Table 3 Data from 10 young two-year-old Thoroughbred horses undergoing introductory track-based training. Post-exercise whole blood hematocrit (HCt, %), plasma ammonia (NH3, μmol/L) and blood lactate (mmol/L) between the early-training (week 4) HSET and late-training (week 12) HSET. Values presented as mean ± SD