Not, it's not really like mountain biking. The courses are usually 1-1.5 miles, and the races are done on time, like a crit, 60 minutes for elite, as low as 30 minutes for begginers. The courses usually start with a good road section, before going off onto grass, dirt, gravel, whatever. But the off-road stuff is all wide, not very technical, and fast, unless of course it's muddy. Then there's obstacles to run, like hills, mud/sand pits, and wood barriers.