Treadmill 2x2 Mile Intervals

I hadn't done these in a while...

About a week ago, I hit the treadmill for a simple 2x2 mile interval workout. I think the last time I did this workout on the treadmill was about 2 years ago where I started at 9.8 mph and slowly creeped up. That first interval back then was too slow as I ended up running 11:50 and 11:24.

So I knew I'd start this round of intervals faster than 10 mph. I was just consistent for the first 2 mile interval starting at 10.2 mph and speeding up 0.1 mph every 1/2 mile (10.2 mph through 10.5 mph):

2:57, 2:54, 2:53, 2:51 = 11:36

That felt OK, so I planned to start the 2nd interval a bit faster. I walked for 0.2 miles which was a 2:34 rest (well, technically walked about 0.15 miles before speeding up the treadmill to get up to speed by 0.2 miles). Then I cranked it up to 10.3 mph and planned to speed up the same as the first interval (0.1 mph every 1/2 mile), but I sped up twice between 1 and 1.5 miles, and twice between 1.5 and 2 miles to end at 10.8 mph:

2:55, 2:52, 2:50, 2:46 = 11:25

Here was the "graph" on the treadmill after I was walking for a moment after my 2nd interval:

Two big "plateaus" of 10 mph speed.


Normal pace and HR graphs.

Like I mentioned at the top, it was Feb 2021 when I last did this on the treadmill in 11:50 and 11:24. The last few times I did this outside were in Oct 2022 in 11:43 and 11:49, Mar 2022 in 11:47 and 11:35 (SOLID times), and Oct 2021 in 11:43 and 11:48. Both of those Oct versions were after the TC 10 Mile and before a half marathon.

I can't compare the treadmill versions of this to outside versions, but I know I can go a bit faster the next time I do this on the treadmill. I can hit that last half of the final interval a bit harder.