Comparison of physiological responses to exercise in horses on a conditioning regimen versus inactive horses receiving a yucca and fenugreek dietary supplement

Yucca and fenugreek are purported to reduce inflammation and improve metabolic response to exercise. Therefore, we evaluated the effects of a dietary supplement (DigestaWell NRG) in unconditioned horses completing an exercise challenge test. In this study, 10 unfit horses were assigned to receive exercise (EXC; n = 5) or the dietary supplement (SUP; n = 5). Horses assigned to EXC were ridden daily at a walk, trot, and canter. Horses assigned to SUP were ridden once per week at a walk and slow trot, but received no other exercise. Horses underwent a 14-min standardized exercise test (5 min walk, 5 min trot, 4 min canter) prior to (Period1) and after a 4-wk treatment period (Period2). Heart rate, respiration rate, blood lactate concentrations, and thermal images of six muscle groups were obtained prior to, immediately after, and 2 hr post-test. Data were analyzed using repeated measures ANOVA. During Period1, similar (P > 0.05) post-exercise increases in heart rate, respiration rate, blood lactate, and thermal images were observed regardless of treatment group. During Period2, SUP horses had lower (P < 0.001) lactate concentrations than EXC horses at 2 hr post exercise, and it is possible that these lower concentrations are responsible for lower peripheral temperatures. Infrequently exercised horses may benefit from yucca and fenugreek supplementation due to the observed effect of these herbs to reduce post-exercise lactate concentrations and peripheral temperatures.