Physical, Hematological, and Biochemical Responses to Acute Intense Exercise in Polo Horses

The aim of this study was to evaluate the response of physical, hematological, and biochemical parameters after acute intense exercise in polo horses playing in an outdoor international competition. The game consisted of four periods (chukkas) and each period consisted a playing time of 7 minutes. Two matches were played everyday for a week. A total of 12 horses were examined. Each “high-goal” polo horse played one chukka a day for 4 days. Horses were clinically examined the day before the games started and then daily during the 4 days of their participation in the games. During these days, physical examination was performed and blood sample was collected at rest (T0), immediately (T1) after exercise, and after 30 minutes of exercise (T2). Blood samples were analyzed for total cell counts and for determination of creatine kinase, lactate dehydrogenase (LDH), aspartate aminotransferase, lactate, total proteins, calcium, magnesium, phosphorus , and cortisol. Data were evaluated using two-way analysis of variance. Exercise caused significant dehydration (P < .01), mucous membranes congestion, increased heart rate (P < .001), and capillary refill time (P < .001). It also caused increased value of the following parameters: hematocrit (P < .001), red blood cells (P < .001), hemoglobin (P < .001), white blood cells (P < .05), lymphocyte (P < .001), total proteins (P < .001), creatine kinase (P < .05), LDH (P < .01), lactate (P < .001), and cortisol (P < .01), and a decrease in the platelet count (P < .001), calcium (P < .01), phosphorus (P < .001), and magnesium (P < .001). All parameters returned within or near the reference range by 30 minutes postexercise. On the basis of these observations, data were considered indicative of a good response to an acute intense exercise. Moreover statistical results obtained were typical of a mixed aerobic/anaerobic metabolic pathway that is prevailing in this sport.