1km intervals

First time I've done a session like this and I was pleasantly surprised. My times were 3:32, 3:39, 3:40. With the warm up and cool down total distance was 7km. I ran them on a 1500m loop, running the first km and then walking the last 500m as recovery.

I wasn't prepared for how much more havoc it wreaks on your gut! but I will be next time. I think I'll try them in a straight line next time too, and hopefully do 4 or 5...