I'm not going to sugar coat this or tip toe around this often taboo topic: but sometimes being a woman sucks.
As a runner, we deal with things our male counterparts never have to concern themselves with. For example, there is an entire science to choosing the right sports bra: one that will properly restrain your chest while hopefully still providing comfort, and not leaving you with chaffed rib cage and raw shoulders. Chances are when you find that perfect combination, you will end up shelling out as much cash out for it as you paid for your last marathon entry.
And then there is the topic of periods.
Ahh the wonderful, unpredictable, menstrual cycle. Sure, this feat of human anatomy should be celebrated, as it is a reminder of our awesome ability to bring life into this world, to carry on the human species. But let's face it: periods are not fun. In fact, sometimes they are downright miserable, leaving us in a lot of physical pain and discomfort. On those days it would be easy to justify skipping a training running for curling up on the couch in a pair of baggy sweatpants, blaming our period for what we can only assume would end up being a less than stellar run.
But how do our periods really affect running? The answer might surprise you.
First, let's have a little refresher on the menstrual cycle as a whole. The first day of the cycle is the first day of menses, or when bleeding begins. Bleeding is usually complete by day 5 or 7. Days 1-14 are called the follicular phase. By day 14 or 15, ovulation begins with a surge in estrogen and luteinizing hormone. The following phase lasts until the last day (28 on average) and is called the luteal phase.
During the luteal phase, or the weeks leading up to your period, the hormones estrogen and progesterone are at their highest. The change in hormone levels cause a number of changes in your body, including (but not limited to) decreased sodium levels, a drop in blood plasma volume, and an increase in core temperature.
But what does this all mean?
The hormone levels before you get your period are more likely to negatively affect your performance. And here's how: A decrease in blood plasma volume means your blood will essentially be thicker, and therefore slower moving to the muscles both during exercise and recovery. Further, a decrease in blood plasma volume can slow down our body's natural sweat response, which will cause an increase in core body temperature, negatively affecting performance.
Once your period starts, specifically on the second day of bleeding, your estrogen and progesterone levels hit rock bottom. In other words, even though you may feel miserable, your hormone levels and core temperature are more similar to that of a male at this point than at any other point of the month. Pretty ironic, isn't it? From a performance standpoint, this means you are physiologically more likely to hit higher intensities with your workouts.
Further, running can help you get rid of those awful menstrual cramps. The increased blood flow from aerobic exercise produces natural pain relieving endorphins, and helps to burn the
prostaglandins, or chemicals that cause muscle contractions, which result in cramps. And those endorphins do more than just relieve physical pain: these mood affecting neurotransmitters have been proven to help uplift your mood and decrease stress. If you've ever found yourself crying over an otherwise not sad TV commercial while on your period, you can understand how beneficial these mood lifting endorphins may be.
So to sum up the topic of how your period affects your running: in short, it doesn't, at least not negatively.
Sure, you may feel crampy, moody, and uncomfortable, but from a training point of view you may be at your peak while enduring "that time of the month." So lace up your sneakers, run a few miles... and then grab that pint of Ben & Jerry's.