Objective:

To compare the effects of a resistance training protocol (ER) with a traditional protocol (ET) on blood lactate concentration and CK.

Materials and methods:

Two training protocols were applied for 6 months divided into three stages. Effort tests were performed before beginning the training protocols and at the end of each stage. In each test, samples of venous blood were taken at rest, during exercise and in recovery to measure lactate (L), and at the beginning and at the end to measure creatine kinase (CK) and infer metabolic and muscular adaptations. The difference in baseline lactate medians was calculated using Mann Whitney U and the mean difference in the percentage of clearance between the groups was compared through the Students' T test.

Results:

A significant difference in the percentage of lactate clearance between ER and ET was found. There was also a significant increase in intra-group CK values, before and after the tests, but remaining within the reference ranges.

Discussion:

ER increased the ability to metabolize post-exercise lactate in foals with resistance training, although there was no difference between the maximum production of L between the ER group and ET. The behavior of CK within the reference ranges indicates that there was no muscle damage in the foals of both groups of foals.