I long ago figured out that even simple math is beyond my mental capacity once I pass the 20 mile mark in a run. With a glance at my Garmin I can easily determine stats like my current pace, average pace for the current mile and my average pace for the entire race. If I'm off target though, I find it very hard to calculate how much I need to speed up or slow down in order to get back on track.
I tried to do exactly that calculation late in the Marine Corps Marathon and ultimately gave up. I finished the race with a PR which was awesome but just missed the goal I had set for myself and couldn't help but be just a little disappointed.
I would hate to fall short of my responsibility as a pace leader this weekend because of a math error. This wrist band, courtesy of Marathon Guide, should help.
