How hormones affect women in training.
In her book, “Roar”, Stacey Sims reminds us that, “Women are not small men”. For both men and women hormonal fluctuations cause a reaction in the body that can affect your training and nutrition. But when it comes to hormones, clearly women are different; we go through cycles during our life, our menstrual cycle, the pregnancy cycle, and the menopause. And yet to date, most scientific research on the effect of hormones and sports performance has honed-in on men between the ages of 18 and 30! So how do hormones affect women in training?
In this post I am focussing on what happens during your monthly cycle. I encourage my female athletes, to track their cycle, to make them more aware of the hormonal changes that happen each month. You can use an app like Hormone Horoscope, or monthly info to keep tabs on where you are in your cycle. Even if you don’t use it to inform your training, I still feel it is a useful thing to be aware of. If you’re not convinced then have a read of this article.
Let’s talk about it
I’ve found that some women are keen to get in tune with their cycle, and others just don’t want to talk about it. The messages that we are given in the media are, that it shouldn’t stop us from doing anything. Periods are an inconvenience that we need to try and ignore or take pain relief for. Its great that we can carry on with our lives when we have a period. But we also need to be aware of the effect that our hormones will be having, so that we can better understand our motivation levels, and our training and nutrition needs.
First let’s have a look at what happens every month in a menstruating female.
What actually happens?
A women’s menstrual cycle lasts anywhere between 21 and 40 days, and it can also be outside these ranges. It is pretty common for there to be variability from one month to the next in the length of your cycle. As long as it’s not wildly out every month, then it’s normal for this to happen. The picture above assumes that you have an “average” 28-day cycle, (very few women actually do have a cycle this length!)
The first half of the cycle (days 1-14) are from the day that you get your period until the day that you ovulate. Which I’ll refer to as the low hormone phase. The second half of the cycle (days 14-28) I’ll refer to as the high hormone phase. The day that you ovulate is not necessarily day 14, it is usually around midway through your cycle.
During the low hormone phase, and just after you get your period, oestrogen starts to rise. In this half of your cycle you are more able to make strength gains, and your mood will probably be better. You can follow general advice for nutrition and hydration because you are physiologically more like a man at this point in your cycle. If you have your period on race day, its not such a bad thing. There are numerous stories of women performing well when they have their period. In Victoria Pendletons’ book, “between the lines”, she refers to winning races when she had her period. From personal experience, I have found that it does not really impact my performance.
In the second half of your cycle, progesterone starts to rise, which may make you feel lethargic. It gets harder to recover, and sessions that felt easy a few days ago, now feel harder. You may have cravings, because your metabolism increases slightly, due to increased basal temperature, and you may also feel bloated as your body retains water.
What can I do about it?
In one study it was found that amongst women trying to lose weight, those who followed an exercise/nutrition plan tailored to their menstrual cycle lost more weight than the ones who just restricted calories. For best performance, you need to pay attention to the timing of nutrition and hydration, particularly in the high hormone phase. Stacy Sims recommends 10 to 15g of protein and 40g carbs at this time before any workout lasting longer than 90 minutes, and after sessions. Also hydrating well, and preloading before long, harder races with salt would be beneficial. During the high hormone phase your blood plasma volume is lower, which is why those hard sessions feel more challenging. Your blood is essentially thicker which makes it harder to get oxygen to your muscles, and as your core temperature is increased you will feel the heat more, and therefore need to ensure that you hydrate and keep cool, especially in hot weather.
I’m looking forward to seeing future research in this area, as more women take part in endurance sports, and become interested in making their training more effective. Watch this space!
I use the Fitr app with my female athletes to better inform their training and recovery, check my plans here