Some marathon runners forget over time just how much they hurt, depending on how much they enjoyed the race.

http://well.blogs.nytimes.com/2015/06/03/forgetting-the-pain-of-exercise/?smprod=nytcore-iphone&smid=nytcore-iphone-share

The best time to drink coffee is actually between 10-12 noon and the next window is from 2-5pm. Drinking coffee at these times does not interfere with the natural energy cycle your body produces. And by waiting for the ideal times you also minimize building up a "tolerance" to the caffeine. Read the story to see how important cortisol is to the process.

We can figure out better times by knowing how our bodies produce hormones.
http://wapo.st/1I1K0G1