What is the luteal phase and what does it mean for your fitness?

Unless you’re habitually using a period tracking app, your luteal phase might pass you by each month without you really noticing it.

During the latter half of your menstrual cycle, your body is in prep mode for its next period. Typically, there are two main phases going on: the early and the late luteal phase.²

This starts right after ovulation and lasts around three to five days, though the timing can vary from person to person.² “Oestrogen levels remain relatively high, but they gradually taper off as you approach your period,” says Dr Emma.

There are two potential benefits to training at the beginning of your luteal phase. You may find your muscles work longer without getting tired, and you might be able to burn fat more easily. This is because a rise in oestrogen and progesterone suppresses ‘gluconeogenesis’.⁴ This is the process by which your body makes a type of sugar called glucose. But research on this is still emerging.

“During the entire luteal phase, your body switches to burning fat rather than glucose as its main energy source,” explains Dr Emma. “Unlike glucose, which burns up quickly and can cause spikes and crashes, fat provides a slow and steady source of energy which is great for long-distance efforts.

To take advantage of the fat-burning efficiency, Dr Emma recommends opting for Low-Intensity Steady-State (LISS) exercises like cycling, long-distance running, swimming and hiking.

Lasting around three to seven days, the late luteal phase comes with a gradual decline of oestrogen and progesterone² – riding high during the earlier part – until their eventual drop-off during the premenstrual phase.

With lower levels of hormones, it’s common to feel big changes to your mood, energy and motivation.

All women are different, and some people might sail through this part of their cycle. But if you’re someone who struggles with sore boobs or heavy bloating, don’t beat yourself up for skipping those tougher fitness sessions.

Because progesterone naturally relaxes the gut and slows down digestion,⁸ you might feel constipated during the luteal phase. “It’s important to stay well-hydrated, eat small, frequent meals, and add in high-fibre foods to keep things moving along,” Dr Emma recommends.

To help keep your blood sugar stable, focus on meals with brown, starchy carbs like brown rice and wholemeal or seeded bread, lean proteins, and starchy vegetables like sweet potatoes and squashes, which will help keep you fuller for longer.

Take a look at how to exercise to make the most of your four-phase menstrual cycle to keep up with any exercise habits.