Ratings of perceived exertion in adults with chronically physical challenges

The purposes of this study were to investigate: the relationship between ratings perceived exertion (RPE) and percentage of maximal oxygen uptake (%VO2max) during submaximal exercise; the influence of daily physical activities on RPE; and the influence of aerobic fitness on RPE.

The participants were thirty-eight adults with chronically physical challenges. Submaximal exercise testing was conducted to estimate VO2max. The participants themselves declared their perceived exertion just before the end of the exercise testing by indicating the Borg's 6-20 RPE scale. Measurement of continuous heart rates was employed for measurement of the intensity of daily physical activities. The relationship between %VO2max and RPE was analyzed.

There was a significant correlation between %VO2max and RPE only in the active men who did daily aerobic physical activities with intensity of 30%HRR and more (N.=9, r=0.74, P=0.02). In the good fitness groups of both women and men, the actual %VO2max in 11 out of 12 participants was lower than the reference value of %VO2max of the RPE while the opposite trend was found in poor aerobic fitness group.

Our results recommend that RPE should be used together with objective physiological variables such as HR for assessment of exercise intensity in people with chronically physical challenges, especially who are low in aerobic fitness or who are inactive.