Biathlon (Run/Bike)

[OakLeaf]

I've never done a du either and hopefully some of the duathletes on here will chime in ... but +1 to what Owlie said.

AFAIK you're right it's unusual to run first (unless it's a du run in conjunction with a tri, where your first leg is a run while the others are swimming, but then your last leg is a run too). I always thought the order of the legs in duathlon and triathlon was for safety reasons. But if that's the way your race is structured, I'd make sure you do your bricks in the same order of your race - the idea of a brick is to get your body used to the changes it will have to make when shifting from one sport to the next. So the cookie cutter training plans will probably call for you to bike first, but if I were you I'd do the run first in your bricks if that's what you'll do in your race.