There has been little research to date on preventing muscle breakdown in sport horses. © Horsesports Photographic
People exercise to lose fat or build up muscle, but it can be an unfortunate consequence of hard training that muscle is lost. To counter this effect, people may take dietary supplements, legal or otherwise.
Professor René van den Hoven and his colleagues in the Institute of Animal Nutrition at the University of Veterinary Medicine, in Vienna, looked at what could legally be done to help train sport horses by preventing muscle loss.
They came up with a mixture of amino acids and proteins able to prevent muscle breakdown in horses following exercise.
Their findings are published in the current issue of the Journal of Animal Physiology and Animal Nutrition.
It is well known that hard training can lead to degradation of muscle protein, the researchers noted. A number of nutritional strategies have been developed to counter it, but, surprisingly, there has to date been little attention paid to the situation in sport horses.
Van den Hoven's team investigated standardbred trotters before and after intense exercise on a high-speed treadmill.
Because protein degradation within cells takes place by a number of different mechanisms, the researchers investigated potential markers for each of the pathways.
They also examined whether the activity of the pathways was affected if the animals received an amino acid/protein supplement - developed for human sportsmen and sportswomen - after exercise.
The results showed that one of the classic pathways for protein degradation, the so-called ubiquitination pathway, was dramatically activated four hours after the exercise period, at least as judged by the level of messenger RNA encoding ubiquitin.
This indicates strongly that the horses were breaking down protein in their muscles (by the ubiquitination pathway) as a result of heavy exercise.
Importantly, the increase could be significantly reduced by the amino acid/protein supplement. Changes to the other pathways studied were comparatively minor and little affected by the food supplement.
Van den Hoven is cautiously excited by the findings.
"It will be important to attempt to verify our results on larger sample sizes," he says, "but the initial indications are that the use of a protein/amino acid mixture can decrease protein degradation in trained horses and thus could have an advantageous effect on muscle mass."