Heart rate, hematological and serum biochemical responses to show jumping

Changes in heart rate (HR), plasma lactate (LA) and some other blood parameters were studied in 16 healthy show jumping horses participating in the Belgian Junior Championship. Venous blond was collected from each horse before and immediately after competing and was analysed for packed cell volume (PCV), LA, plasma cortisol, blood glucose (GLU), total plasma protein bicarbonate ions and serum levels of lactate dehydrogenase, creatine kinase, aspartate aminotransferase and gamma glutamyl transferase (GGT). A HR recorder placed under the saddle continuously recorded HR from the warm-up tu 5 min after the course in 10 horses. Show jumping induced a significant increase in all parameters, except GLU, which decreased significantly, and GGT which remained unchanged. Resting values of LA and HR were 0.43±0.05 mmol I-1 and 44.7±2.9 beau min-1 respectively. Post-exercise LA reached a mean value of 8.7±0.5 mmol I-1, while HR rose to a peak of 189.2±3.5 beau min-1 during Ihe course. The results of the present study demonstrated that, although the speed and duration of such an exercise are low, show jumping represents severe exertion which requires some anaerobic metabolism.