The Menstrual Cycle: What’s normal and what’s not
Module aims
- Provide an outline of the menstrual cycle and the hormones involved, including what you can expect during the primary three phases (follicular phase, ovulation, luteal phase)
- Deliver insight on how the menstrual cycle may influence training and performance according to the latest research
- Describe the signs and symptoms of menstrual irregularities and highlight when to seek further help from a medical practitioner
What are the important hormones involved in a menstrual cycle?
Estrogen and progesterone are two of the most important hormones in the female body, both playing critical roles in the normal reproductive development and function of your body. Your ovaries produce most of your estrogen and progesterone during your reproductive years. Your adrenal glands also release small amounts of estrogen and progesterone and, should you become pregnant, your placenta will too.
Note, while they are often thought of as ‘female hormones’, they are also found in men.
The primary roles of the hormones
| Estrogen | Progesterone |
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How can the menstrual cycle influence swimming performance
Your body’s levels of estrogen and progesterone naturally change throughout the menstrual cycle, after childbirth and throughout menopause. This can affect an athlete’s performance with research linking the hormonal fluctuations with changes in heart and breathing rate, metabolism and body temperature.
| Estrogen | Progesterone |
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What is a menstrual cycle?
The menstrual cycle is more than just a period. It’s a series of changes in the ovaries and uterus that prepares your body for a possible pregnancy. This is controlled by a complex interaction of hormones including luteinising hormone (LH), follicle-stimulating hormone (FSH), estrogen and progesterone throughout your menstrual cycle.
The follicular phase
The follicular phase typically occurs between day one and day 12 of the average 28-day cycle. If your cycle isn’t exactly 28 days, don’t worry! You can figure out when your follicular phase starts by working out when your luteal phase ends and working backwards.
Whole cycle length – Luteal phase length =Follicular phase length
During your follicular phase, your body is preparing to release an egg. This involves the growth and maturation of follicles in your ovaries. During the first few days of the cycle, several follicles are stimulated due to a rise in follicle-stimulating hormone (FSH).
| What to expect
Low estrogen, low progesterone
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Ovulation
Ovulation typically occurs between day 12 and 15 of a 28 day cycle, when a mature egg is released from the follicle. This can happen on different days for different women, depending on their cycle length. Ovulation occurs when a surge of the hormone , Luteinising hormone (LH), is released after estrogen levels rise from the growing follicle.
If sperm is present in the fallopian tube at the time of ovulation, the egg can be fertilised leading to pregnancy if the developing embryo reaches the uterus and implants. If not, the egg will dissolve in the fallopian tube after about 12 to 24 hours.
If you are interested in learning more about ovulation for fertility reasons, we recommend speaking with an Ignite Athlete specialised women’s health GP.
| What to expect
High estrogen, low progesterone
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The luteal phase
The luteal phase usually starts after ovulation around day 15 in a 28 day cycle. If you do not have a typical 28-day cycle, your luteal phase can be determined by counting back 14 days from your first day of bleeding.
During this phase, the follicle that released the egg becomes the corpus luteum and produces the hormones progesterone and estrogen to provide nutrition to the lining of the uterus (the endometrium). This keeps the uterus prepared for pregnancy.
If a developing embryo does implant into the uterine wall and pregnancy does occurs, a hormone called human chorionic gonadotropin (hCG) is produced. The production of hCG causes the ovary to continue producing progesterone which is necessary to support the pregnancy.
Alternatively, if there is no fertilisation or implantation, the ovary stops producing progesterone and your period starts as the uterus sheds its lining.
| What to expect
High estrogen, high progesterone Most people also experience symptoms in the days leading to their menstrual period which are referred to as premenstrual syndrome (PMS) symptoms. This can vary between people and each menstrual cycle with common symptoms experienced include, but are not limited to:
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What’s normal for a menstrual cycle?
- Cycle length: 21-35 days that occurs on a regular schedule (no more than +/- 3 days)
- Menstrual bleeding length: 3-7 days with no large clots (i.e., no clots larger than a 10-cent piece)
- Menstrual bleeding amount: approximately 50 mL (2-3 tablespoons) total – no flooding of pads or changing tampons every hour
How to track your menstrual cycle
Tracking your menstrual cycle each month can give you a better idea what’s going on in your body and help you better understand your overall health.
Menstrual cycle tracking has many benefits as it allows you to:
Identify any menstrual abnormalities
Keeping track of your period can help you figure out what’s normal for you, and help you spot any changes or irregularities in your cycle that may need a doctors attention.
Your tracking log will also help your doctor in getting a more comprehensive idea of your menstrual cycle, helping them to better understand your individual circumstances.
Ensure your training is working with your cycle
By keeping track of your period, you can figure out how your workout routine and other activities are affected by your cycle. This information can be particularly helpful in assisting you to see patterns in your performance, recovery, and susceptibility to injury at different times of your cycle.
While the research in this area is still developing, your experience of how your menstrual cycle interacts with your athletic performance may vary from research based on your age, sport, and stage in your career. This is why keeping track of your own individual cycle can help you make adjustments to optimise your performance and preparation that work for you.
So how can I track my period
Keeping track of when your period starts each month is a great way to start tracking your cycle. The first day of your period is the first day of your menstrual bleeding.
For a more comprehensive picture of your menstrual cycle, we also recommend you consider the following questions when logging your menstrual cycle:
- Have you experienced any premenstrual syndrome (PMS) symptoms?
- When did menstrual bleeding begin?
- How many days did your period last?
- Have you experienced any bleeding between periods?
- What symptoms did you experience during your period?
There are also a variety of period tracking apps available that can help you track everything from your period length to the PMS symptoms you may be experiencing. Period tracking apps we recommend include:
- Garmin Connect – Menstrual cycle tracking
- Apple Cycle Tracking app
- FitR woman
- Flo
Keep in mind, some period tracking apps may not be totally accurate or cater to athlete needs’ with their suggestions. These apps are best used for tracking the pattern of your period, providing a convenient way to track and record your symptoms at various times.
How does it influence athletic performance?
The effect of the menstrual cycle on athletic performance is being increasingly recognised as a key consideration for women’s sport. This is important as menstrual-related symptoms are very common with symptoms often affecting athlete’s daily life, as well way they train and compete.
There are many different factors that can affect performance during a menstrual cycle, including changes in body temperature, metabolism, muscle strength and body composition.
However due to limitation in research, the current research is variable and individualised to the different types of athletic groups (i.e., amateur vs elite), age groups and within sports. While research is growing, it is important to know some athletes may feel a big difference in performance during different stages of their cycle, and some may not. This is why tracking your menstrual cycle and documenting how you think, feel, train, and perform at different stages is so important to see how your body responds.
Nevertheless, current research suggests some athletes may experience the following effects:
| Follicular phase | Ovulation | Luteal phase |
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When to see a doctor?
We recommend you seek the advice of a specialised women’s health General Practitioner (GP) if you experience any of the following:
- Significant changes in the pattern of your period
- The absence of a period
- Heavy bleeding (e.g., flooding of pads, changing pad/tampon every hour etc.)
- Large clots present during your period
- Severe pain that impacts on your daily activities
- Vomiting or nausea
- Blood in urine or bowel motion
- Urinary incontinence
They will assess your symptoms, and where relevant, refer you onto a gynaecologist for further investigation.
If you have concerns about your menstrual cycle, we encourage you to get in touch with us. We have a network of specialised General Practitioners, gynaecologists and fertility specialists across Australia who will be more than happy to speak with you and discuss your individual circumstances.
With over 50 dedicated specialists across 70 consulting locations throughout the country, our friendly staff can help you choose the right medical professional to guide you and help you achieve your sporting goals. Contact us now.
Summary
- The menstrual cycle is more than just a period, it’s a complex interaction of hormones with three primary phases (the follicular, ovulation and luteal phase).
- A normal menstrual cycle is between 21-35 days in length, occurs regularly (no more than +/- 3 days), and involves 3 to 7 days of menstrual bleeding around ~50mL in volume (no blood clots, or changing of pads/tampons every hour).
- The menstrual cycle can influence athletic performance, although its effect can be different between athletes highlighting the importance of tracking your period.
- As an athlete, tracking your period is important and can be managed in many ways including on paper, or via one of our recommended period apps.
- If you experience any symptoms that concern you, please seek the advice of a specialised women’s health GP.
