Isn't it all about training the body to run at race pace - and do things like accelerate, jockey for position etc. - when you are in heavy oxygen debt? Repetitions at 800/1500 pace with short recovery - ie much less than complete recovery is the way to go. As Harry Wilson, Steve Ovett's coach, explained 4x2x400 fast with 30 sec between runs and longer between sets was a better session for an experienced runner than the standard 8x400 with 60-90 sec rest. Unless the run is quite long, eg at least 500m at 800 pace, having complete recovery will not prepare the body for the demands of racing/coping with a large oxygen debt