How to Train on Your Period — Your Menstrual Cycle Explained

Fitness creator Chrissy Chella breaks down the 28-day menstrual cycle into two clear phases and explains exactly how to adjust your training for each one.

Phase one is the follicular phase. Day one of your period is the reset button — energy levels are at their lowest, so gentle movement like walking or a light swim is ideal. By day three, estrogen enters the system and energy climbs steadily. This is the time to ramp up intensity: sprints, circuits, and HIIT workouts. Estrogen continues rising until roughly day 14, when testosterone and LH also peak for ovulation. Day 14 is when you'll feel your strongest, most confident, and most energized — the perfect window to chase personal bests and lift heavy.

Phase two is the luteal phase. Estrogen drops, progesterone rises, and the body shifts from burning glucose to burning fat. The same HIIT session that felt great in phase one will feel significantly harder. Training shouldn't stop, but expectations need adjusting — lower output is normal, not a sign of regression. As the phase progresses toward the next period, sleep quality declines, bloating increases, and energy bottoms out. Chrissy emphasizes reducing caffeine and screen time before bed during this window to support recovery.

The key message: understanding your cycle means you stop blaming yourself for fluctuating performance. External factors like stress, body fat percentage, and contraception also influence how each phase feels, so the 28-day framework is a guide, not a rigid rule.