This study aimed to verify the effect of “marcha” training on clinical, hematological and biochemical variables in Mangalarga Marchador horses. Twelve Margalarga Marchador horses were used, six females and six males. Each animal was submitted to gait training lasting 40 minutes on hard ground. These animals were already conditioned to the proposed training. The animals were assessed before exercise (M0) and immediately after its ending (M1). Was realized physical examination and collected blood samples by jugular venipuncture to obtain blood, plasma and serum for hematological and biochemistry profiles. The “marcha” training caused changes in values of all clinical and laboratory variables evaluated. At the physical examination showed increases in cardiac and respiratory rates, as well as in rectal temperature. An increase was observed in erythrocyte, hemoglobin, hematocrit and leukocyte values. Electrolytes such as sodium, potassium, chloride, magnesium and ionic calcium showed a decrease in their plasma concentration. An increase in strong ion difference (SID) was observed due to the decrease of the chloride concentration causing a discreet metabolic alkalosis. There was an increase in the plasma concentrations of Lactate, glucose, CPK, total proteins and fibrinogen. As conclusion, the “marcha” causes small changes in the clinical, hematological and biochemical profiles in horses previously conditioned to this exercise.