The purposes of this study were to assess if women 60 to 75 years of age perceived a series of exercise intensities differently from selected intensities in that series and to determine if a particular intensity was perceived more reliably. Twenty-four women (65 +/- 3.8 yr) completed a walking VO2max treadmill test. Subjects were either assigned to a variable, randomly ordered exercise protocol (GP1) or to one of three constant exercise protocols (Gps2-4). Each subject performed relative exercise intensities of 30, 50, and 70% of peak VO2 for three 5 min work bouts over 3 test days. Differences in RPE (p < 0.05) were found between each intensity and between the same intensities from both protocols. Women in GP1 rated exercise higher than women who exercised at a constant exercise intensity (p < 0.05). Intraclass correlation coefficients indicated that the exercise intensity of 50% of maximum was more reliable regardless of the protocol (Gp1: R = 0.97, Gp3: r = 0.94). When the RPE-HR correlation coefficients were transformed into a log scale, neither protocol had a stronger association (p > 0.05) between RPE-HR. It was concluded that older women should be given a range of exercise intensities that include the 50% relative exercise intensity as a perceptual marker in order to reach a reliable rate of exertion.