I did 4 miles on the W&OD rail-trail this morning, but looking at the forecast, I was afraid that it would be pouring rain all day tomorrow and I wouldn't want to run in that. So I went out just before sunset and did another 3 miles on the track to complete my personally-assigned weekly minimum mileage this week. Both times I was averaging a comfortable 12 min/mile pace (or .0833 miles/min).
I did something new - counted my right footfalls for one minute to determine my comfortable running cadence. I repeated it four times - so counts of 86, 84, 83, and 83 average out to a stride frequency of 84 strides per minute.
Now since velocity (.0833 miles/min) equals stride length (in ? miles/stride) times stride frequency (84 strides/min) , then stride length equals velocity divided by stride frequency.
Doing the math, and converting to feet, gives me a calculated average stride length of 5.23 feet per stride when I'm running comfortably at that velocity. Cool!
Of course, any time I increase speed, either stride length or stride frequency, or both, must increase, by definition, so these will vary depending on how fast I'm running.
Additionally, this tells me that my lowest optimal cycling cadence is somewhere about 84 cycles/minute. Or slightly higher, since your leg is somewhat shorter when it's bent when cycling, making a shorter pendulum with a higher natural frequency.
Or maybe not. I may possibly have had a teensy bit too much of the excellent Riesling that we had tonight with the tuna steaks that I grilled for dinner. Yum!