The effects of short intensive exercise on plasma free amino acids in standardbred trotters.

This study investigates how short, intense exercise impacts plasma amino acid concentrations in trotters, using blood samples from 36 standardbred trotters. The research also assesses the repeatability of the plasma amino acids concentration in two different instances of sampling, showing that exercise can significantly influence plasma amino acid concentrations.

Methodology

• The study involved 36 standardbred trotters, who participated in intense exercise covering a distance of 2000m.
• Plasma amino acid concentrations were measured in their blood both before and after the exercise.
• The exercise intensity was gauged from the lactate levels in the horses post-exercise.
• Based on their post-exercise lactate concentration, the horses were divided into two groups. The cut-off for these groups was a lactate concentration of 15 mmol/l.
• Sequences of sampling were repeated after 35 days in 20 of the original 36 horses.

Findings

• The concentrations of several plasma amino acids like alanine, aspartate, glutamate, isoleucine, leucine, lysine, and taurine increased after the exercise.
• On the other hand, exercise led to a decrease in the plasma concentrations of other amino acids such as arginine, asparagine, citrulline, glutamine, glycine, histidine, methionine, serine, tryptophan, and 3-methylhistidine.
• Concentrations of certain amino acids – ornithine, threonine, tyrosine, phenylalanine, and valine – remained consistent regardless of the exercise.
• A higher intensity of exercise was found to significantly increase the concentration of taurine but decreased tryptophan concentrations.
• The sampling day was found to have a significant effect on the absolute pre- and post-exercise amino acid concentrations.

Implications

• The changes in plasma amino acid concentrations in trotters brought about by exercise could reflect the shifts within the free amino acid compartments.
• There were also signs of muscle catabolism, as indicated by the rise in some plasma amino acid concentrations and the decrease in others after exercise.
• The study suggests that the supply of amino acids in sport horses could be crucial for maintaining muscle health and enhancing post-exercise recovery in competitive horses.