Chronic Illness & Data Science, n=1, blog on Medium by Nicola

If anyone has an account on Medium, they might like to invite Nicola here. (Perhaps she is here already.)

 

My own experience fit with her first observation, but not the two others. Though since she doesn't say how she tracks her period days it could be an inverse. My day 1 would be start of bleeding, I know others start at first day after bleeding or first day of ovulation. My heartrate is at its peak the day(s) before I start bleeding, before rapidly decreasing and then starts increasing again after ovulation. The difference can be up to 15 in a month.

I'm not familiar with her heart rate tracker, but with fitbit a higher level of activity would quickly give a higher resting heart rate, so activity could come before the heart rate change (she has a lag in her data so this might not be an issue). For me, I look at how heart rate varies form what I would expect. Right now it should be declining rapidly, and if it doesn't (go down by 2-3 beats per day) I am likely to take it easy. Yesterday it started out at 65 (a two point drop from the previous day), but when I came home from work it had krept up to 66 which it likely wouldn't have done had I been at home with the option to have my feet elevated while at my computer. The activity came before the HR change. I also know I've done too much if my HR does not decrease rapidly after exertion (if I have gone for a slow walk and it's been around 100-110, I would expect it to go down to 60-70, but if it stays at 80 then something is up... this will also likely influence my next day HR due to how fitbit calculates them).

There is increasing interest in the differences in the body during different phases of menstruation. In the follicle phase it is said the body is more capable of utilising carbohydrates for energy, while in the luteal phase carb utilisation is reduced while fat utilisation increases. This has translated to exercise research on what type of exercise should be performed in different phases, with explosive exercises being better in the follicle phase since quick energy from carbs is good both for training and recovery, and in the luteal phase longer less intensive exercises can be better.

This could perhaps point to clues in deficiencies to utilise one energy source over the other?

Another thing is the change in hormones and other compounds in the body, such as progesterone and arginine. Both are able to influence blood vessel dilation, and could potentially contribute to ortostatic intolerance (which again would change the heart rate on wearables). I wonder if heart rate graphs would look different for women with and without OI. A pattern is not seen in every study on periods and heart rate, and when it is it can vary a bit. Some get their peak around ovulation for example.

Added: The immune system also changes its activity during the menstrual phase, to accomodate a potential fertilised egg. Yet another thing that could contribute.

More studies please

Edited again: I know myself and other women in addition to Nicole that report to feel worse during ovulation and not pre menustral bleeding. I'm not sure there is a normal here, as popular culture has sort of cemented PMS as what we get (and even then getting it wrong believing it is the actual days of bleeding not the days before... sigh.)