Effects of Aerobic Training on Systolic, Diastolic and Mean Blood Pressure in Arabian Horses

Exercise causes several physiological changes resulting from autonomic and hemodynamic adaptations, but there are few reports about the behaviour of blood pressure ( BP ) during physical activity in horses, as well as the effect of training on BP . Methods 9 untrained Arabian horses underwent two treadmill evaluations (before and after 90 days of aerobic training at 60% HRmax ) at 6% incline with incremental speed increases every 3 minutes (commencing at 2.5 m/s and reaching 12.5 m/s). The facial artery was cannulated with a 20 G catheter and systolic blood pressure ( SBP ), mean ( MAP ) and diastolic ( DBP ) blood pressures were recorded with a multiparameter monitor ( GE Dash 3000 model). Data were evaluated by two‐way ANOVA for repeated measures and Bonferroni multiple comparison (P<0.05). Results During initial evaluation SBP increased in a gradual and uniform manner as speed increased, reaching a maximum of 208 mmHg at a speed of 10 m/s. After training, SBP behaved similarly during treadmill evaluation, however values were lower until 10 m/s (P<0.001), and the maximum value of SBP obtained was 218 mmHg at 12.5 m/s. DPB was not significantly different (P = 0.124). MAP emulated the behaviour of SBP (P = 0.012). Conclusions A decrease in SBP and MAP during identical treadmill evaluations before and after 90 days of aerobic exercise (60% HR max) indicated that training decreased cardiac effort required for the maintenance of physical activity. Ethical Animal Research procedures were approved by the University of S ão P aulo. Sources of funding:  none declared. Competing interests:  none.