Kinematics of blood lactate concentration during an incremental treadmill test in saddle horses

Summary The purpose of this study was to investigate the kinetics of blood lactate concentration in 5 saddle horses during an incremental test on an inclined treadmill (3%). In order to mimic field conditions, the exercise test consisted of five 3 min bouts at increasing speeds (7.5, 8.3, 9.2 and 10 m/s); each bout being followed by 1 min rest. Blood samples were taken prior to each step, every minute during each step and every 30 s during each rest period. At low intensities of exercise, stability of blood lactate concentration was sometimes observed during the first minutes of the bout, followed by an increase in the second part. At higher intensities, blood lactate concentration rose more quickly and no stability was observed. Lactate concentration in the blood sample taken at t3′30 during the rest period, often reached a higher value than in the preceeding bout. The VLa4 calculated from blood lactate concentrations obtained at t3′ and t3′30 were not significantly different (P>0.05); mean ± s.d. 9.8 ± 0.7 and 9.8 ± 0.6 m/s, respectively. By using the blood lactate concentrations obtained at t4', the VLa4 appeared higher (mean ± s.d. 10.1 ±0.7 m/s).