I decided to try something different for my run, today.
Here's what I NORMALLY do:
Each lap is just shy of 1/3 mile.
There's a bit of a hill on roughly both sides of the lap, practically dividing the lap in half -- one hill up and one hill down. The up hill is uncomfortable to run. I'd guess it's 30 to 40 yards long.
So, normally I run at a moderate pace until I get to the up hill. Then, I walk up that and then continue walking until I feel somewhat recovered. Then I run moderately until I get to the hill again.
Today, I wore a heart rate chest strap monitor, with a readout on a watch.
I ran at what felt like a very fast pace (though you still couldn't call it a sprint) until I got to the hill. My heart rate at that point was typically up or down a couple from 165.
Then I'd walk until my heart rate dropped to 135 (on the first lap -- it never got that low again after that, so for all the later laps, I walked until it hit 140).
Then I'd run as fast as I thought I could handle it until I hit that hill again.
Each lap required a longer walk before my heart rate calmed down.
What really surprised me was that at about the 1.5 mile mark, my heart rate would drop to 140 while my breathing was still quite heavy and out of control. IOW, I was still gasping for breath at the time my heart rate suggested I was ready to start running fast, again.
I'm going to do this type of running every so often -- not sure if I'll alternate every other one or what. But, I feel this is a good way to improve my recovery time and increase my speed and endurance.
I was a bit disappointed -- but not really surprised -- that running faster and walking until recovery resulted in a significantly slower time for the 2 miles.
I did 2 miles in 25:12.
For comparison, my last run (4/26) was done in 22:28.