Ergogenic potential of nutritional strategies and substances in the horse

In man, it has been suggested that nutritional ergogenic aids are far less efficient, in general, in improving physical ability than an appropriate training regimen. This is also possibly true for the horse. Athletes who are training at levels close to their upper limit, however, require relatively large increases in training effort to achieve even a small increase in performance, significantly increasing the risk of breakdown. Very small variations in performance, whether achieved through significant increases in training effort or by addition of a nutritional supplement, could make the difference between finishing first or in the middle of the pack. The comparative ease of taking a nutritional supplement, compared with the significant increase in training effort required, explains why there has been such a demand for nutritional ergogenic aids. These may result in increased mechanical energy for work, and/or a delayed onset of fatigue, or improved neuromuscular coordination. Although many substances theoretically have ergogenic properties, few are supported by robust scientific evidence as to their efficacy in either man or the horse. The evidence for and against various postulated nutritional ergogenic aids, including creatine, carnitine, oil supplementation, amino acids and β-hydroxy-β-methylbutyrate (HMB), with particular reference to the horse, is examined and discussed.