The takeaway I get is that it increases perseverance. So basically, "doing something physically unpleasant every day increases ability to push through/withstand other physically unpleasant events" is my big takeaway. Seems pretty straightforward. Not necessarily novel, especially when you add in the exercise portion.
I think there's some value to pushing yourself harder than the minimum to be comfortable and survive. But I don't think that's a eureka.
