I think some of us do races occasionally. I tend to play about 1-2 weeks of races at the beginning of a season and then get bored. The main thing is getting used to going as quickly as possible without dying. You also kill very few mobs pre-Ledge, taking only large packs, blue packs, etc. The idea is to be about 2-3 levels behind the zone level so you’re getting lots of XP. You also have to know typical zone layouts very well in order to get through them quickly.
There are some good guides around but a quick search hasn’t turned up anything… will come back if I find something.