Bruce J. Noble

A category-ratio perceived exertion scale: relationship to blood and muscle lactates and heart rate.

The purpose of this investigation was to study the relationship between perceptual ratings from Borgs new category-ratio scale and some physiological variables during exercise. To accomplish this, scale ratings were related to blood and muscle lactate accumulation and heart rates during a progressive, maximal exercise test on the cycle ergometer. Ten physically active males were utilized as subjects; lactate data were recorded on only 7 of the 10 subjects. Three ratings of perceived exertion were made at each stage of the exercise test: leg effort (LE), cardiorespiratory effort (CE), and leg pain (LP). All ratings showed a positively accelerating increase with exercise intensity as did both blood and muscle lactate, while heart rate increased linearly. The exponents of the power functions describing the perceptual variation ranged from 1.63-1.67 compared to 2.2 for blood lactate and 2.7 for muscle lactate. Polynomial analysis revealed a similar quadratic trend for both perceptual and blood lactate data; however, muscle lactate demonstrated a cubic trend. No significant differences were found between CE and LE at 100, 200, and 300 W (P greater than 0.05). Subjects with the highest percentage of slow-twitch muscle fibers (mean ST%=51.14) rated LE and CE significantly lower ( mean of all power outputs, 0-300 W) than those with the lowest ST% (mean=34.52). It is concluded that the ratings from the category-ratio scale correspond very well with glycogenolytic metabolism leading to lactate accumulation during exercise.

Clinical applications of perceived exertion.

The purpose of this paper is to review those studies related to the clinical applications of perceived exertion. The Borg Scale has been used most widely to evaluate the subjective response of patients during graded exercise tests. More recently, ratings of perceived exertion (RPE) have been shown to be an accurate predictor of aerobic capacity. Appraisal of angina pectoris during exercise is discussed relative to its interaction with effort perceptions. Two groups of investigators have recently studied the validity of using stress-test perceptions to control exercise intensity during training. Caution is suggested when perceptual prescriptions are based upon estimation techniques in exercise tests but require production techniques by patients in exercise programs. One investigation was reviewed to illustrate the use of perceptual information in solving occupational problems: three lifting techniques were compared relative to perceptual acceptability, the recommended squat technique being the least acceptable. A variety of sport applications were discussed: perception of pace, sex differences in perception of effort, perceptual recovery from exercise, and the new Borg Category-Ratio Scale in the measurement of anaerobic stress and several recommendations were made for future study of clinical applications of perceived exertion.

Maximal exercise during hypobaric hypoxia (447 Torr) in moderate-altitude natives.

Six low-altitude natives (LAN) (373 m or less, aged 19-25 yr) and eight moderate-altitude natives (MAN) (1830-2200 m, aged 19-23 yr) were studied at both their residence (home) altitude (740 Torr and 587 Torr, respectively) and in a hypobaric chamber at a simulated altitude of 4270 m (447 Torr). Following a 2-d adaptation period, subjects performed an incremented test on the cycle ergometer until voluntary exhaustion. Significantly (P less than 0.05) greater differences in percent change of maximum exercise variables (total exercise time, exercise intensity, VO2, VCO2, VE/VO2 and HR) were noted in the LAN group than in the MAN group, going from their residence altitude to 447 Torr. The decrement in VO2max was 15% in the MAN group compared to 34% in the LAN group. The anaerobic threshold (% VO2max), estimated from VE BTPS measurements, was similar in both groups at residence altitude and at 447 Torr. In the morning prior to exercise testing at 447 Torr, LAN subjects reported greater (P less than 0.001) symptoms of acute mountain sickness (AMS) than MAN subjects. Our results indicate that, with respect to maximum exercise performance, moderate-altitude natives are at an advantage during early adaptation to hypobaric hypoxia.

Response of plasma proenkephalin Peptide F to exercise

Plasma proenkephalin Peptide F immunoreactivity was measured in the plasma of endurance trained and untrained males at various exercise intensities. Significantly different levels were found between the two groups at rest and at 54% maximum oxygen consumption (VO2 max). Maximum levels were at 5 min of recovery for the untrained group and at 54% VO2 max and at recovery 5 min for the trained group. These data suggest an adaptation in the trained group fro the release of this peptide and further suggest it may play a role in recovery since the highest levels are following the termination of the exercise period.

Effects of hypnosis on plasma proenkephalin peptide F and perceptual and cardiovascular responses during submaximal exercise

SummaryLittle information is available concerning the influence of subconscious mechanisms on neuroendocrine function, more specifically, proenkephalin peptide F release. Ten men [5 middle distance runners (21.6 (SD 0.54 years) and 5 untrained men (24.0 (SD 4.3 years)] consented to be volunteers in this investigation. Submaximal exercise intensities of 25% and 50& of peak oxygen consumption ({ie573-1}) (8 min stages) were used for both the control and hypnosis treatments. A traditional hypnotic induction was used, with the suggestion of two higher intensities of exercise stress (50% and 75% peak {ie573-2}) previously experienced in familiarization and testing by each subject. Each minute oxygen consumption was measured using open circuit spirometry, heart rate via an ECG, and ratings of perceived exertion (RPE) using the Borg scale. Plasma peptide F immunoreactivity (ir) [preproenkephalin-(107–140)] in blood sampled from an indwelling cannula was measured by radioimmunoassay at 7–8 min of each stage of the exercise test. Expected significant increases were observed for all cardiorespiratory and perceptual variables over the increasing exercise intensities and there were no significant differences between trained and untrained groups for peptide F it response patterns. Hypnosis did not significantly affect peptide F it concentrations (P > 0.05) and did not significantly alter exercise heart rate, RPE or minute ventilation (P > 0.05). However, hypnosis did significantly increase oxygen consumption during exercise (P = 0.0095) but not of the magnitude needed for the metabolic demands of the higher exercise intensities. Thus, traditional hypnosis was unable to make functionally significant changes in the cardiorespiratory variables. Training did not alter responses to exercise under hypnosis. The results of this study indicate that when using traditional hypnosis and a suggestion of harder exercise in highly selected groups, it may not be possible functionally to stress adrenal medullary secretion of proenkephalin fragments, RPE or cardiorespiratory variables.

Perceived exertion during hypobaric hypoxia in low- and moderate-altitude natives.

Ratings of perceived exertion (RPE) were examined in six low- (LAN) and eight moderate- (MAN) altitude natives during exercise at their residence (home) altitude (366 m and 2,200 m, respectively) and 1-4 wk later following 2-d decompression to 4,270 m (447 mm Hg). Cardiorespiratory, plasma lactate, and differentiated RPE measures were obtained at exercise intensities representing 35, 55, 75, 85, and 100% VO2peak. In general, cardiorespiratory and plasma lactate values were similar in LAN and MAN at their residence altitudes and during hypobaric hypoxia. However, the decrease in VCO2 was greater (P < 0.05) in LAN than MAN. At their residence altitudes, both LAN and MAN reported local RPE values that were greater (P < 0.05) than central ratings at the moderate to high exercise intensities. At 447 mm Hg, central and local RPE were similar in LAN. However, there was a significant correlation between acute mountain sickness (AMS) symptoms and central RPE (r = 0.875) across the five exercise intensities in LAN. The differences between the central and local RPE noted in MAN during their residence testing also persisted at 447 mm Hg. Thus, differentiated ratings of perceived exertion were similar in MAN at their residence altitude and at 4,270 m, but not in LAN subjects. Several factors, including AMS, may have contributed to this group difference in the RPE response.

Validity of perceptions during recovery from maximal exercise in men and women.

The Borg Scale, widely used to measure perceptions of exercise, has not been validated for use during recovery. Heart rate was used as the validity criterion. 11 untrained men and 10 untrained women were run to exhaustion on a treadmill. Heart rate and recovery ratings were obtained at:15, :45, 1:15, 1:45, 2:30, 3:30 and 4:30 min. following exercise. No significant differences were observed between sexes for both heart rate and recovery ratings. Trend analysis showed recovery ratings to be linear between :45 and 4:30 while heart rate is best described by two linear trends with a break point at 2:30. Percent recovery was significantly faster for recovery ratings at :45, 1:15, 1:45 and 4:30. Heart rate and recovery ratings were not significantly correlated at any time point. A perceptual scale should be designed which more closely approximates metabolic response during recovery.

Acute Exposure of College Basketball Players to Moderate Altitude: Selected Physiological Responses.

Abstract Ten basketball players and two coaches ([Vdot]O2 max = 51.08 ml/kg · min) were studied at their place of residence in Chadron, Nebraska (1,000 m, PB = 661 mm Hg), and 6 days later in Laramie, Wyoming (2,200 m, PB = 584 mm Hg). Subjects rode the bicycle ergometer through several submaximal workloads until voluntary exhaustion. Laramie tests took place within 8 hours after arrival and at the same time of day as the Chadron tests. Submaximal heart rate, oxygen consumption, pulmonary ventilation, carbon dioxide production, respiratory quotient, and perceived exertion were not significantly altered by the altitude change; however, ventilatory equivalent was significantly higher in Laramie (p < .05). The hypoxia-induced decrease in the anaerobic threshold ( workload = 906 kpm/min at both sites) which was hypothesized was not observed. Likewise, resting hematocrit and hemoglobin were not affected by the 1,200 m altitude increment (44.88 vs. 44.53% and 15.39 vs. 15.01 gm%, respectively). Maximum aerobic ...