Carbohydrate needs and the menstrual cycle

Curious about how your menstrual cycle may affect your carbohydrate needs?

Estrogen has the effect of increasing glycogen uptake and storage in the muscle and glycogen sparing and increased fat utilization during exercise.

So, when estrogen is low, your body should be able to utilize relatively more endogenous carbohydrate (stored glycogen) to fuel exercise. Practically, this means you really need to pay attention to carbohydrate loading and post-exercise carbohydrate recovery to ensure you have adequate glycogen stores, particularly when you have back-to-back training days.

When estrogen is higher, your body should be able to oxidize relatively more fat compared to endogenous carbohydrate (glycogen) during exercise. Does this mean that you should be on a lower carbohydrate diet during these phases? NO! Not if you are still attempting to complete training sessions that include some intensity. This means you may need to increase the amount of exogenous carbohydrate you are taking in just before and during your training sessions to support higher intensity work. Remember, when carbohydrate intake rates are higher than 60 g/h, you are better off taking in mixed glucose-fructose carbohydrate sources to allow your GI tract to effectively absorb the carbohydrate for oxidation. Taking in high rates of carbohydrate also requires practice!

Final point, not all women are the same so MC and fueling needs can differ between individuals. It’s a great idea to start tracking your menstrual cycle and make notes on how you are feeling during training and recovery, and then start adjusting fuel as needed.