The various phases of the menstrual cycle and accompanying hormones affect how you feel and athletic performance. Learn how to make your hormones work for you!
Written by Lydia Carron (Medically Reviewed by Natalie Rizzo, MS, RD)
Hormones are one of those subjects that seem vague and complicated. You know you have them and that they impact your mood, hunger, fertility, etc., but how and why?
Hormones can have nasty side effects, like cramps, mood swings or fatigue. And those side effects can interfere with everyday life and athletic performance. But what if you could exercise, eat, and sleep in a way that worked with your hormones?
By understanding your hormones and how they fluctuate throughout the month, you’ll have a better grasp on how to manage them and feel your best.
What are hormones anyways?
Simply put, hormones are chemical messengers in the body that help maintain functions like growth, development, cognition, and emotions. Many hormones are named after the gland or organ that secrete them, such as thyroid hormones (from the thyroid gland).
Hormones are affected by a variety of internal and external cues. For example, getting insufficient or poor-quality sleep can impact hunger hormones, which regulate appetite.
For women, hormonal changes occur in conjunction with your menstrual cycle. Certain hormones, like estrogen, progesterone, luteinizing hormone, and follicle-stimulating, help the female body prepare for a potential pregnancy.
These hormones coincide with physical symptoms that we’re all too familiar with, such as headaches, cramping, bloating, and fatigue. By understanding when and how these hormones act on the body, you can begin to make lifestyle changes that support hormonal fluctuations and decrease unwanted side-effects.
The different phases of the menstrual cycle
Most women think of their period as the 5-8 days each month when they experience bleeding, cramps, bloating, fatigue, and mood shifts. As a matter of fact, an estimated 80- 90% of all women experience one or more of these symptoms. However, the menstrual cycle encapsulates hormonal changes occurring over 24-38 days (with an average of 28 days). This recurring cycle prepares the uterus for a (potential) pregnancy.
The menstrual cycle is split up into two phases: the follicular phase and the luteal phase. The follicular phase length varies more than the luteal phase, which is consistently around 12-14 days. In between these two phases, ovulation occurs. Let’s take a look at the timeline of the average menstrual cycle.
Follicular Phase (Hormones: Estrogen & FSH)
Day 1 of your cycle begins with menstruation or the shedding of the lining of the uterus. This is the time most often referred to as a “period.”
The beginning of menstruation is also the start of the follicular phase. This phase varies in length, and it’s marked by an increase in estrogen levels. During the follicular phase, the brain uses a hormone called follicle-stimulating hormone (FSH) to send a message to the ovaries to release an egg for ovulation.
Let’s look more closely at estrogen and FSH…
There are three naturally occurring forms of this hormone: estrone, estradiol, and estriol. Of these, estradiol is the one that we are most concerned with and has the greatest impact on physical and mental changes throughout the menstrual cycle.
Estrogens are responsible for growth, development and maintenance of sex characteristics (ie higher vocal cords, female body shape, breast growth), the growth of the uterus, the release of luteinizing hormone (more on this later), the thickening of the vaginal wall, and the development of milk ducts in the breast during pregnancy.
The primary action of estrogen, in terms of menstruation, is the thickening of the uterine lining, also known as the endometrium. This thickening creates a hospitable environment for the potential fertilized egg to grow.
Follicle-Stimulating Hormone (FSH)
This hormone is created by the pituitary gland, which is located at the base of the brain. It’s responsible for estrogen production inside the follicle–a little fluid-filled sac within a woman’s ovaries that contains an egg.
Each follicle releases one egg for fertilization; for this reason, “follicle” is often used interchangeably with “egg.” Although there are many follicles in each ovary, there is only one principal follicle that is released at ovulation. This main follicle produces estrogen as it grows within the ovary.
Ovulation (Hormone: Luteinizing Hormone)
Around day 14, ovulation occurs and marks the time between the follicular and luteal phases. The time of ovulation can vary based on the length of your normal cycle. It usually occurs around Day 14 for a 28 day cycle, but it may be later for a longer cycle.
Before ovulation, the matured egg or follicle produces estrogen, which signals the brain to increase luteinizing hormone.
Luteinizing Hormone (LH)
Like follicle stimulating hormone, luteinizing hormone is also made by the pituitary gland. It plays an important role in sexual development and function. Right before ovulation, LH rises rapidly, which triggers the release of the egg from an ovary.
The egg breaks through the wall of the ovary, starting ovulation. The released egg travels along the fallopian tube into the uterus. Although the egg only survives in the uterus for about 24 hours, sperm can survive in the female body for up to five days.
The period when the egg can be fertilized by the sperm is called the “fertile window”. A non-fertilized egg will disintegrate and leave the body at the beginning of a new menstrual cycle (about 12-16 days after ovulation).
Luteal Phase (Hormones: Progesterone & Prostaglandins)
The luteal phase occurs around days 15-28. It begins after ovulation and lasts until the start of a new menstrual cycle, i.e. the first day of bleeding. The follicle that contains the egg in the ovary turns into a corpus luteum and produces progesterone and estrogen.
The corpus luteum secretes progesterone, a hormone that thickens the uterine lining in preparation for a fertilized egg. If fertilization does not occur, the corpus luteum breaks down 9-11 days post-ovulation and is shed from the body.
This results in a drop in estrogen and progesterone levels. If an egg is fertilized during ovulation, progesterone continues to rise.
The luteal phase is associated with “premenstrual” (PMS) symptoms, such as headaches, acne, bloating, tender breasts, mood changes, nausea and/or vomiting. In fact, there are over 150 different symptoms associated with PMS!
Why do women get cramps during the luteal phase?
During the luteal phase, the increase in progesterone levels cause the lining of the uterus (endometrium) to stop thickening in order to receive and attach a fertilized egg. This period is also called the “secretory phase” because the endometrium produces chemical messengers (hormones), such as prostaglandins.
Prostaglandins widen blood vessels, increase blood flow and help the uterus contract and relax, allowing the thickened endometrium to detach from your uterus and flow out of your body during your period.
You experience cramping when an excess of prostaglandins causes the uterus to contract so strongly that it reduces blood flow to the uterus. Don’t be alarmed! This process is normal and necessary.
However, if you experience debilitating or unbearable pain, talk to your healthcare provider about possible medications or other solutions. NSAIDS (non-steroidal anti-inflammatory drugs), such as aspirin and ibuprofen, block the actions of prostaglandins, therefore lessening pain from cramps.
How does the menstrual cycle affect athletic performance (and what can you do about it?)
As you can see, there are a LOT of hormonal changes happening throughout a woman’s body during the menstrual cycle. The good news is that exercise has been shown to reduce period pain!
Remember those pesky prostaglandins from the luteal phase? Exercise counteracts the effects of prostaglandins, increasing blood flow to the abdomen and uterus, which results in fewer and less intense cramps!
Generally speaking, during the first half of your cycle (follicular phase), right after the first day or two of bleeding, you may have more energy and experience a more stable mood due to the increasing hormones. The week before ovulation is the perfect time to do higher intensity or longer workouts, such as HIIT, long runs, boxing, rowing or swimming.
The second half of the cycle (luteal phase) is when you’re more likely to feel lethargic. During these two weeks, hormone levels are dropping but prostaglandins are increasing, so you may experience gastrointestinal issues, migraines, and a drop in serotonin.
Pay attention to your energy levels and how you feel. Lower intensity exercises, such as yoga, pilates, and walks, will get your blood flowing without exacerbating your symptoms. It’s a good idea to get adequate sleep during the luteal phase, which will ensure you’re not completely foggy and zapped of energy during the day.
Lydia Carron is a dietetic intern with an MS in Nutrition Education from Teacher’s College, Columbia University. Originally from New York City, she modeled professionally for 5 years, which precipitated her interest in women’s hormonal health and nutrition. Her favorite physical activities are boxing, running, yoga, and hiking. See more of Lydia’s tips and advice on her Instagram, @LydiaTreatNutrition.