• Share this story:

I never imagined that our menstrual cycle affects so much until I started reading about it. And once I started reading, I realized how little I really knew about my own body. We just don’t really talk about “it”, right? Even though “it” (our monthly menstrual cycle, the rise and fall of hormones) plays a huge roll in how we feel and our athletic performance. So let’s fix that, and start the conversation!

First, let’s do a little review 

The average cycle is 28 days; day 1-14 is the follicular phase, and 15-28 is the luteal phase. The cycle begins on the first day of your period and ovulation is right around the middle. If you have a longer cycle, the follicular phase is what is longer, not the luteal phase. (This only applies to women who have a menstrual cycle, not those who are on the pill or don’t have a cycle.)

Let’s focus on two main hormones: estrogen (or estradiol) and progesterone. With the start of the follicular phase (the start of your period), these two hormones are at their lowest which means this is prime time to push your body for those strength or endurance gains.

The luteal phase

During this phase, estrogen and progesterone kick into high gear and progesterone actually surpasses estrogen levels. They both reach their peak about five days before menstruation. Hello, mood swings! If the egg is not fertilized the hormones fall and you are back to day one. Exercise feels harder during this high-hormone time. Estrogen and progesterone affect how fluid is regulated in your body. The reason you may feel bloated is because your body retains water (via an estrogen signaling pathway) and loses sodium retention (due to progesterone). It also constricts blood vessels which increases blood pressure, and that signals your plasma (the liquid portion of our blood) volume to drop. When plasma is low, our blood is thicker which means less blood is pumped out with each heartbeat. Progesterone elevates our core temperature with the lower volume of blood, and it is harder for you to sweat. Because you are shedding more sodium, you are also more likely to get heat stress. Make sure you start drinking water before you workout and increase your sodium intake.

During our luteal phase peak, high progesterone causes our muscles to breakdown at a higher rate during hard efforts and high estrogen slows the growth capacity. It is more difficult for us to make and maintain muscle at this time so it is important to take in protein (with some carbs) before and within 30 minutes after exercise. Do you get food cravings during this time? Your metabolism actually has a slight uptick a few days before your period. Estrogen reduces your ability to burn carbs but increases fat burning. This helps out endurance, but not high-intensity activity. You’ll need to add in a bit more carbs during this time especially if you are doing intense activity over 90 minutes.

Negative Symptoms Take You away from Exercise?

So what happens when cramping, nausea, headaches, GI issues, or lack of energy during your period stops you from exercise? You can actually do some preplanning to reduce these effects 5-7 days before your period by taking a little supplement “cocktail”:

• 300mg magnesium,
• 4g omega-3 fatty acids, and
• 80mg aspirin (it has to be aspirin!)

Menstrual headaches are usually caused when the hormones drop right before your period. You may have a sudden dilation and constriction of your blood vessels as your blood pressure changes. The best way to combat this is to stay hydrated and eat more foods rich in nitric oxide (e.g. beets, pomegranate, watermelon, spinach) to help promote dilation.

Another thing to watch out for is becoming anemic, especially if you have heavy periods. Exercising causes muscle stress and damage which increases your cortisol level (stress hormone). Your liver tackles that by pumping out hepcidin, which negatively affects iron absorption.

Remember, everyone is different and the hormones may affect you differently. But tracking your cycle and taking note on how you feel and how your body responds is paramount to giving your body the best platform for performance. Always listen to your body and remember that a positive attitude will make any phase better!

Most of this information came from the book Roar, by Dr. Stacy Sims, if you’re interested in getting into more detail. I’ve also read a variety of articles here on the world wide web. Just Google “Menstrual Cycle and Athletic Performance” and you’ll be down a rabbit hole of knowledge in no time! If you find any interesting tidbits, or just want to chat, I would LOVE that!