Similar thing happened to me at one of our club speed sessions, new boy joined who was built more like a rugby player. I kept up with him on the first interval but then got completely blown away by him, I was a little upset until I stalked him on Runbritain and saw he has a 14:40 5k and 32:01 10k to his name :D
oof, I'm am sure that I am physiologically unable to run a 5km sub 15. Probably unable to do a sub 17. I would hope that if I trained, eat, rested and conditioned myself like a pro I could run a 17 something. This is based on absolutely no experience and about 30s consideration.
Similar thing happened to me at one of our club speed sessions, new boy joined who was built more like a rugby player. I kept up with him on the first interval but then got completely blown away by him, I was a little upset until I stalked him on Runbritain and saw he has a 14:40 5k and 32:01 10k to his name :D