3x1 Mile Treadmill Intervals

After 2 weeks of all outside runs, we got a small dump of snow and some cold temps later last week:

Screw this. I'm ready for spring.

So I hit the treadmill to close out last week. I settled on some 3x1 mile intervals in the basement.

I failed at this workout about 6 weeks ago and I ran it fast in early Decemeber. I didn't look back to any old times as I was just trying to get in some hard running without trying to beat some sort of PR.

I decided to take off at 10.5 mph and speed up a few times in the first interval. I ended up speeding up to 10.6 mph at 0.3 miles in, and up to 10.7 mph 0.6 miles in. I started the 2nd interval faster yet at 10.8 mph and sped up similarly. And then in the 3rd interval, I started at 11.1 mph and sped up at 0.3 and 0.6 miles in like in the first 2, but also sped up at 0.8 as well, so I ended at 11.4 mph. Here's what I ran (in half-mile splits):

[Our treadmill gets up to speed slowly, so I started speeding up aroung 1:45 into my walking rest so that I'd be running at my "interval pace" (or very close to it) when 2/10s of a mile clicked past.]

1.5 warm-up (7.7-8.2 mph): 3:54, 3:48, 3:42
0.2 walking: 2:24

10.5 mph for 0.3, 10.6 for 0.3, 10.7 for final 0.4: 2:51 + 2:48 = 5:39.6
0.2 walking: 2:19 (speeding up around 1:45)

10.8 mph for 0.3, 10.9 for 0.3, 11.0 for final 0.4: 2:47 + 2:42 = 5:29.8
0.2 walking: 2:18

11.1 mph for 0.3, 11.2 for 0.3, 11.3 for 0.2, 11.4 for 0.2: 2:41 + 2:38 = 5:20.5

It wasn't until after the workout that I looked back to when I did it in December and saw that I started at 10.8, 11.0, and 11.3 mph that time, so this was decently slower (the 3 intervals being 8, 4, and 4 seconds slower this time, which I guess isn't a CRAZY difference - it's funny how those changes in mph SEEM like they'd do more to my splits, but it's only a few seconds when starting a few tenths of a mph faster).

Pace...


... and heart rate.


Sweaty treadmill part-way through my cooldown.
Intervals labeled in Photoshop in red.