What activity primarily involves riding horses for recreation?

The activity that primarily involves riding horses for recreation is horse-riding. This activity is focused specifically on the enjoyment and leisure aspect of being on horseback. Horse-riding can take many forms, including trail riding, leisurely rides through nature, and even recreational competitions, all centered around riding for pleasure rather than competition.

In contrast, horse-racing focuses on competitive events where horses are raced against each other, making it primarily a sport rather than a recreational activity. Equestrian training is more geared towards preparing both horse and rider for competition and technical skills, rather than for fun or recreational purposes. Hurdle jumping involves an event where horses and riders jump over obstacles, which, while thrilling and engaging, is also competitive in nature and not primarily recreational.

Thus, horse-riding stands out as the activity most closely tied to recreation, allowing participants to enjoy the companionship of horses and the experience of riding without the competitive pressure found in the other options.