Did you know that your nutritional needs change during your menstrual cycle? Female hormone levels vary during the menstrual cycle and can affect everything from exercise performance, substrate utilization, metabolic demand and nutrient requirements. And while you can’t always plan when you have an important competition or game, you can adjust your nutritional strategies to optimize performance based on hormonal fluctuations.
In this article, we discuss the hormonal fluctuations during a typical cycle, how these fluctuations can affect an athlete’s needs, and some tips on how to adjust to different phases of your cycle.
How do your hormones change during your cycle?
Hormones fluctuate throughout the month depending on the phase of the menstrual cycle. A typical cycle lasts an average of 28 days, but can range from 21 to 45 days. Cycles have two distinct phases, the follicular phase (day 1-14) and the luteal phase (day 15-28).
The follicular phase is when menstruation occurs. hormone levels (estrogen, luteinizing hormone (LH), progesterone, follicle-stimulating hormone (FSH)) are at their lowest point at the beginning of the follicular stage. Estrogen and FSH begin to rise around day 4 or 5 of this phase to prepare the body for ovulation. At the end of the follicular phase, LH surges due to the rise in estrogen and ovulation occurs. Then the luteal phase begins and these hormones begin to decrease.
Do calorie and macronutrient needs change during your cycle?
Consuming adequate calories and macronutrients is essential for athletes to have the necessary energy to perform, but also to support proper hormone function. Resting energy expenditure increases from 2-11.5% during the luteal phase (second half of your cycle). This could explain why an athlete may feel hungrier towards the end of their cycle. We always recommend that athletes listen to their bodies and this could be a good opportunity to add one well balanced snack all day long.
Macronutrients
Carbohydrates throughout your menstrual cycle
Depending on the phase of your cycle, substrate utilization (meaning which macronutrient your body uses most for fuel) and nutrient needs may change. Carbohydrate oxidation (using carbohydrates for energy) increases during the follicular phase, while glycogen storage decreases. Because of this, the follicular phase may better support intense exercise, but female athletes should prioritize carbohydrate consumption before exercise to ensure they have sufficient energy to perform.
The importance of adequate fat for menstruation
Eating adequate dietary fat is essential to support hormone production. Fat also acts as an energy source for low-intensity exercise. Due to the decline in estrogen during the luteal phase, carbohydrate oxidation is reduced and the body relies more on fat oxidation, which can better support low-intensity exercise. Athletes should aim to consume at least 20% of their total daily calories from fat and prioritize sources such as avocados, nuts, seeds, olives, oils such as avocado and olive oil, and fatty fish. Eating less than this amount could lead to deficiencies in essential fatty acids and fat-soluble vitamins such as vitamin A, D, E and K, and increase the risk low energy availability and menstrual dysfunction.
Protein throughout your cycle
Protein has many important roles in the body, including building and repairing lean muscle mass, supporting bone health, and synthesizing hormones, enzymes, and antibodies. Progesterone and estrogen levels peak during the mid-luteal phase (days 20-24). During this period, protein oxidation increases and plasma amino acid concentration decreases, so increased protein intake during this period may be beneficial. Female athletes should aim for 1.6 g/kg (.73 g/lb.) of protein per day. For a female athlete weighing 170 kg, this would be 124 grams of protein per day. We recommend that athletes consume protein consistently throughout the day, including a protein source at every meal and snack.
Do you need supplements during your cycle?
Certain nutrient needs increase during menstruation, and deficiencies in micronutrients (vitamins and minerals) can negatively impact overall health, athletic performance, and increase the risk of injury for athletes. Female athletes are often deficient in folate, riboflavin, vitamin B12, vitamin D and iron.
Creatine, omega-3 fatty acids, protein, and caffeine are all supplements that have been shown to be safe and effective in female athletes. We always recommend focusing on consuming these nutrients from food first as much as possible and then supplementing as needed.
Specific caloric, macronutrient, and supplement needs should be individualized to the athlete, but the recommendations outlined in this article is probably a universal starting point. If you’re interested in a personalized nutrition plan to meet your needs and goals, head over to our contact page apply for nutritional guidance.
