Understanding The Menstrual Cycle's Effect on Athletic Performance.

The evidence to show that menstrual cycle affects female athletes training, performance, and recovery.

Written by Dr. Anthea Clarke, Senior Lecturer Sport and Exercise Science, LaTrobe University

We measure how far and fast athletes move when training, we track HR and power output, cadence and stride frequency, and we check in to know how hard a session felt and whether athletes were sore or fatigued.

For female athletes, there is enough evidence now to show that a substantial portion feel that their menstrual cycle affects their training, performance, and recovery.

Up to 70% of surveyed female athletes perceive their performance to be negatively affected at certain phases of their menstrual cycle, with the majority reporting multiple menstrual related symptoms (such as pain, bloating, and low energy), particularly in the lead up to and during menstruation. So why would we not want to capture this information in our athletes? Menstrual cycle tracking can provide context to individuals’ health, training responses, and improves the autonomy of female athletes to better understand their own body and how their menstrual cycle interacts with their training.

There are four phases in a normal menstrual cycle: menstruation, the follicular phase, ovulation, and the luteal phase. The first day of an individual's’ period (menstruation) is the start of the menstrual cycle. This is characterised by low levels of the two main female sex hormones, estrogen and progesterone. A typical length for a period is between 2-7 days. This phase is also incorporated into the follicular phase, where estrogen levels start to increase while progesterone levels stay low. This phase typically lasts around 2 weeks. Towards the end of the follicular phase the body starts to produce follicle stimulating hormone (FSH) and luteinizing hormone (LH) to prepare for ovulation (release of an egg from the ovaries). Ovulation typically occurs about two weeks prior to the next period. Following ovulation, both estrogen and progesterone levels are high, before dropping to initiate the next menstrual bleed if pregnancy has not occurred. It is thought that this drop in hormone levels leading into menstruation is what contributes to the presence of common menstrual-related symptoms. As the hormone levels within each cycle can change, and is different for everyone, the symptoms and severity can vary greatly both within and between individuals each month.

The most common symptoms that are reported, mainly in the days leading into their period or during the first couple of days of having their period, include fatigue, irritability and mood disturbances, cramps, and bloating. However, these symptoms can occur throughout the menstrual cycle and it is worth identifying what is typical for each individual. We also typically think of menstrual related symptoms as always being negative. But some symptoms can be very positive experiences and are worth acknowledging when an athlete feels good across their menstrual cycle. Menstrual-related symptoms are not exclusive to those with a natural cycle either; hormonal contraceptive users often report experiencing menstrual-related symptoms. 

To date, research is not supportive of the need to structure training or nutritional intake to the phases of the menstrual cycle. This is due to the limited amount and quality of research in the area. However, the considerable variation in women’s experiences of the menstrual cycle may also contribute to any possible findings being washed out within the average. This is why the current recommendation is to take an individualised approach to training across the menstrual cycle with athletes. While reasonably feasible to achieve in individual sports, this gets more difficult when working with multiple athletes and in team-sport environments. That’s where educating players to be more autonomous comes in - allowing individuals to understand how their body responds across the cycle and learning to recognise what their body needs (more/less training, more carbohydrates, or rest, for example).

One particularly useful outcome of tracking the menstrual cycle is the ability to identify what is normal for each individual, as well as when something starts to change. Changing cycle length, period characteristics, and pain can signify that something may not be right and is worth getting checked out. A common cause for concern around the menstrual cycle in athletes is a missed period (in the absence of pregnancy). Not having a period for 3 months or greater is termed secondary amenorrhea (primary amenorrhea is not having a period by the age of 15). The menstrual cycle can act like a canary in the coalmine, where the absence of a period is a signal that the body is not coping and is starting to shut down non-essential functions (e.g. the ability to reproduce). In athletes, secondary amenorrhea is a common sign of relative energy deficiency in sport (RED-S).

RED-S occurs when there is insufficient energy consumed for the amount of activities being undertaken, e.g. with training. Previously termed the Female Athlete Triad, that connects low energy availability, menstrual disturbance, and low bone mineral density, RED-S acknowledges the far-reaching impact that low energy availability may have on individuals (both females and males). In addition to impaired bone health, the presence of RED-S influences the ability to perform and recover from exercise (decreasing muscular strength, endurance, and glycogen stores), impairs mood and cognitive function (including coordination, concentration, and judgement), and increases an individuals’ injury risk.

Given these potential impacts of RED-S on training and performance, early identification and management becomes key. This is where menstrual cycle tracking comes in. Having athletes regularly report the presence of menstrual bleeding and symptoms experienced across a cycle helps to identify what is normal for that individual and can flag when things may start to change. There are numerous ways to track the menstrual cycle, with many health and fitness products now offering these services, from watches to phone apps, to a simple paper diary or calendar. If using a digital platform to record this information, it is important you know your rights when it comes to ownership and access to your data.

For a coach interested in integrating menstrual cycle tracking into an athlete management system, it is essential you undertake the following things; 1) clearly articulate with your athletes the reasons for data collection and who will have access (including education where needed), 2) understand how you intend to use the data collected (primarily for health reasons, and/or in an individualised manner with athletes based on positive/negative symptomatology), and 3) have clear referral systems in place should an athlete flag any concerns, involving a sports doctor and dietitian.

What’s most important is that coaches and practitioners are creating an environment where athletes feel comfortable to discuss their menstrual cycle or any other health or performance-related aspect of their lives with you. Empowering athletes and their coaching team to work with the menstrual cycle rather than trying to pretend it doesn’t exist is going to be far more effective at building a lifelong love for their sport and stronger coach-athlete relationships, with improved performance an added bonus. 

Thanks again to Dr. Anthea Clarke for her insight and expertise from this content.

The team and Lumin Sports are really excited to announce that Arc now gives athletes the option to report on their menstrual cycles and describe symptoms, during the daily check-in process.

Tracking and recording menstrual cycle data allows coaches to plan, prepare and train female athletes appropriately during the phases of the menstrual cycle.

The feature was developed in conjunction with female performance experts to deliver appropriate and valuable insights to improve and consider the health, safety and performance outcomes of female athletes.

Learn more and download a demo via: luminsports.com/request-demo