Well, I don't know if I've ever heard that particular formulation before, but I have become all-too-well aware that getting frustrated *can't* help me, but *can* hurt me, by making me try to "push my boundaries" further that my legs, hips, or heart are able to.

What got me semi-frustrated yesterday was that I did this on two days rest, figuring it'd be best to give my body some time to rest up after three days in a row of workouts. I was kinda-hoping for five minutes of running per interval, with a surprisingly pleasant number of intervals before I had to ease up.

I was kinda-sorta-not-too-proud of my ability to recognize that I just wasn't going to get the workout I wanted, and to change things around to the workout I was able to do.