A comparative study of aerobic capacity and fitness in three different horse breeds (Andalusian, Arabian and Anglo-Arabian).

Aerobic capacity and fitness was studied in three different horse breeds (Andalusian, Arabian and Anglo-Arabian) using a four-level exercise test of gradually increasing intensity (15, 20, 25 and 30 km/h). The lactate concentration at the first three exercise levels was significantly lower for Arabian and Anglo-Arabian horses relative to Andalusian horses, but similar for the three breeds at the last level. Arabian and Anglo-Arabian horses reached a higher rate than Andalusian horses at plasma lactate concentration of 2 mmol/l (VLA2) and 4 mmol/l (VLA4). Andalusian horses exhibited a significantly lower heart rate at rest than the other two breeds, but the differences virtually disappeared at 15 km/h. At 20 km/h, Andalusian horses reached a higher heart rate than Arabian and Anglo-Arabian horses; at 25 km/h, however, their heart rate only exceeded that of Anglo-Arabian horses. Finally, no significant differences between breeds were observed at 30 km/h. No differences between breeds as regards heart rate were found if this was expressed as a function of lactate plasma concentrations of 2 mmol/l (HRLA2) and 4 mmol/l (HRLA4). At a heart rate of 150 (VHR150) and 200 beta/min (VHR200), Andalusian horses achieved the lowest speeds.