Don't Let Your Cycle Ruin Your Training. Period

As adventure women, we let few things slow us down: we bag peaks between the ebb and flow of stabbing abdominal pain, crush technical downs through lower back spasms and keep a casual face while our body temperature rises nearly three degrees and nausea overcomes us.

Although we are more than equipped to deal with the hassle, being a female trail runner requires more preparation and understanding of one’s physiology than just throwing some gels in a hydration vest and doing some leg swings before a run.

What do you do when you realize the race you’ve been training for falls squarely in the middle of your period? Are you training too hard or is it the lack of glycogen that’s making you fatigued?

It all breaks down to two cycles—learn and track them and you may just master training on your period.

Heck Yes vs What the Heck?

The two phases are the Follicular Phase, or days 1 to 14 of our cycle, with day one being the first day of our period, and the Luteal Phase, or days 15 to 28 of our cycle. After the actual days of menstruation, the Follicular Phase is our invincible, or “heck yes” phase, wherein our estrogen levels are low and consistent, and consequently, we feel strong, energetic and generally, unstoppable.

The Luteal Phase, in which we experience PMS, is our “what the heck” phase. During this phase, our hormone levels rise and fluctuate, leaving us feeling heavy, fatigued and generally annoyed that the run we crushed last week now feels nearly impossible.

Spending the days of our Luteal Phase crumpled in a pity puddle simply isn’t an option when there are mountains to climb. We can uncover the reality of what is happening in our bodies, instead of feeling cursed by Mother Nature.

Glycogen and Estrogen and Blood Volume, Oh My!

In the week leading to her period, a woman’s body begins sparing her glycogen in an attempt to compensate for the tidal wave of estrogen she is now producing. As a runner’s primary source of fuel, these readily available stores of sugar are key to maintaining consistent energy, so lack of supply can be problematic.

In addition to the increased estrogen (and corresponding lack of glycogen), a decrease in plasma volume hinders a woman’s ability to regulate her body temperature and manage lactic acid build up.

To combat the greater likelihood of hitting the wall due to reduced access to glycogen, a woman in this phase of her cycle should consider consuming greater amounts of carbohydrates packed with these energy-giving sugars per hour of exercise.

Like all other aspects of managing nutrition, each woman will respond differently to her increased carbohydrate intake and should experiment with what works best for her.

Generally, however, a woman exercising in her Luteal Phase should increase her baseline carbohydrate intake by about 25 to 50 percent.

After she begins menstruating and her hormone levels finally begin to freakin’ relax, she can start the process of gradually reducing her carbohydrate consumption back to her baseline amounts.

In addition to the increased estrogen (and corresponding lack of glycogen), a decrease in plasma volume hinders a woman’s ability to regulate her body temperature and manage lactic acid build up.

According to the Journal of Applied Physiology, in the days leading up to menstruation, a woman’s plasma volumes may decrease up to eight percent, resulting in thicker blood concentration. Plasma is the primary agent in promoting sweat production and assisting optimized muscular blood flow, so changes in its volume can have serious repercussions for a woman engaging in physical activity, especially in the extreme conditions in which trail runners thrive.

To avoid overheating and to promote the blood flow essential in circulation and recovery, a runner should be more conscious of taking in extra sodium and electrolyte-replenishing liquids during these “what the heck” days. Increasing these liquids will induce more regular rates of sweating, as well as enable blood to flush out the lactic acid build up that can hinder recovery. Blood volume is also increased with consistent training, prioritizing altitude when possible and heat training.

Test Your Sweat Loss

To establish the sweet spot when it comes to liquid consumption, a woman could perform a sweat-loss weight test during the different phases of her menstrual cycle. By learning how much water weight she loses post-workout in both the Luteal and Follicular phases, she can determine an appropriate percentage by which she should increase her electrolyte and sodium replenishing liquids on her “what the heck” days.

For example, if she loses three pounds of water weight after a trail-crushing session during her invincible, “heck yes” Follicular Phase, and only loses one and a half pounds in similar conditions on the same trails during her Luteal Phase, she should correct this discrepancy by doubling her typical fluid intake.

In considering managing the other, more general symptoms that occur when physically menstruating, like fatigue, cramping and bloating, all women, especially runners, can benefit from implementing caffeine (up to 500 milligrams per workout safely), and magnesium and calcium-rich foods into our diets. These additions will help regulate the hormonal imbalances that exacerbate negative period symptoms.

And although we may feel like we’ve got the short end of the applicator when it comes to menstruation, there are actually a few perks to being a female runner. The release of endorphins that accompany physical activity can act as a natural painkiller for cramping, and regular exercise often reduces the intensity of period symptoms.

Overall, as adventure women, we eat trails for breakfast, conquer mountains for lunch and capture vistas for dinner. If we stay informed, we certainly won’t let those “what the heck” days hinder our enjoyment of everything the great outdoors has to offer. Grab your carbs, your sodium-packed liquids, a few gal pals and hit the trails with confidence.

—Emily is a North Idaho-based freelance writer with an affinity for covering herself in mountain mud.