Ergogenic aids in the performance horse

An ergogenic aid can be used to describe any agent, which can increase or improve work production (or exercise performance), resulting in an increase in speed, endurance, or strength. Such aids can be classified as psychological factors; mechanical or biomechanical factors, including improved equipment; chemical or pharmacological agents (e.g. drugs, such as anabolic steroids); physiological improvements (including most importantly those obtained through training) and finally nutritional supplements. Nutritional supplements in particular may improve performance through reducing interruptions to training that minor illnesses and infection can cause, or shorter recovery from a competition or more commonly through provision of increased mechanical energy for work, and/or a delayed onset of fatigue. Although many substances theoretically have ergogenic properties, only limited scientific evidence is available, in the horse, to support the postulated ergogenic effects of most of the products currently on the market. Manufacturers should be encouraged to undertake appropriate scientific trials to support the claims made for many of the products and consumers should be encouraged to ask for evidence in the horse before purchasing. In some areas, the boundaries, between what is and what is not acceptable, are blurred by the fact that many ergogenic aids are found naturally in the body. In this review, the evidence for and against various postulated nutritional ergogenic aids, including creatine, carnitine, oil supplementation, amino acids and â-hydroxy-â-methylbutyrate (HMB), with particular reference to the horse, is examined and discussed.