September 17, 2019 =========
☆ exertion 大変な努力
If you exert yourself (a verb) you work physically (or mentally) hard to do something. So, exertion is the noun of this meaning effort, exercise, strain, and struggle for example.
Continuing on from yesterday, about cortisol, when you put in a lot of physical exertion in exercise, the body produces cortisol. So, you might here doctors say, “Exercise, but not too much.” What they mean by that is there is a good level of exertion that will allow your body to be fit and healthy, but not produce too much cortisol.
I’m trying to run more regularly, but without too much exertion, so that I can run longer distances again. Hope it works!