Effects of the sudden climbing to an average height over the subjective perception of effort in different levels of exercise
Sixteen healthy males, were submitted to a maximum incremental test in conditions of normoxia (N) and of moderate acute altitude (Alt) in two different days. Rating of perceived exertion (RPE), respiratory data, heart rate and lactate were measured during the test. The values at maximum work and at the lactate thresold (LT) were compared between both conditions. Meaningful differences between the work, RPE, VO2 (l.min-1), Ve (l.min-1) y Lac (mMol.l-1) were not observed at the related intensities. However, though the HR registered in N at the LT did not show differences with the HR obtained in Alt, there was an important reduction of the HR at the maximum work reached in the condition of hypoxia (188 ± 9 vs 182 ± 7 ppm, p<.001). The sudden ascent to a moderate altitude does not alter the RPE in the LT, neither at the maximum work. Under these conditions the HR seems not to be so good index of the work intensity as the RPE.
KEY WORDS: RPE, altitude, hypoxia, lactate threshold.