Cross country running has the highest injury rate of all high school sports. The injury rate is even higher for girls than for boys. The extremely high injury rate is due to runners having to train and compete in the same week. Most coaches know that you have to run very fast in workouts to run very fast in races and the fastest way to train is interval running or fartlak, a series of very fast short bursts of running interspersed with slow jogging.

The workout is done by running very fast one day, making your muscles feel sore the next day, and not running fast again until your muscles feel cool. The faster you run, the longer it takes to recover. Most high school runners take at least a week to recover from pain caused by a race. Usually the coach takes them to a race on Saturday and asks them to do intervals on Monday or Tuesday, before they recover from the race. Either they get injured from that interval session or they injure themselves running the next Saturday, before the leg muscle has recovered from the interval session. If they run fast in races and slowly all the time in practice, they are less likely to be injured, but more likely to run slower in races.

The most effective way to prevent injuries is for a coach to establish at least two teams. Let each team run every other week, so that each runner runs one week and fast trains twice the next week.