Fueling Considerations for Female Athletes

Maximizing performance and recovery through the menstrual cycle.

By Jennifer Kurtz, PhD, CISSN, CSCS, EP-C

Introduction

More than ever, there is a high prevalence of women participating in sports. That has warranted focused attention on the potential impact of menstrual hormones – specifically progesterone and estrogen – on exercise performance and metabolic demands.

Throughout the menstrual cycle, women have different caloric needs, substrate utilization (carbohydrates, protein, or fat), fatigability, body composition, performance, and recovery needs affected by the fluctuations of these hormones (Wohlgemuth et al., 2021). To maximize performance as a woman, it is essential to understand the role of these hormones on sports performance and nutritional needs.

There are different components of the menstrual cycle, each with varying nutritional demands and performance effects. Understanding when performance may be naturally increased or suppressed by the menstrual cycle may allow women to optimize their nutrition.

A regular cycle can range from 21 to 45 days and consists of two main phases: the follicular phase and the luteal phase (Wohlgemuth et al., 2021). 

In this blog, I’ll explain the nutritional considerations for each of the hormonal phases, helping athletes get the most out of themselves while ensuring their bodies have everything needed for performance, recovery, and general health.

Follicular Phase

The follicular phase can last ~14 days, and during this phase, progesterone, follicle-stimulating hormone, estrogen, estradiol, and luteinizing hormone are at their lowest. For the purposes of athletic performance, we’re focusing on those low estrogen levels, which can increase output by hamper recovery.

Estrogen is a master regulator of body composition and bioenergetics – which is just a fancy word for how our bodies can produce energy in the form of ATP.  When estrogen is low, it is easier to break down carbohydrates. Since carbohydrates are primarily used for high-intensity bouts, women can capitalize during follicular phase phase by lifting heavier weights and performing higher-intensity activities.

However, recovery rates during the follicular phase may be impeded by higher markers of inflammation and muscle damage. Therefore, it is important to consider nutritional recommendations during this phase to maximize performance and to minimize any impediment to recovery.

Nutritional Considerations for the Follicular Phase

The nutrient focus should be on vitamin B1, calcium, vitamin C, zinc, iron, and omega-3 fatty acids to lower inflammation and oxidative stress, improve recovery, and prepare the body for the release of an egg. (Please note: This does not mean not consuming other essential micronutrients, such as Vitamin D.)

Here, I will highlight a few of these vitamins and minerals:

• Zinc assists with hormone release, maintaining homeostasis and redox balance, proper functioning of cells, immunity, and synthesis of proteins (Nasia et al., 2020). It can be found in legumes, eggs, almonds, beef. 
• Calcium assists with muscle contraction and relaxation and bone mineral density (Wohlgemuth et al., 2021). It can be found in dairy, edamame, almonds, etc. – sources are many and varied.
• Omega-3 plays a role in reducing inflammation, improving immune function and growth and development (Wohlgemuth et al., 2021).
• Iron produces red blood cells and helps transport oxygen. Further, iron is essential for optimal brain function, energy, and immune function.
• Vitamin B1, found in whole grains, meat, and fish, plays a role in carbohydrate metabolism and may reduce symptoms of performance fatigue (Abdollahifard, Koshkaki, & Moazamiyanfar, 2014).
• Vitamin C helps promote the follicular phase by raising estrogen while simultaneously lowering progesterone levels. 

It may also be advantageous for women to consume pre-exercise carbohydrates when carbohydrate breakdown is higher in this phase (Wohlgemuth et al., 2021). The highest capacity to restore glycogen also occurs in this phase, so women should focus on rapid replenishment of 0.75 g/kg following prolonged exercise to restore spent muscle glycogen and decrease the recovery period (Wohlgemuth et al., 2021).

Ovulation 

Nutritional Considerations for Ovulation

Ovulation (bleeding) starts day ~11-13, and this is when the luteinizing hormone spikes. The nutritional focus during this time should be hydration, fiber, gut support, folic acid, vitamin E, vitamin D, omega-3 and omega-6, and selenium to aid in the removal of estrogen.

Fiber-rich foods include dark green leafy vegetables such as broccoli, Brussels sprouts, asparagus, and spinach. Other foods should include whole-grains, nuts, legumes, and antioxidants such as blueberries, strawberries, raspberries, and coconut.

The addition of prebiotics and probiotics is also recommended to support gut health. Prebiotics can be found in whole grains, bananas, green onions, garlic, soybeans, and artichokes; probiotics can be found in fermented foods like kombucha, yogurt, and sauerkraut. 

The Luteal Phase

Following ovulation, the luteal phase starts (day ~14). During this phase, luteinizing hormone and follicular stimulating hormone return to close to baseline levels. However, progesterone and estrogen rise around day 20-24 (mid-luteal phase) and then fall.

After ovulation, there is a shift in fuel sources. Your body relies more on blood glucose and cannot access liver and muscle glycogen as well, because estrogen and progesterone reduce the ability to break down carbohydrates.

During the luteal phase, women should increase carbohydrate consumption to support higher glycogen levels, adhering to g/kg recommendations: 8-10 g/kg BW of carbs in the three days leading up to an event and at least 2 g/kg BW four hours prior to the event (Wohlgemuth et al., 2021).

The luteal phase benefits endurance performance, because when progesterone and estrogen are higher, muscle glycogen (stored carbohydrates) is spared. That makes endurance training optimal, but it may also reduce performance at higher intensities or activities like sprinting or threshold training. 

There is also an increase in core temperature and cardiovascular strain, reliance on fats, and protein breakdown, which is accompanied by greater energy expenditure and possibly appetite (Wohlgemuth et al., 2021).

Nutritional Considerations for the Luteal Phase

During this phase, women often feel hungrier due to the increase in metabolism. The nutritional focus of this phase should include nutrient-dense, nourishing foods; protein with each meal; and dense snacks.

The luteal phase is marked by an increase in protein breakdown (Wohlgemuth et al., 2021). Female athletes should consume ~1.6g/kg/day, emphasizing essential amino acids (EAA), branched-chain amino acids, and more lysine to support muscle protein synthesis (MPS) to ensure muscle mass is maintained (Wohlgemuth et al., 2021). Muscle protein synthesis is maximized when protein is consumed through intermittent feeding, ~20-30 g every 3-4 hours (Wohlgemuth et al., 2021).

Here are sources and highlights for key nutrients:

• Essential amino acids are critical and can include foods such as beef, poultry, fish, eggs, dairy, soy, quinoa, and buckwheat. Consuming 6-12 g of EAA alone or as part of a protein supplement of 20-40 g can stimulate MPS. 
• Magnesium supports energy production. Magnesium-rich foods include chicken, pumpkin seeds, quinoa, dark chocolate, and legumes.
• Vitamin B6 also supports energy production, and is found in fish, meats, legumes, and starchy carbohydrates such as pumpkin, sweet potato, and apples.

Figure 1. The physiological implications and metabolic adaptations of estrogen and progesterone during a menstrual cycle. (Wohlgemuth et al., 2021)

Other Nutritional Considerations

Found in fish, orange juice, milk, egg yolks, etc., vitamin D is shown to have a positive effect on alleviating menstrual pain and reducing the severity of dysmenorrhea (severe cramps) (Amzajerdi, Keshavarz, Ghorbali, Pezaro, & Sarvi, 2023). Further, there is also evidence that vitamin D can regulate the course of the menstrual cycle. 

One final consideration goes beyond the cycle to encompass daily nutrition, regardless of hormones. Most women under-consume calories, particularly carbohydrates (Wohlgemuth et al., 2021). This puts female-athletes at risk of developing low energy availability (EA), which can be calculated by energy intake minus energy expenditure per day.

An EA of approximately 40-45 kcal/kg fat-free mass/day is optimal for maintaining normal fluctuations in hormones, body mass, and performance (Holtzman & Ackerman, 2021). However, many women fall in the <30 kcal/kg FFM/day range.

Put plainly, EA is the remaining energy available that can be used for physiological functions (e.g., maintaining homeostasis, thermoregulation, protein building, etc.) (Holtzman & Ackerman, 2021). Failure to reach sufficient metabolic and calorie demands can lead to disruptions in the menstrual cycle, performance determinants, fatiguability, reduction of carbohydrate usage, decreased bone mass, disordered eating, amenorrhea, and potentially lead to a risk for injury and osteoporosis (Wohlgemuth et al., 2021).

Disordered eating can lead to energy imbalances and can result in amenorrhea, the absence of a menstrual cycle. Lack of proper nutrition may lead to two possible conditions: Relative Energy Deficiency in Sport (RED-S) and the Female Athlete Triad (Triad).

RED-S covers the broader consequences of chronic low energy availability. Included in that is the Female Athlete Triad, which comprises menstrual dysfunction, low energy availability (with or without an eating disorder), and osteoporosis (Nazem et al., 2012).

Together, RED-S and the Triad can influence metabolic function, bone health, immunity, muscle protein synthesis, and cardiovascular health. The results can lead to undereating (which is even more problematic for athletes), osteoporosis, amenohrea (which can result in different nutritional requirements due to the lack of cyclic hormone variation), and a general decline in athletic performance, endurance or otherwise, as in Figure 2a, showing the consequences of RED-S and the Triad, and Figure 2b indicating how those consequences can manifest.

Figure 2. Health consequences of relative energy deficiency in sport (RED-S); b. performance determinants of RED-S

References

Abdollahifard, S., Koshkaki, A. R., & Moazamiyanfar, R. (2014). The effects of vitamin B1 on ameliorating the premenstrual syndrome symptoms. Global journal of health science, 6(6), 144. 

Amzajerdi, A., Keshavarz, M., Ghorbali, E., Pezaro, S., & Sarvi, F. (2023). The effect of vitamin D on the severity of dysmenorrhea and menstrual blood loss: a randomized clinical trial. BMC women's health, 23(1), 1-7. 

Holtzman, B., & Ackerman, K. E. (2021). Recommendations and nutritional considerations for female athletes: Health and performance. Sports medicine, 51(Suppl 1), 43-57. 

Wohlgemuth, K. J., Arieta, L. R., Brewer, G. J., Hoselton, A. L., Gould, L. M., & Smith-Ryan, A. E. (2021). Sex differences and considerations for female specific nutritional strategies: a narrative review. Journal of the international society of sports nutrition, 18(1), 27.