PERCEPTION OF EFFORT IN SELECTED SAMPLES OF OLYMPIC ATHLETES AND SOLDIERS

Summary Whether one is concerned with the physical performance of the high-level athlete, soldier, industrial worker, or middle-aged jogger, the important consideration is frequently not what the individual is actually doing , but rather what he or she thinks they are doing. In this respect the study of perceived exertion has a great deal to offer in our understanding of human physical performance. Indeed, it has recently been demonstrated that perception of effort during sub-maximal exercise predicts maximal work capacity as well as more traditional “physiological” measures such as heart rate (Morgan and Borg, 1976). Also, the use of perceived exertion ratings possesses adequate validity, objectivity, and reliability and, in addition, the procedure is quite parsomonious. Furthermore, with exception of the situation where the test S is neurotic, anxious, or depressed, most S s (90%) can accurately rate the intensity of work cost in a psychophysical sense (Morgan, 1973). Therefore, it would seem logical that ratings of perceived exertion would represent a useful application in the study of physical fitness from both a cross sectional and longitudinal standpoint. However, the studies reviewed in the present paper suggest that the interface between physical fitness (aerobic power) and perception of effort is far more complex than one might suspect. On the other hand, the lack of substantial differences in the rating of absolute work by S s differing in fitness may reflect the lack of veridical perception in the less fit S . The earlier papers by Linderholm (1967), Docktor and Sharkey (1971) and Ekblom and Goldbarg (1971) all suggest that perception of effort during standard or absolute ergometry decreases with physical training. The S s in the study by Docktor and Sharkey (1971) actually had similar ratings of perceived exertion before (RPE = 11.4) and following (RPE = 10.6) five weeks of training. However, the length of time required to achieve the criterion heart rate (PWC150) had actually increased, and therefore, the post-training rating was made at a significantly higher absolute workload. Hence, their findings imply that a decrease in rating of perceived exertion took place for given sub-maximal absolute loads. In Linderholm's (1967) study Swedish military conscripts were studied before and after four months of training, and both heart rate and perceived exertion decreased approximately 20% for the same sub-maximal workload. Ekblom and Goldbarg (1971) evaluated nineteen male S s before and after an eight week physical training program. The mean shifts in RPE units at 25%, 50%, and 75% of maximal aerobic power were 2.1, 1.4, and 1.8 respectively, and these changes were consonant with those observed in the training study reported as experiment 3. That is, Patton, et al ., (1975) observed a decrement of 1.2 RPE units following six months of training. While decrements of 1–2 RPE units may not seem to be substantial, it is possible that such reductions in perception of effort are quite meaningful. First of all, a decrease in perceived exertion of 1.5 units may not be appreciable for a given point within a sub-maximal effort, but if such a decrement were extended over a marathon, for example, the consequences would be obvious. Second, rather than viewing RPE changes in absolute terms (i.e., 1–2 units), it might be more appropriate to talk in percent decrement. The decrement of 1.2 RPE units observed by Patton, et al . (1975) represents a decrease of 11%. At any rate, it has been reported by a number of investigators that chronic physical activity tends to decrease the rating of perceived exertion by 10–20% (1–2 RPE units) in most training studies. Unfortunately, most of the experimental studies carried out on a longitudinal basis have not employed control groups for comparative purposes. Also, there has been virtually no attempt made in these studies to control for bias due to demand characteristics implicit in such protocols. Furthermore, it has been demonstrated that hypnotic perturbation of perceived exertion at an acute level is capable of provoking perceptual changes equal to those seen in chronic training studies lasting one to six months. Therefore, one must conclude that convincing evidence has not been presented to support the view that physical training reduces the perception of effort for absolute work performed at sub-maximal levels. It is recommended that this matter be further investigated at both the cross sectional and longitudinal levels for selected sub-maximal workloads. It would also seem useful at this time to incorporate the concept of “veridical perception” into efforts concerned with prediction of human physical performance.