Exercise and your Menstrual Cycle
Have you noticed that throughout each month there are days where you feel stronger than others? Or perhaps, you feel low on energy and prefer to do light exercises. Your hormones could have a lot to do with this. Understanding your menstrual cycle can provide you with the information you need to take control of your exercise routines and get the best out of each workout. Unfortunately, the science is not yet clear on how your hormones impact your exercise and we know that it can differ for each person. What we can provide you, is a snapshot of what many people experience throughout their menstrual cycle.
But first, let’s learn the two main hormones involved in menstruation:
Progesterone: A hormone released by the corpus luteum in the ovary after ovulation designed to prepare the uterus for pregnancy. If pregnancy occurs, progesterone plays an important role in early pregnancy to increase blood flow to the uterus. If pregnancy doesn’t occur, a sudden drop in progesterone triggers menstruation.
Oestrogen: A hormone released by the ovaries and are an important part of puberty, menstruation, pregnancy, bone strength and maintenance of cholesterol. Oestrogen levels are at their highest at the middle of your cycle, around ovulation day. Oestrogen levels will drop just prior to menstruation. Oestrogen will also drop during menopause.
Follicular phase – Days 1 – 14
The follicular phase starts on day 1 of your period and goes until ovulation day (usually around day 14). Your ovaries are stimulated to produce 5-20 follicles, each usually housing 1 immature egg. Generally, only 1 follicle will mature into an egg.
Days 1 -7 (week 1 of cycle) – The thickened lining of the uterus is eliminated causing a period that lasts for 3-7 days. Your oestrogen and progesterone are low and typically you will have a higher carbohydrate utilisation in your energy systems. This means the first week is the perfect time for interval training or high-intensity interval training (HIIT).
Days 8-14 (week 2 of cycle) - Oestrogen begins to increase whilst progesterone continues to decrease. There is also an increase in natural growth hormone during this week making this the perfect time for strength training. Use this week to increase weights, sets or reps for maximal growth and strength.
Ovulation day – approx. day 14
The follicle bursts and the egg is released from the ovary into the fallopian tubes. The empty follicle remains on the ovary surface and transforms into the corpus luteum.
Luteal Phase – Days 15 – 28
The corpus luteum stimulates a hormone to thicken the lining of the uterus ready for implantation of a fertilised egg. At this stage progesterone is increasing and will continue to increase until 2-3 days before menstruation. If there is no fertilised egg, the corpus luteum dies causing this drop in progesterone. Oestrogen will also drop 2-3 days before menstruation.
Days 15 – 21 (Week 3 of cycle) - Typically have a higher fat utilisation for energy. This means cardiovascular / endurance training is optimal during this week. Lengthen your run, cycle a little faster or add some skipping to your workout for best results.
Days 22-28 (week 4 of cycle) – Progesterone is at its highest followed by a sudden drop for the last 2-3 days in preparation for menstruation. Fat utilisation remains higher here, but you may start to experience PMS (pre-menstrual syndrome) symptoms and low energy levels. Try gentler exercise during this week like yoga, Pilates, swimming or focus on your skill refinement.
Everyone’s menstrual cycle is different. They can vary in length from 21-40 days. This will affect when each of these phases occur but if you can tune into your body, you will start to feel what your body needs and be able to optimise your performance.
There is still a lot of research that needs to be done in this area, but more researching is happening, and we are learning more and more about how amazing our bodies are.