In the lead-up to the 1996 Olympic Games held in Atlanta, Georgia, numerous studies were conducted to measure the intensity of exercise during the cross-country phase of longformat three-day events. These studies were focused on the effect of heat and humidity during competition. In each of these studies, heart rate (HR), and plasma lactate were used as indices of exercise intensity.
Three-day eventers in the United States typically end their competition season in October or November. At that point most horses are taken out of training and allowed to rest throughout the winter. Many eventers based in the eastern United States migrate to Florida, North Carolina, or South Carolina in January where they resume training for the upcoming season. These horses remain there in training until early to mid-April when most return north to enter competitions throughout the spring and summer. During February, March, and early April, these horses compete in three-day events throughout the Southeast.
Exercise intensity has not been previously quantified during these early-season shortformat three-day competitions. Therefore, Kentucky Equine Research conducted a study to measure the intensity of exercise in horses competing at several levels in horse trials and three-day events during the early stages of the 2015 eventing season.