Performance nutrition during the menstrual cycle
As a woman, athlete and sports nutritionist, it's not only important for me to understand my own nutrition and performance during the menstrual cycle, but also the science-based research around this topic in order for me to apply it within my professional practice.
As women, we tend to know when we're 'due on'. We're a little bit moodier, want to eat everything in site and generally feel a bit 'bleurgh'. Although, that might just be me!
What actually happens throughout our 28-day cycle?
We have two 'phases' that we go through: the follicular phase and the luteal phase. The follicular phase is the first 15 days of our cycle, including the period, and the luteal phase is the second half, if you like - from day 16 to 28.
- days 1 - 7 - period
- days 8-13 - mid-follicular phase
- days 14-15 - ovulation
- days 16-28 - luteal phase
What impact does the menstrual cycle have in terms of nutrition and training/performance?
Each phase varies in the hormone balance, which can determine what type of fuel we use for exercise (carbs versus fats).
During the first phase (the follicular phase), we are more estrogen-dominant and, as such, adapt better to our training. Studies have shown that strength training has a greater effect during this phase, and on type two muscle fibre diameters (muscle growth).
During this phase, we tend to conserve glycogen stores (carbohydrate stores) but have an increased ability to burn fat. So, our bodies need more carbohydrate during this phase. Your diet should, therefore, be high in carbohydrates with regular intake of proteins. You also need to ensure your iron levels are increased during this phase to make up for the loss during the period and, to help absorb that extra iron, an increase in vitamin C is advised.
Great foods during this phase:
- kidney beans
During the second phase (the luteal phase), we are more progesterone-dominant. This is typically when the hunger levels increase but, with that, our metabolic rate also increases (which is good news for burning more calories). Studies have found energy expenditure can increase anything from 2-11% during this phase.
Due to the change in hormones, our bodies switch to being more fat-dominant as a fuel source during this phase. So, your diet should consist of healthy fats, regular intakes of protein and less starchy carbohydrates. The switch in fat/carbohydrate ratio will also help to increase the calorie intake.
Great foods during this phase:
- almonds, walnuts, cashews - in fact, any nuts!
- cacao nibs
My advice would, therefore, be to try and adjust your nutrition around your cycle and monitor how much of a difference it makes. If you're using a coach or personal trainer who writes you a program for your sport, try and periodise your training around your cycle, too!
For more information, visit the sports nutrition page. Or, if you’d like to know more about women’s nutrition, there are dedicated fact sheets about pregnancy and preconception, PCOS, PMS as well as the menopause.