A bit tangential, but reading the above post reminded me of one of my running difficulties. I run with a friend who only knows pacing in "x minute mile pace". I only understand "x minute km pace", so often find myself trying to do the mental calculation whilst we run. This is obviously easy for 5 min km/8 min mile, but 4m 30s per km to 7m 15sec per mile is trickier whilst running.
It odd, I can't even remotely comprehend what 6min per mile, or 7 min per mile is, whilst I have a good feel for 3m 45 sec or 4m 20 sec per km is