LIPID STATUS IN RACEHORSES FOLLOWING PHYSICAL ACTIVITY OF VARIOUS INTENSITY AND DURATION

The aim of this research was to determine the effects of physical activity on the lipid status in racehorses in a gallop race and a forty-kilometre endurance ride. Two groups of healthy 3-5-year-old full-blooded racehorses were assessed. The first one ran a 2 400-m gallop race, which is considered a short-lasting, intense physical activity; lipid status was assessed prior to, and 48 and 72 h after the race. The second group ran a forty-kilometre endurance ride, which is a long-lasting moderate physical activity; the lipid status was assessed immediately before, soon after and 48, 72, 96, 120 and 144 h after finishing the race. In intense physical activity the parameters of lipid status (total cholesterol, HDL cholesterol, LDL cholesterol, free cholesterol and triglycerides) remained stable at all times assessed in comparison with basal concentrations (p>0.05). Following the long-lasting moderate physical activity a slight, although statistically insignificant (p>0.05), increase in the concentrations of total cholesterol, HDL cholesterol, free cholesterol and LDL cholesterol was noticed immediately after the endurance ride in comparison to the values before the ride. By contrast, the concentration of LDL cholesterol increased immediately after the gallop race, which was followed by its significant decrease (p<0.05) 96, 120 and 144 h after the ride in comparison to the values both before and immediately after the ride. Unlike in the gallop race, immediately after the 40-km endurance ride there was a plummet in triglyceride concentration (p<0.01), but was followed by its statistically significant increase (p<0.05 and p<0.01) at all sampling times in comparison to the value on finishing the ride. In horses which ran the gallop race there was a high positive correlation between the concentrations of total cholesterol, HDL cholesterol and triglycerides before, 72 and 96 h after the race (r = 0.9278, p<0.001). In those which ran the endurance ride a high positive correlation between the concentrations of total cholesterol and HDL cholesterol was noticed on finishing the ride (r=0.7395 p<0.01), as well as at all sampling times which followed. In addition, there was a positive correlation between the concentrations of HDL cholesterol and LDL cholesterol 72 h (r=0.6843, p<0.01) after the ride. Aerobic exercise decreases the risk of cardiovascular diseases, partly because-it is accompanied by the moderate increase in serum concentration of HDL cholesterol, decrease in total cholesterol, LDL cholesterol and triglycerides, which all result in the improvement in lipid profile in horses which completed the endurance ride.