This morning MAF helped rescue me from a crappy workout. It was too icy to run outside (the roads in Parker are horrendous), so I hit the treadmill for an 8-miler at MAF. During the first mile my heart rate (HR) unexpectedly spiked to 167 without warning. As GZ pointed out, that could have been related to static or whatever, since Denver is so damned dry. Or maybe my HR just spiked since I was, after all, feeling quite rough from two runs and a weight session the previous day (plus crappy sleep on Wednesday night). In the moment, though, my only reasoning for the spike--again, I was feeling rough--was that I was dragging from yesterday's training. So I slowed down, and even stepped off the 'mill for a few seconds, and got my HR back down to MAF range. Once back in range, I settled into a nice pace for the rest of the way, clocking 8 miles in 1:01:49. During the last few miles I had to slow my pace a bit to stay in MAF. Average HR was 138. Perfect.
Without MAF, I would have tried to push through feeling like crap and would have only felt crappier with ever step, digging myself into a hole. We often don't recognize the holes we're digging, but we dig them with one shovel-ful at a time and this morning, had MAF not reigned me, I would have started digging that hole and suffered the consequences for days. Instead, I let MAF pull me into the pace I needed to be in. That is the beauty of MAF! It's not a predetermined pace and it's sure not LSD (long, slow distance). If you're feeling good, then your pace is going to be good. If you're feeling rough, like I did this morning, then MAF is going to "make" you run slower. It's a personalized approach to training, and I love that.