Originally Posted by s.sciame
So curious to know how a TI coach trains for such a long distance by the way...
... truly depends on whether one wants to book it real fast or not. For example, given neutral conditions (not favorable, not dis-favorable), achieving 5hfat (about 1:30/100m) would require, from the little bits I know of Shinji, a volume of 20k/week for at least 16weeks. In a pool, marathoners often time trial over 25k, which is usually done below 6h without too much effort. You need some of these long time trials as well to "optimize" the result over a marathon. But then, not everyone dives in at the start to swim their maximum best time. If just finishing the event is the main goal, one could live on a 10k/week diet and still enjoy the venture.