My son’s been wanting me to try this workout he’s been doing lately where he does a 5-minute warmup jog at 5 mph (12 minutes per mile pace), then 1 minute at 6 mph (10 min. pace), 1 minute at 7 mph (8:34), 1 minute at 8 mph (7:30 pace), 1 minute at 9 mph (6:40), 1 minute at 10 mph (6:00), then comes back down, 1 minute at a time, until he gets to another 5 minute cool down at 5 mph.
Since I’m slow he suggested I go up in .5 mph increments. But I really wanted to do whole numbers, at least on this first experiment, so to give myself more rungs on the ladder I started at a slower warmup pace: 4 mph, or a 15-minute pace.
This is obviously really slow, but I’ve done a fair amount of jogging at this pace with our 12-year-old the last few months, so I knew it could be done – and that it would feel good after testing my limits.
It was weird how much faster a 12-minute pace felt than usual, coming up from such a crawl. Same with 6 mph, which is usually a pretty comfortable pace for me. I knew I could do 7 mph for a short time, having done a minute or so at that speed on a treadmill in the past, but I didn’t know how 8 mph would go, having never attempted that.
Well … now I know I can hold a 7:30 pace for at least one minute. It wasn’t easy, and in fact it made me so nervous I held onto the bar part of the time. But I did it. And the most amazing part (to me) is that it wasn’t sandwiched between recovery jogs or walks but by 60-second intervals at what I usually consider my fastest gear.
The cool part was how much slower each speed felt as I came back down. That was the most relaxed 7 mph treadmill minute I’ve ever done. And 6 mph actually felt slow (which it is to many runners, I realize, but not to me).
By the time I got back down to my 4 mph cooldown, it felt almost ridiculous. So I bumped it back up to 4.5 mph (a 13:20 pace) to finish out the 17-minute workout.
It will be fun to try this again (or some variation) now that we’re getting into treadmill weather. I need to keep training outdoors for the Huff, obviously, but it was fun to push my boundaries and see what I could do.
90in9 
I love that realization moment where I find out how slow slow really was – and that I can do better. Those moments are fewer and farther between nowadays, but that makes them even better. Nice work.