1000 meter running intervals...well sort of

I measured off 6/10 of a mile on a flat around 1.5 miles from the house to do my 1000M intervals since the track is closed (wintertime brrrrrr). The first interval went well in 4:00. I really didn't feel that my HR was high enough (like I should have been working harder). Second interval I tried to pour more power into the interval and felt a muscle in my left inner thigh tweak. I shut it down and ended with an endurance run.

Ran 45 minute with a average hr of 157.