With a nod to the Running Laminator and a book I picked up "Run Faster", I changed my workout for today to a tempo run. My goal was a one mile warmup, 4 miles at tempo pace (which I defined at heart rate 85-90% (basically between 160 and 169 BPM), and then a half mile cool down. I ended up running the tempo pace at 7:30 on the treadmill, which my Garmin footpod had at 7:00 or so.
At the 7:30 pace on the treadmill (which Garmin had at sub 7:00), my heart rate was in high 150's and climbing. But I don't care what my heart rate monitor said, I knew was not going to make 4 miles at that pace. When I ratcheted down the pace to 7:45 on the treadmill, I hit a sweet spot -- comfortably hard. And my heart rate was perfect -- comfortably in 160's. I decided to extend the tempo portion to 4.5 miles, and shorten the cool down to 0.75 or so. Ended up with a 5.75 mile run on treadmill. Of course, Garmin had it my run both longer and faster than what treadmill measured. Unfortunately, I accidentally turned off my Garmin when I switched from tempo pace to cooldown mode, so I have no HR data for the last 6 minutes of the run (which I ran at 9:40 pace or so). Final data from the treadmill:
5.75 miles at 8:03 average pace
Garmin had it at 6.25 miles at 7:52 pace
I sweated like crazy, fwiw. I normally sweat a lot, but tonight was ridiculous.
It was a tough workout -- one of the harder ones I have done on a treadmill. I speculate that a tempo run on a treadmill is easier than one on the road because on the road it is up to the runner to maintain the pace. On the road, I know it would have been a challenge to go that fast --and maintain the pace. So, overall a success.