A menstrual cycle is an unavoidable monthly experience for many non-post-menopausal women. Personally, my period usually brings a bad headache the day before and the first day of my menstrual cycle, and my fatigue is far higher. I have always adjusted my workouts slightly during the beginning portion of my menstrual flow because I know I’m not going to want to run my farthest run of the month on the day I typically have a headache and feel far more tired than usual. However, I came across an article that looked at the connection between estrogen and performance and wanted to share it! The study assessed how estrogen impacts muscle damage after endurance exercise in 10 physically active women with normal menstrual cycles (Williams et al., 2015).
The women completed 60-minute treadmill sessions at 60 to 65 percent maximal intensity during the phases of their menstrual cycle when estrogen was at its lowest and highest points. Their findings showed less exercise-induced muscle damage when elevated estrogen levels were present, meaning higher estrogen levels play a protective role in reducing delayed onset muscle soreness and inflammation (Williams et al., 2015).
What exactly does this mean? It is ideal for women to program their more challenging workouts when their estrogen levels are higher. It’ll help reduce muscle soreness and inflammation, ensuring you bounce back from a tough workout quicker. If you schedule a hard workout on a day where your estrogen is lower, taking a non-steroidal anti-inflammatory drug may help with muscle inflammation (Williams et al., 2015).
In addition, strategically planning workouts when estrogen is higher helps lower blood pressure. A different study examined whether the menstrual cycle affects blood pressure during dynamic exercise for 11 women with no health issues (Min Choi et al., 2013). The participants performed mild to moderate cycling sessions during the early follicular menstrual phase when estrogen is lower and the late follicular phase when estrogen is high, after which their blood pressure was taken. The study found that blood pressure during dynamic exercises, such as cycling, was higher during the early follicular phase than in the later follicular phase, meaning higher estrogen levels helped reduce blood pressure (Hyun-Min Choi et al., 2013).
So, when exactly is estrogen lower and higher each month? Estrogen begins low at the start of your menstrual cycle and increases in concentration during the first week. Your highest estrogen levels exist right before ovulation. If ovulation does not occur, estrogen begins to decline, leading to the start of your period. So, estrogen is the lowest right before your menstrual flow begins and the first few days after your cycle ends. These are the days I would highly recommend avoiding overly strenuous workouts. Can you still work out? Absolutely! But these might not be the best days to run your furthest distance or go for your bench press PR. These workouts would be better scheduled in the middle of your cycle when your estrogen is high. During the week of your menstrual flow, it is better to opt for more reps at a lighter weight, or go for a run or ride that is in the low- to mid-mile range. Use this week as more of a recovery week, so you can increase your strength and miles as your estrogen revs up later in the month.
I do also want to note that because estrogen plays such a crucial role in women’s overall health (I’m talking about everything from cardiovascular health to bone density) if you ever have concerns about your estrogen levels, I would highly recommend making an appointment to see your doctor. Symptoms to look for include a diminished menstrual flow or one that stops altogether, accompanied by an unusual level of fatigue.
I hope this helps as you plan your workouts throughout the month!
Hyun-Min Choi, Stebbins, C. L., Hosung Nho, Mi-Song Kim, Myoung-Jei Chang, & Jong-Kyung Kim. (2013). Effects of ovarian cycle on hemodynamic responses during dynamic exercise in sedentary women. Korean Journal of Physiology & Pharmacology, 17(6), 499–503. https://doi.org/10.4196/kjpp.2013.17.6.499
Williams, T., Walz, E., Lane, A. R., Pebole, M., & Hackney, A. C. (2015). The effect of estrogen on muscle damage biomarkers following prolonged aerobic exercise in eumenorrheic women. Biology of Sport, 32(3), 19