Updated: May 10
Have you noticed that sometimes you feel on fire to work out, and other times it's the last thing on earth you want to do? Since I learned about Menstrual Timing of Training (MTT) back in 2017, I have completely started scheduling my workouts around my cycle and it has been a game-changer!
I've been charting my cycles with Fertility Awareness since 2011, so I can always pinpoint when I ovulate and when certain hormones are at their peak. I've noticed time after time that towards the end of my cycle, when progesterone is about to drop, and during my period, when all hormones are very low, I feel fatigued and totally uninspired to work out. I just want to eat, sleep, and rest. On the other hand, when my estrogen is rising and I enter my fertile window, my body really craves exercise, and I have a much higher tolerance for heavy workouts.
In the past, I had always believed I should just push through the fatigue, since consistency with exercise is what's important, right?
Then I came across this fantastic article by Stijn van Willigen about Menstrual Timing of Training.
MTT is as simple as it sounds: timing your training to be heavier or lighter at certain times of your cycle to build the most muscle.
As you probably suspected, the female body is better at building muscle when estrogen and testosterone levels are highest, in the days leading up to and including ovulation (the follicular phase). The female body isn't as good at building muscle when progesterone is dominant in the weeks after ovulation leading up to menstruation (the luteal phase); in fact, training a lot during the luteal phase may even cause you to lose muscle!
I learned that consistency isn't actually the most important factor, but rather, timing of training. No need to push yourself during that late luteal phase-menstruation stage when you just drag your feet to the gym.
The general prescription for MTT is to work out good and hard on cycle days 1-14 when estrogen is high, then taper off as progesterone takes over and estrogen falls on cycle days 15-28. This is based on the standard 28-day cycle with ovulation on day 14, which is definitely not how most people's cycles work. I'll discuss how Fertility Awareness helps you use MTT to your best advantage in a minute.
I find it fascinating how the rise and fall of different hormones over the course of the cycle have an effect on training. As Stijn explains in his article,
Estrogen and testosterone, both at high levels in the follicular phase, have an anabolic effect, meaning they build muscle
Strength peaks around ovulation, and fluctuates about 10% during the cycle
Progesterone has a catabolic effect, meaning it breaks down muscle
Scheduling the bulk of your long, intense workouts for the follicular phase, while doing fewer and lighter workouts in the luteal phase, appears to be the best system for building and maintaining muscle. Taking a break from heavy training in the luteal phase doesn't seem to have the effect of erasing your progress; instead, it seems that it actually helps re-sensitize your muscles to the more intense stuff you'll do in your next cycle, ultimately preventing you from hitting a plateau and allowing you to continue to improve.
Now for a super important point! In order to take advantage of MTT, you'll want to know exactly when you have all that estrogen in your system to put in the intense workouts that will build the most muscle. Just as important is knowing when progesterone takes over so you know when to cool it and allow your muscles to enjoy their vacation without getting eaten up by progesterone.
Counting days on a calendar and assuming ovulation on day 14 isn't the way.
The trick is Fertility Awareness!
This simple daily practice involves checking 2 physical signs that your body gives you. By checking these signs and charting them, you'll know exactly what your hormones are up to and when the prime time for getting buff occurs each cycle.
Some people have peak estrogen around day 14, and others have it around day 20. Even people with a 28-day cycle may not ovulate around day 14, but day 10, or day 17. For folks with longer or shorter cycles, their estrogen peak will occur even farther outside the standard Day 14 time.
A Fertility Awareness chart showing exactly when peak estrogen occurs; on this chart, it's between cycle days 10 - 18.
These 2 signs of Fertility Awareness alone are the most accurate signals available to tell you where you are in your cycle - way better and cheaper than any test, app, or device. Take the guesswork out of the game and let your body show you what's up.
Fertility Awareness can help you get buff by showing you exactly what your hormones are doing so you can schedule your workouts for optimal fitness gains. So far this system is working great for me and I love training around my cycle!
Check out Stijn's whole article. It's jam packed with visuals and details about how MTT training works. He also gives a great explanation for how this training applies to women taking different types of hormonal birth control.
Using my follicular phase to buff up! Also, can you see what's on my shirt?