How Exercise Affects Your Menstruation Cycle

September 29, 2020
By Sabina Rebis

As tough as it may be to play soccer with your frenemy, aka your period, it’s about time to play nice. A regular cycle means your biological clock is synchronized, your bones are not depleted of their density, and you have enough energy to potentially carry another human being in your uterus.

Hardcore workouts can take a toll on your menstrual cycle. Why? Because often when the soccer season intensifies there is an energy mismatch in how much you are burning and how much you’re taking in. In times of high demand, the body adapts to a low energy availability status as daily workouts take a bite out of your calorie tally. Many athletes lose their period when the season gets intense exactly because of this energy deficit.

Energy is shunted away from bodily functions that are not required, such as ovulating and maintaining fertility, to ones of survival mode. Periods may become lighter or sometimes disappear completely. When this energy deficit occurs, the hypothalamus, the part of the brain responsible for hormone release that leads to the cascade of events culminating in a period, slows or stops the release of ovulatory hormones.

According to research, reducing calories by 500-800 per day, or keeping your intake the same while creating that same numerical daily deficit through exercise, is enough to disturb a menstrual cycle over the period of three months.

The loss of your period also means you have less durable bone tissue. In a study, ladies with low energy availability who trained hard enough to lose their cycle were much more likely to subsequently sustain a bone stress injury.

On the flip side, upping calories appropriately while increasing your training hours and so exercise level can actually result in better tolerance of monthly cramps. Women have actually been found to have fewer painful cramps when exercising regularly.