Physiological responses of reining horses to interval training versus conventional training procedures

Abstract

Eight mature Quarter Horses were used in a cross-over hics. experiment to determine the efficacy of an interval training program versus a conventional training program to enhance fitness in the reining performance horse. The two training treatments were conducted in 31-d experimental periods which were each preceded by 28-d standardizing periods. In the conventional protocol, horses were ridden 5 days per week at an aerobic level of work on d 1 and 5. Day 2, 3 and 4 of each week included an additional intense maneuver workout for 20 min to stimulate anaerobic energy systems. The interval training program was conducted 6 days per week and was designed to implement the "overload'' principle by exercising the horses to the same physiologic endpoint approaching fatigue on d 2 and 5. On interval work days, 'ton-board'' heart rate monitors were used to record heart rates through a series of anaerobic maneuver repetitions with 1 min of recovery in between repetitions. When peak and recovery heart rates became elevated over previous repetitions, fatigue was declared and the workout ended. Exercise on d 1 and 4 followed the same protocol as that used for the conventionally trained horses, and on d 3 and 6, horses were ridden at a jog for 20 min. A standardized reining exercise test (RET) which included all the reining maneuvers (circling, spinning, stopping), was administered on d 0, 28 and 31 of each experimental period. The RET was designed to work the horses at an intensity past the anaerobic threshold. Heart rate (HR), respiratory rate (RR), rectal temperature (RT) and venous blood samples were taken prior to, during and through recovery from the RET. Both training protocols resulted in significantly lower [(1M0.05)] plasma lactate concentrations at stopping and post-exercise times on d 28 when compared to d 0. However it was only following interval training that this increase in aerobic capacity response was repeated on d 31. On d 31 of the conventional protocol, plasma lactate concentrations were significantly higher during circling and spinning, and from the last stop to 2 min recovery. exceeding pre-treatment values.