Eventing combines dressage, show jumping, and the horse version of cross country into one sport. This combined training is based on the old military tests of the cavalry where the rider's life depended on the horse listening to what the rider told it to do. Cross country makes this sport different from the other equestrian sports. It requires the horse to canter at a high speed over solid and interesting jumps. These jumps may be logs, stone walls, water, ditches, or banks. The cross country course is very long, and at the Olympics it may take as long as 10 minutes to complete the course.