Perception of Effort During Resistance Exercise

This study used ratings of perceived exertion for the overall body (RPE-O) to examine the perception of effort during resistance exercise. Eight men completed 2 trials in a counter- balanced design: a single bout of resistance exercises at 70% 1-RM, and the same exercises at 50% of 1-RM. Blood lactate concentrations [bLa] were measured before each trial, immediately after each exercise, and at 30 and 60 min post for each trial. Heart rate and systolic BP were also recorded at these same time periods. RPE-O were obtained immediately after each exercise using the Borg 10-point category-ratio scale. Significant elevations in [bLa], HR, and SBP occurred in response to both bouts of exercise. The increase in exercise intensity from 50 to 70% of 1-RM corresponded with a significant increase in [bLa] and RPE-O, but not HR or SBP. It appears that the perception of effort increases along with increases in % 1-RM lifted. Accumulation of [bLa] may mediate this. These findings support the use of the Borg scale for monitoring resistance exercise intensity.