managing their menstrual cycles while competing. Simone Biles, the three-time Olympic gymnast, has used birth control for many years to prevent her period during competitions, though this may not be an appropriate or safe method for high school athletes. Fu Yuanhui, the two-time Olympic swimmer, openly discussed how her period affected her energy and performance at the 2016 Olympics, helping to break the stigma around menstruation in sports. Dina Asher-Smith, the three-time Olympic runner, had to withdraw from a championship race due to calf cramps she believed were related to her period, possibly tied to a condition called dysmenorrhea. This led her to advocate for more research on how the menstrual cycle affects female athletes, something that has been under-researched for decades.

Peer Stories:

Ava, a junior cross-country runner, shared that she used to dread racing during her period because of cramps and low energy. Once she began tracking her cycle and talking openly with her coach, she started adjusting workouts and using heat patches before meets. “I stopped seeing my period as a setback and started planning around it.”
Leila, a swimmer, explained how she used period swimwear and a menstrual cup during competitions to feel more confident. “It took a little experimenting,” she said, “but now I never miss practice just because of my period.”