The effects of a training program on V200, HRpeak and worked distance were evaluated in two horse breeds with distinct aptitudes. Five Arabian (GA) and five Crioulo (GC’) adult horses were subjected to incremental exercise tests on a 6% slope, which consisted of 5 minutes at 1.8m s-1, 3 minutes at 4m s-1, 2 minutes at 6m s-1, then 1 minute steps at 8m s-1, 9m s-1, 10m s-1 and 11m s-1 or until the horse could not keep up the speed even being encouraged. V200 was achieved through linear regression analyses of heart rate vs. speed. Individual maximum oxygen uptake (VO2máx) was determined to establish speed during 9 weeks of training, being 35% of the VO2máx for 5 weeks, 50% for 2 weeks, and 100% for two additional weeks. Horses were exercised once a day, for 5 days a week, on a 6% slope. Mean V200 before training (M0) was 7.4±0.5m s-1 and 7.4±1.,2m s-1, for GA and GC, respectively, and after training (M1) was 7.8±0.8m s-1 and 7.0±0.7m s-1, for GA and GC, respectively. Mean HRpeak at M0 was 221.6±9.0 and 207.4±7.3 for GA and GC, respectively, and 226.0±8.4 and 215.0±7.7 at M1,for GA and GC respectively. Worked distance at M0 was 3391.0±252.0 and 2446.0±96.3 for GA e GC respectively, and at M1 was 3850.8±462.2 and 2698.6±335.8 for GA and GC respectively. No significant differences were observed between groups (P=0.4643) or moments (P=1.0) for V200. To HRpeak. there was statistical difference only between groups (P=0.0064). For the index of the distance traveled there was statistical difference between groups (P=0.0002) and moments (P=0.0092). Training probably conditioned horses to anticipate exercise when taken to the treadmill, therefore increasing heart rate and being an influence on V200 values. V200 was considered ineffective to assess differences in athletic performance between breeds and to evaluate the effect of treadmill training. Therefore it is necessary to associate other performance indicators as the distance to ensure appropriate interpretation of training effect programs on equine performance.
cardiovascular system; exercise physiology; heart rate; horse
