Exercise and Your Menstrual Cycle
Periods are so taboo, right? I mean who wants to talk about the cramps, bloating, fatigue, cravings, and fluctuations in your workout performance during the month?
Well, I do.
The truth is your hormones have a huge impact on every system in your body and affect your fitness.
These natural fluctuations can explain why you struggle through a sprint session some weeks and feel like superwoman on others. But if you learn to work with, instead of against your physiology, you’ll rock your workouts all month long. Here are the ups and downs of a typical 28-day cycle and the best workouts to do during each part.
The graph above is based on a 28-day cycle, but cycle length can vary and be longer or shorter than this. I’m going to work across the graph from left to right explaining each phase and what’s happening.
Menstrual Phase (Day 1-7): this is the first day of your period and marks the start of a new menstrual cycle. Menstruation (or a period) is a shedding of the uterine lining and can last anywhere from 4-7 days. An average period sheds about 2 to 3 tablespoons (35 to 40 milliliters) of blood and tissue.
Your period also falls into the follicular phase of your cycle. This is where the levels of estrogen and progesterone are at their lowest so physiologically you are most “like a guy” here.
During this part of your cycle you have a higher pain tolerance, are more fatigue resistant, and you sweat more efficiently making it easier to go harder for longer. This is the optimal time physiologically to push those higher intensities at the gym because during the low hormone phase you are better able to tap into your glycolytic energy stores, providing your muscles with the energy they need for bursts of higher intensity work.
It should be noted both here and throughout everything I mention that although your physiology may be primed for pushing the intensity, listening to how YOUR body feels during each phase of your cycle is most important. For some women, their period means pain, discomfort, and fatigue, so pulling back here and focusing on form and how you feel may serve you best.
Follicular Phase (Day 7-14): your follicular phase continues here and the levels of follicle stimulating hormone (FSH) increase and signal to the ovaries to prepare an egg for ovulation. The dominant follicle produces estrogen as it grows. While this is happening, the uterus is responding to estrogen by building back up a thick uterine lining called the endometrium.
The increase in estrogen is also good for your gains in the gym as it is an anabolic hormone, meaning you are primed to build lean muscle and make strength gains. In fact, some research shows an increased response to resistance training in the first half of the menstrual cycle (menstrual + follicular) compared to the second (ovulation + luteal) so pick up the weights and focus on progressive overload here.
Ovulation (Day 14): When estrogen levels are high enough, they signal to the brain causing a dramatic increase in luteinizing hormone (LH), which leads to ovulation. This is where the egg is release into the Fallopian tube.
During this phase of your cycle your core body temperature rises about 0.5℃ higher and stays elevated for the remainder of your menstrual cycle. Your overall strength levels will peak here, but be sure to maintain good form as some studies also show an increased risk of ligament damage when estrogen levels are at their highest.
Luteal Phase (Day 15-28): this is the secretory phase of the menstrual cycle. Here there is a second surge of estrogen and progesterone. The hormonal changes of the luteal phase are associated with common premenstrual symptoms that many people experience, such as fatigue, mood changes, headaches, acne, bloating, and breast tenderness. During this phase, the endometrium prepares to either support a pregnancy or to break down for menstruation.
In terms of performance, you may feel more tired during this phase of your cycle and find higher intensity exercise more difficult as you cannot access the fast glycolytic energy stores as easily. Your core body temperature is also higher meaning you may feel hotter, sweat more, and have a faster time to fatigue when doing cardiovascular exercise.
On the plus side, you’ll burn more calories overall as the increased core body temperature also means an increased metabolic rate of about 5 – 10%.
The natural fluctuations in your menstrual cycle and the associated changes in performance should always be viewed through a lens of personal experience. By that I mean, you know your body best! If you truly want to harness the power of your hormones, the most helpful thing to do is track your cycle and variables of performance in the gym to figure out when YOUR personal peak is each month and when you need to pull things back. The key is to work with your physiology and not against it to train smarter, not harder.