Avaliação ergoespirométrica de equinos em esteira e a campo

Abstract

The aim of this study was to compare ergoespirometric tests performed in the field and on the treadmill. Fifteen Brazilian Sport Horses were used, in training for Eventing, in a paired data with two treatments (treadmill and field tests) and 15 repetitions (horses). The incremental speed test on the treadmill consisted by walking for 3 minutes at 1.7 m/s, trotting for 3 minutes at 4 m/s, with 3.3% inclination, and gallops starting at 6 m/s with a 1 m/s increment of speed every 3 minutes until 9 m/s. The incremental speed test in the field was performed continuously and consisted by walking for 3 minutes at 1.7 m/s, trotting for 3 minutes at 4 m/s and gallops starting at 6 m/s with a 1 m/s increment of speed every 3 minutes until 8 m/s. Statistic differences were observed on the plasma lactate concentrations at 8 m/s, of 5.5±3.5 e 6.9±2.6 mmol/L (P=0.02957). No statistical differences were observed between treadmill and field tests on values of V200, of 8.82±1.19 e 8.79±1.37 m/s, respectively. Values of VL2 and VL4 on treadmill tests were 6.10±1.32 e 7.61±1.24 m/s. There was no significant difference in heart rate between tests. Respiratory rate varied between tests, with differences between tests on a treadmill and the field at times 1.7 and 6 m/s (P=0.0010 e P=0.0325). There was a significant difference in VT between tests (P=0.0121), and between treadmill and field tests on the 4.0; 6.0; 7.0 e 8.0 m/s (P=0.0017, P=0.0015, P=0.0022, P=0.0019) with interaction between the test and evaluated speeds. There were differences in the absolute values of VE between the test and between speeds 1.7; 4.0; 7.0 e 8.0 m/s (P=0.0022, P=0.0181, P=0.0085, P=0.0465). No differences were observed on the absolute or relative oxygen uptake, on the absolute or relative carbon dioxide production and on the respiratory quotient between treadmill and field tests. Values of plasma lactate, pH, bicarbonate, total carbon dioxide and base excess decreased with exercise tests. Ergospirometry performed on continuous incremental speed exercise test on the treadmill and in field was effective in measuring respiratory and ventilatory parameters and perfectly feasible. The variables HR, V200, VO2 and VCO2, observed in tests on a high-speed treadmill and in the field did not differ significantly between tests, demonstrating that the tests involved the same aerobic metabolic demand and are therefore comparable. Evaluation using blood gas analysis allowed observation of the acid-base balance during testing, indicating metabolic acidosis resulting from the exercise performed and the subsequent compensation.