The four phases of the menstrual cycle, explained plainly

A menstrual cycle is counted from the first day of bleeding to the day before the next bleed begins. Across that span, the hormones estrogen and progesterone rise and fall in a fairly predictable pattern, and that pattern is what the four-phase model describes.

The phases are a shorthand for the hormonal backdrop, not a description of how any one person feels. Two people in the same phase can have very different days, and the same person can feel different in the same phase from one month to the next.

The cycle starts with menstruation, when the uterine lining sheds. Estrogen and progesterone are both at their lowest points. Bleeding commonly lasts several days, though what is typical varies a lot between people.

Some people feel tired, crampy, or low in this phase. Others feel light and energetic once the first day or two has passed. Both are ordinary.

Overlapping with the bleed and continuing after it, the follicular phase is when the ovary prepares an egg and estrogen climbs steadily. Many people report feeling more energetic and more able to push harder training in this stretch, but this is a tendency in reports, not a guarantee.

Around the middle of a typical cycle, a surge in luteinizing hormone triggers ovulation, the release of an egg. Estrogen peaks just beforehand. The window is short, often a day or two of notable change, and its timing shifts from cycle to cycle, especially if your cycles are irregular.

Some people notice a change in cervical mucus, mild one-sided discomfort, or a lift in energy. Others notice nothing at all.

After ovulation, progesterone rises and body temperature runs slightly higher. If pregnancy does not occur, both hormones fall and the next bleed begins. The luteal phase is where many people notice premenstrual symptoms such as bloating, breast tenderness, sleep disruption, mood changes, or cravings.

The luteal phase is not always a low-energy phase. It is simply the phase where a subset of people notice more symptoms, and where paying attention to sleep and recovery tends to matter more.

Cycle length differs between people and even between cycles for the same person. Many adults fall somewhere in the range of roughly three to five weeks, and a difference of a few days from month to month is common. In the first years after periods begin, and again in the years approaching menopause, cycles tend to be less predictable.

What tends to matter more than hitting a specific number is your own baseline. A pattern that is steady for you is usually reassuring; a sudden, lasting change from your usual pattern is worth noting in your log and, if it persists, raising with a clinician.

Estrogen is associated with building up the uterine lining and, in many people, with feeling more energetic and resilient. Progesterone is associated with stabilizing that lining and tends to raise body temperature slightly and make some people feel sleepier or more sensitive.

These are broad tendencies. Hormone levels are influenced by sleep, stress, nutrition, illness, medication, and training load, and the way your body and brain respond to the same hormone level is individual. That is one reason two people on the same day of the cycle can feel completely different.

Cycle length, ovulation timing, and symptoms all vary. Hormonal birth control, perimenopause, postpartum changes, conditions such as PCOS, stress, illness, and under-eating can all change or blur the pattern.

That is why Foviq treats the phase as a small prior and lets your reported symptoms carry most of the weight. A useful rule of thumb: let the phase suggest what to watch for, and let today's sleep, soreness, energy, and mood decide what to do.

• Your own logged history is the best predictor of your own cycle.
• If your cycles are very irregular, phase labels are least reliable and symptoms matter most.
• On hormonal contraception there is no natural ovulatory peak, so a phase chart may not describe you.