THE EFFECT OF N,N-DIMETHYLGLYCINE ON ATHLETIC PERFORMANCE AT ALTITUDEIN HORSES AND MULES

N,N-dimethylglycine (DMG) is widely used to delay fatigue by inhibitin g lactate production. DMG effects were examined in a paradigm of moder ate exercise intensity that was potentially oxygen-limited. Performanc e in seven horses and four mules was assessed using blood lactate conc entrations and heart rates. The experimental group was administered 2. 2 g of DMG twice per day for four days. The exercise tests consisted o f two exercise bouts, one starting at an elevation of 2635m and the ot her at 1960m. Work at the high altitude increased the total number of heart beats and recovery time in both horses and mules. There were no difference for peak heart rate (152+/-11 vs 141+/-2, p=0.32) average h eart rate, (99+/-2 vs 97+/-3, p=0.40) and blood lactates (0.62+/-0.05 vs 0.66+/-0.04 mM, p=0.78) between higher altitude and lower altitude tests, respectively. When data were pooled for species and altitude, D MG reduced blood lactates, (0.60+/-0.03 vs 0.74+/-0.06 mM, p=0.03).