Cycle syncing for exercise

As women, we take our menstrual cycle for granted. In reality, it has a profound effect on your health, far more than I ever gave it credit for as a young female athlete.

Menstruation is a definitive marker of female health. It’s a vital sign (or should be). The hormones that that rise and fall on a cyclical pattern each month affect body temperature, breathing rates, hydration, blood sugar, bone health, fat oxidation, and tissue laxity to name a few. In this regard our female hormones play a vital role in training and recovery. Performance is not just about strength and speed. 

You may notice during certain times of the month you avoid exercise altogether or feel worse and more fatigued afterward. This varies from person to person because many other variables affect performance like nutrition, sleep, mindset, physiological health, and stress. All should be taken in to consideration when tracking your cycle with exercise.

More research needs to be done on this topic but according to the systematic review of studies by Kelly Lee McNulty, and Kirsty Jayne Elliott-Sale there is no need for mass guidelines as not everyone is identical in regard to their monthly cycle. Meaning, there is NO one size fits all method of exercising during your period, but tracking can give you a more personalized understanding of your body.

There may be a reason behind why you feel worse exercising during PMS or why you feel better. “More than half of elite female athletes report that hormonal fluctuations during their menstrual cycle negatively affect their exercise training and performance capacity.” Tracking your period in accordance with your exercise routine is a way to find out more about your body. It can give you a clue as to what days you may need more rest and recovery during the month.

The importance of menstruation

Many females have an irregular cycle (oligomenorrhea) or no cycle at all (amenorrhea). The hormones associated with menstruation are involved in nearly all body tissue including skeletal, cardiac, musculature, and digestive.  In order to understand the importance of a regular monthly cycle, let’s look at what happens when it gets disrupted.

Studies show that female runners with infrequent periods are 6x more likely to sustain a bone stress injury (stress fracture). Oligomenorrhea is a preliminary sign of someone being in an energy deficit. The body can turn off your period as a protective mechanism when it senses disruption. Female hormones, specifically Luteinizing hormones can decrease with just five days of low energy availability. Food is what provides that energy.

Mom’s if your teenage daughter is really athletic and not having her period don’t let someone normalize it. The period stops when the body is lacking available energy to function. This is called relative energy deficiency in sport. (RED-S)

Take a look at the health consequences that occur with amenorrhea.

One thing I definitely did not understand as a young female athlete was how important food was for a regular period. Food is your fuel to move well and to move continually day after day. Amenorrhea can be a sign your body is not getting enough energy through nutrition and it can effect performance drastically. “Research has shown that within 48 hours, without sufficient fuel, your body can shift from building muscle to breaking down muscle.” 

The earliest sign of acute performance decline is central fatigue. This is when an athlete feels the need to increase exertion for the same workload and has much more fatigue with poor recovery afterward. Performance equals training + recovery. Training is a healthy form of stress on the body but it must be followed by adequate rest in order to heal, grow, and make gains. 


Simple way to track your cycle

For a guide to understand what days to push hard and what days to recover, consider period tracking with your exercise routine.

  1. Pay attention to your body.
  2. Use a period tracker app like Fitrwoman , Flo, or Clue
  3. Use a regular old paper calendar for the free version
  4. Write down symptoms from days 1 to day 28 (a regular cycle can vary with days 21-35 still considered normal). Symptoms to jot down are mood, energy, anxiety, how your felt during exercise, how you felt the day after exercise, discomfort, stress, and PMS.
  5. Write down your exercise routine each day.
  6. Write down sleep difficulties.
  7. Note trends over a 3 month period of time.
  8. Be kind to yourself.

What the science says

Now that you’ve got an idea how to track, here’s what the science says regarding exercise and menstruation. First of all, your period is kind of your super power. Estrogen and Progesterone are vital to our health and performance as females. Women are better at recovering to max strength than men. Women can also engage in more frequent training than men. After menses, before ovulation may be the best time for muscle adaptation to occur with strength training and HIIT.

Birth Control

If your cycle is “regular” due to birth control, there is still something you need to know.  80% of females take oral contraceptives at some point in their lifetime. It’s important to know that oral contraceptives down-regulate the natural hormone levels. Studies in females who take oral contraceptives show a slightly inferior exercise performance when compared to those with a natural hormonal cycle. In part, this is due to the low level of natural hormones in the body. The synthetic hormone levels from birth control do not rise and fall as much as natural hormones. 

Follicular Phase

In the natural hormone cycle, exercise performance has shown  a trivial reduction in the early follicular phase when estrogen and progesterone are low (this is when menstruation starts). This is so trivial that it may only have an affect on elite athletes when the trivial amount actually matters for winning.  As far as training is concerned, researchers have noted a slightly higher gain in muscle strength during the late follicular phase when estrogen is high. However there is so much more research needed. 

Luteal Phase

Exercise may be more difficult during PMS – due to high hormonal levels. The elevated levels also affect blood sugar, breathing rates, and body temperature. During these high hormone levels (luteal phase) recovery after exercise may be more difficult. This is when it would be a great time to avoid overtraining. 

Right after menses, when estrogen is rising when there is an increase in joint laxity and a reduction in neuromuscular control. Studies also show that most female ACL tears happen the week after menses when estrogen is higher.

Author Christine Yu sums it up, “Helping women identify strategies to mitigate symptoms of abdominal cramps, headaches, breast pain, fatigue, and mood changes may have a more direct impact on fitness and performance than any phase-to-phase hormonal fluctuations.”


For those who have hit menopause and have no cycle, bone density declines by up to 20% in menopause. So it is of vital importance to add strength training into your exercise routine. Many menopausal women have a hard time recovering after exercise. The lack of hormones in the body have an affect on this. Estrogen aids in recovery. You can still exercise but may need shorter bouts than you are used to and longer recovery periods in between. If you find yourself getting injured frequently during peri-menopaue or menopause, listen to your body. Amanda Thebe does a great job explaining this season of life in her book, Menopocalyse

Personalized not Prescribed

Remember this is a personalized case by case basis, it is not necessary to get a whole team all on the same period/training schedule.  That would NOT be manageable. As well your training regimen does not need to be based exclusively around your menstrual cycle phases. There are numerous lifestyle and physiological factors that need to be considered before prescribing a training program. Tracking helps you learn about your unique physiology. While this is an emerging field of science, don’t neglect the underlying foundations of health like nutrition and sleep which play a much larger role in training and performance.

If you are a mother reading this who is worried about her daughter and RED-S, consult with your local dietician who works with female athletes. If you are a female athlete of any age who is struggling with persistent pain and injury and wants to get back to your sport or activity, contact me.

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