Perceptrial and Motor Skills, 1979, 48, 992-994. @ Perceptual and Motor Skills 1979
PERCEIVED EXERTION OF PROFESSIONAL HOCKEY PLAYERS J. ROSENTSWIEG, D. WILLIAMS, C. SANDBURG, K. KOLTEN, L. ENGLER, AND G. NORMAN Texas Woman's University1 Summary.-18 professional hockey players were tested on the treadmill with a modified Balke procedure and also for maximum isokinetic strength with the Cybex I1 instrument. Immediately after each test the subject completed the Borg Scale of Perceived Exertion. The treadmill effort was perceived as being "somewhat hard w o r k while the maximum strength effort was considered "very light." This conflicts with previous literature. It may be that professional hockey players adapt to physical stress and do not respond perceptually to such stimuli in a typical manner.
Perceived exertion or the subjective cost of work has been studied by a number of sport psychologists during the past decade. The attempt to validate the perception of effort with psychophysical techniques demands acceptance of scaling methodology which uses a ratio scale. Stevens (1957) has stated that perceptions could be perceived as falling within the boundaries of ratio scaling. Direct physiological validation of most perceptions has not been made; therefore indirect measurement is necessary. Borg ( 1962) proposed a scale of perceived exertion to examine the psychophysical properties of work. Users of this scale tend to believe that the scale may be considered valid and reliable (Borg & Noble, 1974). The Rating of Perceived Exertion was based upon the heart rate which is known to have a linear relationship with work until great stress is encountered at which time the relationship becomes exponential. The scale was designed to reflect one-tenth the heart rate, thus a rating of 6 is approximately equivalent to a hearc rate of 60, and a rating of 20 would demand exertion similar to that of a working heart rate of 200. Variations do exist but the concept has been consistently upheld.
METHOD Eighteen professional hockey players were tested on a treadmill using a modified Balke procedure where the percent grade started at 0 and increased 1% per min. with the speed constant at 3.3 mph. A Quinton cardiotachometer was used to determine heart rate. Expired gases were collected for 1 min. at heart rate of 180 in a Tissot gasometer and values determined by calibrated Beckman E-2 and LB-1 gas analyzers. Subjects were naive to the treadmill. The maximum isokinetic strength of the knee extensors was obtained after the treadmill test. Familiarity with the Cybex I1 instrument was provided and then the strength measure was taken with the speed of extension controlled at 10 rpm. The subjects sat on the accessory bench with the arms folded across the 'College of Health, Physical Education, and Recreation, Denton, TX 76204.
PERCEIVED EXERTION OF HOCKEY PLAYERS
993
chest and the thigh strapped in place. Immediately after each test a rating of perceived exertion was completed.
RESULTSA N D DISCUSSION Table 1 describes the hockey players and their performance. These hockey players, playing in a minor league but anticipating they would become highly paid professional athletes in the major leagues, are relatively taller and heavier than the general population. The oxygen consumption at heart rate 180 indicates a particularly aerobically fit group. The measure of strength of the knee extension was exceptional also. Clarke ( 1966) states thac the mean strength for young college males in an isometric measure taken in an approximately similar body position was 112.94 Ib. The 160 Ib. of strength exerted by the hockey players suggests great, if not maximum voluntary effort. TABLE 1 -
M Age ( ~ 1 . ) Weight (kg.) Height (cm)
Range or u
22.93 20-29 84.06 6.65 70.10 2.08
VO, (ml/kg) Treadmill RPE Knee Extension Strength (Ib.) Strength RPE
M
Range or u
56.42 13.06
9.94 11-17
160.67 31-41 9.13 8-12
The perceived exertion of the treadmill test by the hockey players was that it was "somewhat hard." A rating of perceived exertion of 13 falls in the middle of the scale. The Balke protocol theoretically demanded more than "very hard w o r k (heart rate 180). A variation of approximately one-third the total scale value is too grear to be explained as an effect of training, especially on an unfamiliar task. It seems logical to assume that professional hockey players experience highly vigorous, very stressful physical activity with sufficient frequency to lower the relative perceptual value of a given effort. Also, the requirement of playing when injured in a very dangerous sport might explain why this particular group felt thac very hard work was only moderately stressful. The strength data are more unusual to define. Personal observations and discussions with competitive weightlifters using isokinetic techniques has indicated that a maximum effort, full-extension movement at 10 rpm can exhaust a person. Untrained young men assign a rating of perceived exertion of 13 for the knee-extension movement at 10 rpm. These unpublished data of Rosentswieg2 from untrained men might be interpreted as indicating that they
9. Rosentswieg. Perceived exertion of isokinetic strength movements. datiz, 1978)
(Unpublished
J. ROSENTSWEIG,
ET AL.
were not sufficiently motivated or did not know how to give a maximum effort as well as did trained weightlifters. The hockey players' mean rating of perceived exertion ( 9 ) was even lower than that of the untrained men, yet the professional athletes were very familiar with weight training at maximum load. It may be that a two-factor theory of perceived exertion implying central and local mechanisms (Ekblom & Goldbarg, 1971), with the local factors assuming greater importance in activities of small muscle groups or anaerobic work provides a rationale. The work involved in the knee extension may be over too quickly for the difficulty to be appropriately perceived as exertion by these professional athletes. Certainly the cardiorespiratory factor would be limited. Another reasonable answer might be that no one cared enough to attempt a "real" maximum effort in the task because they were aware of the fatiguing consequences and they knew that they were going to participate in additional physical tests. A third possibility would coincide with one suggested for the treadmill effort, that professional players are accustomed to pain and that any effort not eliciting pain is perceived as only moderate. Perceived exertion, a subjective concept, must be interpreted with great care as it not only appears to be task specific but population specific, and is based upon more than just physical fitness elements. Professional hockey players probably adapt to greater physical stress than do most individuals and therefore probably do not subjectively view exertion in the same manner as do others less accustomed to pain and maximal efforts. REFERENCES Physical performance and perceived exertion. Lund: Gleerups, 1962. BORG,G. A. V. BORG.G . A. V., & N O B L ~B. , J. Perceived exertion. In J. H. Wilmore (Ed.), Exercise and sport sciences reuietus. Vol. 2. New York: Academic Press, 1974. Pp. 131153. CLARKE, H. H. M t ~ s c u b r~ t r e n g t hand endurance in man. Englewwd Cliffs: PrenticeHall, 1966. EKBLOM, B.. & GOLDBARG, A. N . The influence of physical training and other factors on the subjective rating of perceived training. Acta Physiologica Scandinauica, 1971, 82, 399-406. STEVENS, S. S. O n the psychophysical law. Psychological Review, 1957, 64, 153-181. Accepted May 11, 1979.
PERCEIVED EXERTION OF PROFESSIONAL HOCKEY PLAYERS J. ROSENTSWIEG, D. WILLIAMS, C. SANDBURG, K. KOLTEN, L. ENGLER, AND G. NORMAN Texas Woman's University1 Summary.-18 professional hockey players were tested on the treadmill with a modified Balke procedure and also for maximum isokinetic strength with the Cybex I1 instrument. Immediately after each test the subject completed the Borg Scale of Perceived Exertion. The treadmill effort was perceived as being "somewhat hard w o r k while the maximum strength effort was considered "very light." This conflicts with previous literature. It may be that professional hockey players adapt to physical stress and do not respond perceptually to such stimuli in a typical manner.
Perceived exertion or the subjective cost of work has been studied by a number of sport psychologists during the past decade. The attempt to validate the perception of effort with psychophysical techniques demands acceptance of scaling methodology which uses a ratio scale. Stevens (1957) has stated that perceptions could be perceived as falling within the boundaries of ratio scaling. Direct physiological validation of most perceptions has not been made; therefore indirect measurement is necessary. Borg ( 1962) proposed a scale of perceived exertion to examine the psychophysical properties of work. Users of this scale tend to believe that the scale may be considered valid and reliable (Borg & Noble, 1974). The Rating of Perceived Exertion was based upon the heart rate which is known to have a linear relationship with work until great stress is encountered at which time the relationship becomes exponential. The scale was designed to reflect one-tenth the heart rate, thus a rating of 6 is approximately equivalent to a hearc rate of 60, and a rating of 20 would demand exertion similar to that of a working heart rate of 200. Variations do exist but the concept has been consistently upheld.
METHOD Eighteen professional hockey players were tested on a treadmill using a modified Balke procedure where the percent grade started at 0 and increased 1% per min. with the speed constant at 3.3 mph. A Quinton cardiotachometer was used to determine heart rate. Expired gases were collected for 1 min. at heart rate of 180 in a Tissot gasometer and values determined by calibrated Beckman E-2 and LB-1 gas analyzers. Subjects were naive to the treadmill. The maximum isokinetic strength of the knee extensors was obtained after the treadmill test. Familiarity with the Cybex I1 instrument was provided and then the strength measure was taken with the speed of extension controlled at 10 rpm. The subjects sat on the accessory bench with the arms folded across the 'College of Health, Physical Education, and Recreation, Denton, TX 76204.
PERCEIVED EXERTION OF HOCKEY PLAYERS
993
chest and the thigh strapped in place. Immediately after each test a rating of perceived exertion was completed.
RESULTSA N D DISCUSSION Table 1 describes the hockey players and their performance. These hockey players, playing in a minor league but anticipating they would become highly paid professional athletes in the major leagues, are relatively taller and heavier than the general population. The oxygen consumption at heart rate 180 indicates a particularly aerobically fit group. The measure of strength of the knee extension was exceptional also. Clarke ( 1966) states thac the mean strength for young college males in an isometric measure taken in an approximately similar body position was 112.94 Ib. The 160 Ib. of strength exerted by the hockey players suggests great, if not maximum voluntary effort. TABLE 1 -
M Age ( ~ 1 . ) Weight (kg.) Height (cm)
Range or u
22.93 20-29 84.06 6.65 70.10 2.08
VO, (ml/kg) Treadmill RPE Knee Extension Strength (Ib.) Strength RPE
M
Range or u
56.42 13.06
9.94 11-17
160.67 31-41 9.13 8-12
The perceived exertion of the treadmill test by the hockey players was that it was "somewhat hard." A rating of perceived exertion of 13 falls in the middle of the scale. The Balke protocol theoretically demanded more than "very hard w o r k (heart rate 180). A variation of approximately one-third the total scale value is too grear to be explained as an effect of training, especially on an unfamiliar task. It seems logical to assume that professional hockey players experience highly vigorous, very stressful physical activity with sufficient frequency to lower the relative perceptual value of a given effort. Also, the requirement of playing when injured in a very dangerous sport might explain why this particular group felt thac very hard work was only moderately stressful. The strength data are more unusual to define. Personal observations and discussions with competitive weightlifters using isokinetic techniques has indicated that a maximum effort, full-extension movement at 10 rpm can exhaust a person. Untrained young men assign a rating of perceived exertion of 13 for the knee-extension movement at 10 rpm. These unpublished data of Rosentswieg2 from untrained men might be interpreted as indicating that they
9. Rosentswieg. Perceived exertion of isokinetic strength movements. datiz, 1978)
(Unpublished
J. ROSENTSWEIG,
ET AL.
were not sufficiently motivated or did not know how to give a maximum effort as well as did trained weightlifters. The hockey players' mean rating of perceived exertion ( 9 ) was even lower than that of the untrained men, yet the professional athletes were very familiar with weight training at maximum load. It may be that a two-factor theory of perceived exertion implying central and local mechanisms (Ekblom & Goldbarg, 1971), with the local factors assuming greater importance in activities of small muscle groups or anaerobic work provides a rationale. The work involved in the knee extension may be over too quickly for the difficulty to be appropriately perceived as exertion by these professional athletes. Certainly the cardiorespiratory factor would be limited. Another reasonable answer might be that no one cared enough to attempt a "real" maximum effort in the task because they were aware of the fatiguing consequences and they knew that they were going to participate in additional physical tests. A third possibility would coincide with one suggested for the treadmill effort, that professional players are accustomed to pain and that any effort not eliciting pain is perceived as only moderate. Perceived exertion, a subjective concept, must be interpreted with great care as it not only appears to be task specific but population specific, and is based upon more than just physical fitness elements. Professional hockey players probably adapt to greater physical stress than do most individuals and therefore probably do not subjectively view exertion in the same manner as do others less accustomed to pain and maximal efforts. REFERENCES Physical performance and perceived exertion. Lund: Gleerups, 1962. BORG,G. A. V. BORG.G . A. V., & N O B L ~B. , J. Perceived exertion. In J. H. Wilmore (Ed.), Exercise and sport sciences reuietus. Vol. 2. New York: Academic Press, 1974. Pp. 131153. CLARKE, H. H. M t ~ s c u b r~ t r e n g t hand endurance in man. Englewwd Cliffs: PrenticeHall, 1966. EKBLOM, B.. & GOLDBARG, A. N . The influence of physical training and other factors on the subjective rating of perceived training. Acta Physiologica Scandinauica, 1971, 82, 399-406. STEVENS, S. S. O n the psychophysical law. Psychological Review, 1957, 64, 153-181. Accepted May 11, 1979.
