Effects of creatine supplementation in the Thoroughbred horse



The present study was undertaken to examine the absorption of creatine (Cr) by the horse and, if so, whether this results in an uptake of Cr into muscle. The timecourse for the appearance of a single dose of creatine monohydrate (Cr.H2O), given by nasogastric intubation, in plasma was investigated in 4 horses. Individual resting plasma [Cr] ranged from 8 μmol/1 to 103 μmol/1. Mean post intubation plasma concentrations showed a modest increase reaching a peak after 6 h. At various times post intubation the change from rest was statistically significant. The effect of 13 days feeding of 0.15g/kg body mass/day of Cr.H2O on muscle [TCr] was studied in 4 horses. Supplementation had no effect upon muscle [TCr] (pre- vs. post supplementation: 104 ± 4 vs. 98 ± 14 mmol/kg dry muscle). There was no change either in the resting muscle [ATP] (pre- vs. post supplementation: 21.2 ± 1.0 vs. 20.2 ± 1.9 mmol/kg dry muscle) or the [TCr]/[ATP] ratio.