Incremental test until exhaustion

An exercise test was used to evaluate the performance variables. The test consisted of a progressive load until exhaustion, on a cycle ergometer (Ergoline 900; Bitz, Germany) equipped with a gas analyzer (Metamax. Cortex Biophysik. Gmbh. Germany) and a Polar pulsometer (Polar. Norway).

Depending on the degree of training, two different protocols were used. The effort protocol used for the HTG consisted of 1 min entirely at rest, 15 min of warm-up, ending with 5 min at 100 watts; then starting at 150 watts and increasing the intensity by 25 watts every 3 min until reaching the maximum power they could maintain. In the case of MTG and CG, it consisted of 1 min entirely at rest, 15 min of warm-up ending with 5 min at 40 watts; then starting at 50 watts and increasing the intensity by 25 watts every 3 min until reaching the maximum power they could maintain. All tests were carried out under similar atmospheric conditions (21–24 °C and 45–55% relative humidity and atmospheric pressure between 700 and 715 mmHg).

The choice of these protocols was based on previous studies in which a slight increase in intensity was recommended for each step [25] and an adequate duration of the test (until exhaustion) to obtain VO₂ max [26], as well as an adaptation based on the subject’s training level. Therefore, although starting with different loads, all the groups would face tests of similar duration and with the same increase in intensity [27]. The test was carried out on a cycle ergometer because of the greater accessibility for the collection of blood samples during the trial.

Training intensity and volume were reduced the two previous days applying a regenerative load to avoid fatigue in the test.