The speed was then increased by 0.5 kmh-1 every 30 s until volitional exhaustion. The highest velocity completed was considered as the peak treadmill speed associated to the last complete stage (Speak). Expired gases were continuously measured (Cortex Biophysik, Germany) and the VO2max (mL·kg·min-1) recorded was the mean of the values reached during the last 20 s before exhaustion. Heart rate (HR) was continuously recorded at 5 s intervals (RS800, Polar Electro Oy, Finland