Understanding the Menstrual Cycle: Hormones, Symptoms, Nutrition and Exercise for Each Phase

Author: Olivia Macor, BASc (Candidate)

Reviewed by: Dahlia Abou El Hassan, MScFN, RD

The menstrual cycle is a complex process regulated by hormones that influence a woman’s reproductive health, energy levels, and overall well-being. A typical cycle lasts around 28 days, though a healthy range can be anywhere from 21 to 35 days. Cycles shorter or longer than this, as well as irregular periods or amenorrhea (the absence of menstruation), may indicate underlying health concerns that require further investigation. Understanding these hormonal shifts can help optimize nutrition, exercise, and lifestyle choices for better health and fertility. Here’s a breakdown of each phase, the hormones involved, common symptoms, and recommended nutrition and exercise strategies.

1. Menstrual Phase 

The menstrual phase begins when the uterine lining sheds, leading to menstruation. This occurs due to a drop in estrogen and progesterone levels, signaling the body that pregnancy has not occurred. Common symptoms include cramps, fatigue, headaches, and low energy.

During this time, the body is losing iron through menstrual blood, making it important to consume iron-rich foods such as spinach, lentils and red meat. Pairing these with Vitamin C-rich foods like citrus fruits, bell peppers, and strawberries can enhance iron absorption. Gentle exercise like stretching, yoga, or walking can help alleviate cramps and improve circulation without overexertion.

2. Follicular Phase 

As menstruation ends, the body enters the follicular phase, during which the pituitary gland releases follicle-stimulating hormone (FSH). FSH stimulates the growth of follicles in the ovaries, one of which will mature into an egg. Estrogen, mainly produced by the developing follicles, begins to rise, thickening the uterine lining to prepare for a possible pregnancy. Estrogen also boosts energy, mental clarity, and mood. 

This is a great time to focus on nutrient-dense foods like lean proteins, healthy fats, and fibre-rich carbohydrates to support your body such as oats, quinoa, beans, and berries. Higher energy levels during this phase make it ideal for strength training and more intense workouts.

3. Ovulation Phase 

Ovulation occurs when a surge in luteinizing hormone (LH) triggers the release of a mature egg from the ovary. Estrogen is at its peak, and testosterone levels also rise slightly, increasing libido and confidence. 

Since this is the most fertile window, nutrition should support egg quality and reproductive health. Antioxidant-rich foods like berries, dark leafy greens, and nuts help protect the egg from oxidative stress. Zinc, found in pumpkin seeds and chickpeas, is crucial for ovulation. Hydration is also key during this phase! Moderate-intensity exercise like cycling, dancing, or resistance training is beneficial, but avoiding excessive stress on the body is key.

4. Luteal Phase 

After ovulation, the body enters the luteal phase, where progesterone levels rise to prepare the uterus for a possible pregnancy. Progesterone, produced by the corpus luteum (the structure that forms from the follicle after ovulation), helps maintain the uterine lining and supports early pregnancy. If no fertilization occurs, hormone levels gradually decline, leading to PMS symptoms such as bloating, irritability, cravings, and fatigue. Progesterone can also slow digestion, which may contribute to constipation and further bloating during this phase.

During this phase, blood sugar fluctuations may increase cravings for sweets and processed foods, making it important to focus on balanced meals with protein, healthy fats, and fibre to maintain stable energy levels. Magnesium-rich foods like dark chocolate, almonds, and bananas can help with mood regulation and cramp relief. Gentle movement like walking, pilates, or restorative yoga can reduce bloating and stress.

Why This Matters for Fertility and Overall Health

Understanding the menstrual cycle helps women support their hormonal health, manage symptoms, and track fertility. Estrogen plays a key role in preparing the body for ovulation, while progesterone ensures the uterine lining is ready for implantation. FSH and LH work together to regulate ovulation and follicle development. Tailoring nutrition and exercise to each phase can improve energy levels, support hormones, and reduce discomfort. For those trying to conceive, optimizing diet and lifestyle during each phase can improve reproductive outcomes. Even for those not planning pregnancy, cycle awareness is a valuable tool for overall well-being, helping women feel more in tune with their bodies and make informed health choices.