Reining is the fastest growing sport in the Equine Industry. Reining is a judged competition designed to show the athletic ability of a ranch type horse in the confines of a show arena. The governing body of the sport is the National Reining Horse Association (NRHA). NRHA defines reining as: "To rein a horse is not only to guide him, but also to control his every movement. The best reined horse should be willingly guided or controlled with little or no apparent resistance and dictated to completely. Any movement on his own must be considered a lack of control." There are ten NRHA approved patterns containing required maneuvers, including small slow circles, large fast circles, flying lead changes, roll backs over the hocks, 360 degree spins, and the very exciting sliding stops.

In reining all horses are created equal as they all begin the competition with a score of 70. The horse can either plus or minus 1/2 to 1 1/2 points on each maneuver in the reining pattern. The above statement is the basis of all scoring with "credit being given for smoothness, finesse, attitude, quickness and authority of performing various maneuver, while using controlled speed, which raises the difficulty level." Penalties of 0 to 5 points also accrue for incorrect maneuvers, and going off pattern will result in the dreaded Zero.

In 1998 Reining became the sixth discipline approved by the United States Equestrian Team. In 1999 Reining made its debut at the Bayer/USET Festival of Champions, the first time a western discipline has been included as a competitive equestrian sport. The next goal is to be approved as an Olympic Event.