The gas exchange responses were measured breath‐by‐breath using a stationary gas analyzer (Quark CPET, Cosmed), coupled with a heart rate transmitter (Wireless HR 138 Monitor, Cosmed). The gas analyzer was calibrated before each test using an ambient air sample and a high‐precision gas mixture (3.98% CO2, 16.02% O2, and balanced N2; White Martins Gases Industriais Ltda), whereas the pneumotachograph was calibrated through a 3 L syringe (Hans Rudolf), in accordance with the manufacturer's instructions. For analysis of cardiorespiratory responses, the raw data were smoothed using five points moving average and were interpolated every 1 s using the software OriginPro 8.0.
Furthermore, to determine the blood lactate concentration ([La−]), blood samples from the earlobe (25 μl) were taken in the 3rd and 5th min after the graded exercise test and at rest, 3rd, 5th, and 7th min after constant‐load supramaximal effort, transferred to Eppendorf tubes containing 50 μl of 1% sodium fluoride, and kept frozen at −20°C until the assay. The samples were analyzed in duplicate using a biochemical analyzer YSI 2900 (Yellow Spring Instruments, EUA) with a measurement error ranging from ±2%. We used the Borg scale (6–20) to assess the rating of perceived exertion (RPE) on every effort.
Furthermore, to determine the blood lactate concentration ([La−]), blood samples from the earlobe (25 μl) were taken in the 3rd and 5th min after the graded exercise test and at rest, 3rd, 5th, and 7th min after constant‐load supramaximal effort, transferred to Eppendorf tubes containing 50 μl of 1% sodium fluoride, and kept frozen at −20°C until the assay. The samples were analyzed in duplicate using a biochemical analyzer YSI 2900 (Yellow Spring Instruments, EUA) with a measurement error ranging from ±2%. We used the Borg scale (6–20) to assess the rating of perceived exertion (RPE) on every effort.