Re: 400m time guidelines
I've run for years and done intervals likewise. At my best I never did less than about 1:40. And that was while I was running 40 km a week! I'm just slow but I'm not untrained. My RHR is in the 40's.
I had someone tell me on another messageboard that it was pointless me doing speedwork when I could only run 6 min kms. I was not amused. Some of us can't help it. I enjoy my runs and I'm far fitter than most people.