• Alice Clarke

Effects of the Menstrual Cycle on Performance

The topic of whether the unique female physiology requires a tailored training approach has historically been ignored and even considered taboo by some. However, the impacts of female physiology on training and performance has long been a subject of discussion for female athletes and coaches and is now beginning to filter into the wider athletic population.


One of the key physiological characteristics that differentiates males and females is hormones; predominantly the prevalence of oestrogen and progesterone in females and testosterone in males. A key role of these hormones in females is to maintain a healthy, functional menstrual cycle. Research has indicated that more than half of female athletes have noticed a negative impact on their training and performance due to the hormone fluctuations that occur during the menstrual cycle.

Before we get into the science and research, let us have a quick re-cap on the menstrual cycle. There are 4 key hormones involved in the various stages of the cycle: Oestrogen, luteinising hormone (LH), progesterone and follicle stimulating hormone (FSH). Each cycle is 28 days long and around the middle of the cycle is when there is a peak in oestrogen, LH and FSH. This spike coincides with the release of an egg and is when the female can become pregnant. Following this is the luteal phase; the high hormone phase where both oestrogen and progesterone levels peak.

A recent study indicated that up to two-thirds of female athletes experienced menstrual cycle-related problems that negatively impaired their performance. The impacts noted extended further than physiological symptoms, such as back pain, and included issues such as the perceived impact of menstruation on aspects of daily life and performance and the methods involved in dealing and adaption to menstruation impacts. Other studies commonly showed fluctuations in strength, metabolism, inflammation and injury risk associated with hormonal fluctuations throughout the cycle. Further research means that it has been possible to associate various performance impacts with the various different phases of the menstrual cycle.


Follicular phase:

- Due to a higher pain tolerance and energy levels, this is the best time for female athletes to undertake high-intensity workouts.

- The rise in oestrogen during the late follicular phase is related to negative impacts on pre-exercise carbohydrate storage. Carbohydrate loading the day before and during exercise might be important for female endurance athletes to be able to exercise at high intensities.

- Strength training may be more effective due to the higher oestrogen levels during the late follicular phase.


Ovulation phase:

- A significant increase in muscle strength during ovulation compared with the follicular and luteal phases has been shown, meaning this could be the time to achieve a personal best.

- Some research suggests athletes are at a higher risk of injury during this phase.


Luteal phase:

- Hormonal fluctuations mean that the body is not as effective during high-intensity training.

- Effects of pre-menstrual syndrome (PMS) might interfere with training and performance around 7–10 days before menses begins.

- Body mass may increase due to fluid retention.


It is important to remember that the menstrual cycle is part of a bigger health concept in female athletes. Low energy availability – the concept when energy intake and expenditure are not in balance, can lead to irregular periods or loss of menses entirely, as well as problems with bone health; a condition termed the Female Athlete Triad. Other disturbances to normal physiological function may also be observed such as reductions in metabolic rate, immunity, protein synthesis, and cardiovascular health. Another concept, known as ‘relative energy deficiency in sports’ (which can also be observed in male athletes), builds on the concept of the Female Athlete Triad by taking into account other aspects of health and performance, such as injury risk and concentration.


Many female athletes will use some form of hormonal contraceptive that affects their menstrual cycle. However, the research into the impact of these hormonal contraceptives on performance is sparse and unconclusive and more trials are needed to conclusively determine their bearing on performance in female athletes.


The take home message from this is that the low-hormone follicular phase is suggested to be the optimal time for performance. However, because of the high individual variability reported in performance and side effects experienced during the menstrual cycle, athletes and practitioners should maintain an open dialogue to pursue the best interests of the athlete.



References:

Findlay, R., Macrae, E., Whyte, I., Easton, C. and Forrest (née Whyte), L., 2020. How the menstrual cycle and menstruation affect sporting performance: experiences and perceptions of elite female rugby players. British Journal of Sports Medicine, 54(18), pp.1108-1113.


Burrows, M. and Peters, C., 2007. The Influence of Oral Contraceptives on Athletic Performance in Female Athletes. Sports Medicine, 37(7), pp.557-574.