Rating of Perceived Exertion (RPE)

Individuals can rate their perceptions of exertion while doing exercise. This rating should reflect how hard and strenuous the exercise feels to them. They should combine all sensations and feelings of physical stress, effort, and fatigue, and focus on the overall perception of their exertion rather than concerning themselves with any single factor, such as breathing rate or leg soreness. While exercising, they should look at the RPE scale (Figure 1), which ranges from 6 to 20, in which 6 denotes “rest” and 20 means “exhaustion,” and identify the number on the RPE scale that best describes their level of exertion. The RPE method can provide a good idea of the intensity level of activity. In turn, this information can be used to speed up or slow down movements, or if performing aerobic exercise, to reach the desired intensity range. If performing resistance exercise, RPE can be used to increase or decrease the weight an individual is lifting to obtain the preferred intensity. Individuals should make every effort to appraise their feelings of exertion as honestly as possible and be encouraged to rate their own feelings of effort and exertion rather than comparing themselves to others.

Exercise intensity is arguably the most critical component of the exercise prescription model. Failure to meet minimal threshold values may result in lack of a training effect, whereas a too-high intensity could lead to overtraining and, consequently, impact adherence to an exercise program. Excessive exercise intensity may also cause cardiovascular problems in those with risk factors for cardiovascular disease. The RPE method can be particularly advantageous if heartrate-monitoring methods may compromise accurate exercise-intensity prescription. For example, RPE is the preferred method to assess exercise intensity among those individuals who take medications that affect heart rate, such as beta-blockers. Additionally, the RPE method may be superior to a heart rate method that uses an estimate of maximal heart rate to establish target exercise intensity. In fact, it has been demonstrated that, in approximately 30% of the population, there are large errors in excess of +/-10% of the actual target exercise intensity when maximal heart rate is predicted from an equation (i.e., 220-age). The error is exacerbated further in older individuals, where there is greater variability in maximal heart rate. Furthermore, the consequence of errors in target exercise intensity are magnified in older adults due to greater likelihood of cardiovascular disease. In summary, the RPE method can be used to set an accurate exercise intensity for individuals on heart-rate-lowering medications and when it is not feasible to measure maximal heart rate.

Cardiorespiratory fitness is arguably the most important goal of an exercise program for older adults, as low cardiorespiratory fitness may contribute to premature mortality in middle-aged and older adults. The literature suggests a 15% reduction in mortality for a 10% improvement in cardiorespiratory fitness. Moreover, decreased cardiorespiratory fitness contributes to a reduction in physiological functional capacity and, eventually, can result in loss of independence. To minimize complications and promote long-term compliance, exercise intensity for inactive older adults should start low and progress according to client preference and tolerance. Additionally, many adults have clinically diagnosed conditions or likely have underlying chronic diseases; thus, a conservative approach to increasing intensity may be required. Moderate-intensity aerobic exercise consists of a moderate level of effort relative to the aerobic fitness level of an individual. On a 0 to 10-point scale, where resting is 0 and an all-out/cannot-continue effort is 10, moderate-intensity activity is a 5 or 6 and produces noticeable increases in heart rate and breathing rate. On the same 0 to 10-point scale, vigorous-intensity activity is a 7 or 8 and elicits substantial increases in heart rate and breathing rate. It should be noted that given the considerable heterogeneity of aerobic fitness levels in older adults, for some older adults a moderate-intensity walk (RPE of 5 or 6) is a slow walk, and for others it is a brisk walk.

Aging is associated with a reduction in muscle mass, which in turn contributes to decreased muscle strength and a decline in functional capacity. Undeterred, the process can ultimately result in balance impairments, mobility problems, and lack of independence for the older adult. Furthermore, decreased muscle mass plays a role in the development of glucose intolerance and Type 2 diabetes. Maximal exercise testing in older adults is usually not recommended. As such, the RPE scale is useful to establish exercise intensity in this group. Overall, for older adults, it is recommended that eight to 10 exercises be performed on two or more nonconsecutive days per week using the major muscle groups. Each resistance exercise should be performed with a resistance that permits 10–15 repetitions per exercise. Level of effort for muscle-strengthening activities should be moderate-to-high. On a 0 to 10-point scale, where resting equals 0 and maximal effort equals 10, moderate-intensity effort equals 5 or 6, and high-intensity effort equals 7 or 8.

Lance C. Dalleck, PhD