I expect to be able to post a significant Q&A interview with Brant Best, personal coach of the new 100m freestyle world champion, James Magnussen, within the next couple of weeks. This should shed light which reveals their “state of the art” - quote Magnussen, swim training program which bares an astonishingly close resemblance to the concurrent concepts laid down in the lactate threshold thread as well as an actual attribution. Magnussen swam 47.6sec which is fastest ever for a man swimming in a textile suit, so we can call it a virtual world record. The time for 100m freestyle (especially when you take away the underwater glide time component following the entry dive) is very close indeed to what constitutes a world class time for the men’s 400m track sprint. Food for thought. Well, I’m off to the pool now. 
kk