I guess it's good for your muscles and joints, just as it is good for scheduling. I never made my run yesterday, so I will probably make it up this evening. Those who commented that I had that option are right to note that training schedules are meant to be flexible, and as long as I get the miles in, that's the most important thing.
Thankfully, I'm done with class on Fridays at 2, so I can go home, maybe nap, and go for a run this evening. I've never been so thankful to see a week come to its close (of course, most of the weekend needs to devote itself to reading papers, but at least I can do that at home). Have a good weekend everyone!