Successful conditioning of the equine athlete is dependant upon several factors. Obviously, genetics cannot be overlooked, because breeding influences what the horseman has to start with, how long it will take to achieve some level of fitness and the extent to which problems may be encountered along the way. Genetics must also be considered in the selection of specific horses for specialized events. One reason is because the relative percentages of muscle fiber types in horses vary somewhat between breeds. Consequently, the competitive hopeful must be selected with regard to expected suitability for the event or type of activity. Genetic make-up must also be considered along with the early environment to which a horse is exposed, because these two things will affect any person's ability to train the performance horse. Without a doubt, genetics and environmental influence combine to produce horses that vary in attitude and responsiveness toward work.

Training (behavior modification and learning) is an important factor that must be considered in a conditioning program. The level of fitness being reached will impact the rate and success of a progressive training program. Fitness must keep pace with increased learning in order to prevent fatigue and lameness from negatively affecting a horse's ability or willingness to learn. In race horses, sprint work is essential in conditioning two-year-olds, but they are not mature enough, mentally, to handle very much of it. Level of training also impacts the amount of time required to condition an athlete. Conditioning of the untrained or poorly trained horse will require more time than developing fitness in a seasoned horse that has learned the maneuvers and conditions associated with a performance activity. As a result, conditioning programs must be initiated with ample time set aside to also give a horse the proper training needed.

Age and skeletal soundness are two factors that play a major role in conditioning. Younger individuals possess less blood volume and do not have the oxygen carrying capacity that older, mature horses have. Exercise also delivers significant concussion and strain to the bone, and this is likely influenced by both gait and speed, among other factors. The skeletal system of a performance horse adapts to exercise or the lack of exercise by forming or removing tissue. During the remodeling process, the bone experiences a period of time when its strength is actually decreased. In young horses, the skeletal system must lay down new bone in response to both growth and exercise. Young race and performance horses often have a high degree of stress placed on their skeletal systems. Since the horse's skeleton does not usually reach full maturity until four years of age, injuries to the bones can and do occur. Wastage rates in the population of young performance horses seem high, and both training and conditioning programs are challenged to minimize lameness through more effective exercise and behavioral modification techniques. Even in older horses, proper bone maintenance must occur, because lameness represents significant economic loss and causes conditioning to be slowed or stopped.

Horses often experience acute fatigue during a variety of performances. Therefore, they must be conditioned and fed in a fashion that will delay the onset of acute fatigue. To perform well, a horse must have access to sufficient energy which provides the fuel needed to accomplish the task. This energy must be accompanied by adequate amounts of other nutrients that maintain the horse's skeletal integrity and promote muscular contraction/relaxation.