By: Lauren MacLeod, RD

(Note: In this blog post, we use the term “female” to denote an individual who is biologically female by birth and undergoes menstruation. It is not an assumption of gender identity.)

Relatively little research has been done on how female hormones impact training and nutrition, however this area is rapidly growing. The Journal of the International Society of Sports Nutrition recently published a review (a collection of research) that explains just how much female hormone levels can impact performance, nutrient use, and metabolic needs for athletes.

As a brief refresher, the primary female sex hormones are estrogen and progesterone. Estrogen impacts both the menstrual cycle and secondary sex characteristics (puberty, breast size, etc), while progesterone impacts the menstrual cycle. These two hormones fluctuate during the menstrual cycle, stimulating different phases. You can optimize your nutrition to align with these hormonal fluctuations.

Here are some important metabolic basics to understand before we dive into a deeper discussion about nutrition and menstruation. I’ll focus on the macronutrients (carbohydrate, protein, fat):

 Calories:

• Need to meet estimated calorie needs for proper hormone function and performance

Carbohydrates:

• Glycogen is your body’s storage form of carbohydrate. This is the well that your body draws on to support training.

• Increasing exercise intensity means increasing reliance on carbohydrates for energy.

Fat:

• Fat plays an important role in hormone production and function. You need about 20-35% of your calories from fat to meet these needs.

Protein

• Minimum 1.6g/kg per day for strength and endurance athletes

Now that we’ve reviewed the basics of menstrual hormones and sports nutrition. Let’s put the concepts together, moving through each phase of the menstrual cycle.

Follicular phase (day 1-14, starting with the first day of menstruation until ovulation):

Increased:

• Carbohydrate oxidation

Decreased:

• Protein oxidation

• Fat oxidation

• Glycogen storage

Nutrition takeaway:

• Emphasize carbohydrate intake

• Supports higher intensity exercise (increased intensity=increased reliance on carbohydrates for energy)

• Less efficient glycogen storages: make sure you are consuming enough carbohydrates before training

• Carb loading may be more effective during this phase

Luteal phase (day 15-28, from post-ovulation until premenstrual phase):

Increased:

• Fat and protein oxidation

• Glycogen storage

• Resting energy expenditure (you may be using 2.5-11.5% more calories)

Decreased 

• Carbohydrate oxidation

Nutrition takeaway:

• Emphasize protein and fat intake

• Balance carbohydrate and protein to balance blood sugar and promote adequate recovery

• Focus on endurance training, vs high intensity

Special note on the premenstrual phase: 

During the premenstrual phase, nourish for comfort vs performance. It can be more difficult to maintain blood sugar, so make sure you are getting enough carbohydrates to manage PMS symptoms.

In this post, I focused on overall calorie intake, carbohydrates, proteins, and fats. Want to dive deeper into vitamins, minerals, and hydration? Look out for our webinar series on athletes and menstruation, coming soon!

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Remember that everyone’s needs are individualized and this post is meant to provide a starting point.

References:

Bandyopadhyay A, Dalui R. Endurance capacity and cardiorespiratory responses in sedentary females during different phases of menstrual cycle. Kathmandu Univ Med J (KUMJ). 2012 Oct-Dec;10(40):25-9. doi: 10.3126/kumj.v10i4.10990. PMID: 23575048.

Campbell SE, Angus DJ, Febbraio MA. Glucose kinetics and exercise performance during phases of the menstrual cycle: effect of glucose ingestion. Am J Physiol Endocrinol Metab. 2001 Oct;281(4):E817-25. doi: 10.1152/ajpendo.2001.281.4.E817. PMID: 11551860.

De Jonge, X.A.K.J. Effects of the Menstrual Cycle on Exercise Performance. Sports Med 33, 833–851 (2003). https://doi.org/10.2165/00007256-200333110-00004

McGregor, R. Training Food 2015. Nourish Books

Wohlgemuth, K.J., Arieta, L.R., Brewer, G.J. et al. Sex differences and considerations for female specific nutritional strategies: a narrative review. J Int Soc Sports Nutr 18, 27 (2021). https://doi.org/10.1186/s12970-021-00422-8