I haven't focused on the XTERRA world for a few years, but still do one or two a year. I hope to get back to Utah and Maui next year as both courses are fantastic (and hard).
For me, I would train pretty similarly to my normal tri schedule with mainly masters swim, and several run sessions a week (long, speed/hills and a hard off the bike, as well as running on rough trails every other week). For the bike, I would do 1-2 very technical MTB rides (pure focus was on the technical side) and then did a hard VO2 ride and lots of threshold work on the road/tt bike depending on the time of the year.
The swim is important, more so than in regular triathlons as many courses are tight and if you don't get out the water early, it is hard to pull back the leaders (especially in Maui). Some courses, like Utah and a few here in TX as well as the old Vegas course had lots of room to pass so the swim plays lesser of a role.
Just writing this makes me want to get back out on my MTB!
Jack
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