The effects of atropine and practolol on the perception of exertion during treadmill exercise

Ct, Davies; Aj, Sargeant

doi:10.1080/00140137908924688

Cited by 41 publications

(18 citation statements)

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“…The non-responsiveness of heart rate to ozone exposure is consistent with previous investigations (Folinsbee et al 1978) and suggests that this parameter is not critical as a sensory cue for perception of effort. Several investigations have provided support for this latter suggestion (Davies and Sargeant 1979, Ekblom and Goldbarg 1971, Pandolf et al 1972.…”

Section: Discussionmentioning

confidence: 74%

Perception of effort and respiratory sensitivity during exposure to ozone

1981

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The purpose of this study was to examine the effectsof exposure to the air pollutant ozone during exercise on perception of effort and to evaluate perceptual sensitivity to respiratory responses during this exposure. Fourteen male subjects were exposed to ozone concentrations of 0'00, 0'30, and 050p.p.m. during both resting and bicycle ergometer exercise treatments. Ratings of perceived exertion were obtained periodically during the 40 min exercise period. Perceptual exponents were determined from magnitude estimation and production of lung volumes obtained before, at the approximate midpoint, and at the end of the 2 hour exposure period. Significant (p <0'01) decrements in FYC, FEY" and MEF 25-75 resulting from ozone exposure were greater immediately following an exercise bout. Perception of effort based on sensory input from above the waist (central) increased significantly (p < 0'05) with increasing ozone concentrations. The increase in central perceived exertion appeared sooner in the exercise period and was of a greater magnitude during 0·50 p.p.m. ozone in comparison with overall perceived exertion and ratings localized to the exercising muscles. Perceptual exponents derived from magnitude estimates during the exercise treatment were significantly (p<0'05) higher than for the room air condition. It was concluded that perceptual responses to exercise and respiratory stimuli during ozone exposure reflected the decrements in pulmonary function observed with exposure to ozone.

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Section: Discussionmentioning

confidence: 74%

Perception of effort and respiratory sensitivity during exposure to ozone

1981

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“…Pacing strategy is thought to be a function of metabolic and biochemical afferents to the CNS that are 'hardwired' through past experiences (St Clair Gibson et al 2001;Ulmer 1996) and/or modified by afferent feedback signals from factors such as substrate availability, heart rate and lactic acidosis (Mihevic 1981;Rauch et al 2005;Ulmer 1996). Thus, when these factors are manipulated by pharmaceutical (Davies and Sargeant 1979) or hypnotherapy interventions (Morgan 1973), self-selected work rate may be affected.…”

Section: Introductionmentioning

confidence: 97%

Effect of altered pre-exercise carbohydrate availability on selection and perception of effort during prolonged cycling

et al. 2006

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This study assessed the effect of altered carbohydrate (CHO) availability on self-selected work rate during prolonged time-trial cycling. Eight endurance-trained men undertook two experimental cycling time-trials after glycogen-depleting exercise and 2 days of: (a) high (9.3 +/- 0 g CHO kg(-1) day(-1)) (HC) and (b) low CHO intakes (0.6 +/- 0.1 g CHO kg(-1) day(-1)) (LC), via a double-blinded crossover design. All feedback regarding performance was removed during both exercise trials. Self-selected external power output was not different during the first 2 h of exercise between experimental conditions (P > 0.05), despite reported sensations of increased tiredness before and during exercise, significantly reduced whole body CHO oxidation (P < 0.05), plasma lactate concentrations (P < 0.05) and earlier onset of fatigue during exercise in LC versus HC. Perceived exertion was not different throughout exercise between conditions (P > 0.05). Mean power output declined significantly in LC versus HC (P < 0.05) after approximately 2 h of exercise, and was associated with significant reductions in cadence, heart rate and plasma glucose concentration (P < 0.05). These results demonstrate that when compared with time-trial cycling performed after a HC diet, reduced CHO availability does not initially alter self-selected work rate in endurance athletes who are deceived of their CHO status prior to exercise. This finding suggests that reduced work rate during exercise following lowered CHO intake may, in part, be a consequence of the subject's awareness of dietary CHO restriction rather than solely a physiologically mediated action. Further research is required to distinguish the influence of circulating glucose and peripheral glycogen availability on pacing strategy during prolonged exercise.

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“…For these individuals, due to the blunting of normal heart rate response by b blockers, VO 2 max cannot be predicted from the present CST procedure. However, because it is known that at intensities ,65%VO 2 max, the relation between RPE and work rate is unaltered by b blockade, [9][10][11][12] this may still allow the CST to show an improvement in fitness from reductions in heart and RPE for a given CST stage.…”

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confidence: 99%

Reliability and validity of measures taken during the Chester step test to predict aerobic power and to prescribe aerobic exercise

et al. 2004

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Objectives: To evaluate the reliability and validity of measures taken during the Chester step test (CST) used to predict VO 2 max and prescribe subsequent exercise. Methods: The CST was performed twice on separate days by 7 males and 6 females aged 22.4 (SD 4.6) years. Heart rate (HR), ratings of perceived exertion (RPE), and oxygen uptake (VO 2 ) were measured at each stage of the CST. Results: RPE, HR, and actual VO 2 were the same at each stage for both trials but each of these measures was significantly different between CST stages (p,0.0005). Intertrial bias ¡95% limits of agreement (95% LoA) of HR reached acceptable limits at CST stage IV (22¡10 beats/min) and for RPE at stages III (0.2¡1.4) and IV (0.5¡1.9). Age estimated HRmax significantly overestimated actual HRmax of 5 beats/min (p = 0.016) and the 95% LoA showed that this error could range from an underestimation of 17 beats/min to an overestimation of 7 beats/min. Estimated versus actual VO 2 at each CST stage during both trials showed errors ranging between 11% and 19%. Trial 1 underestimated actual VO 2 max by 2.8 ml/kg/min (p = 0.006) and trial 2 by 1.6 ml/kg/min (not significant). The intertrial agreement in predicted VO 2 max was relatively narrow with a bias ¡95% LoA of 20.8¡3.7 ml/kg/min. The RPE and %HRmax (actual) correlation improved with a second trial. At all CST stages in trial 2 RPE:%HRmax coefficients were significant with the highest correlations at CST stages III (r = 0.78) and IV (r = 0.84). Conclusion: CST VO 2 max prediction validity is questioned but the CST is reliable on a test-retest basis. VO 2 max prediction error is due more to VO 2 estimation error at each CST stage compared with error in age estimated HRmax. The HR/RPE relation at .50% VO 2 max reliably represents the recommended intensity for developing cardiorespiratory fitness, but only when a practice trial of the CST is first performed.T he Chester step test (CST) was originally developed by Kevin Sykes at University College Chester to assess aerobic fitness by predicting maximal aerobic power (VO 2 max) in fire brigades in Britain, Europe, USA, and Asia, and more recently for work with airport firefighters, the ambulance service, health authorities, and corporate institutions.1 It also features in commercial health and fitness assessment packages and most noticeably one in particular (Fitech Pty Ltd, Australia; www.fitech.com.au). The CST is one of many tests designed to provide a safe and practical means of assessing aerobic fitness under submaximal conditions. Examples of other similar tests include the Astrand-Ryhming nomogram cycle ergometer protocol, 2 the American College of Sports Medicine protocols for cycle ergometry and treadmill, 3 and the Canadian standardised step test of fitness. 4 The limited equipment needed (step, heart rate monitor, portable cassette or compact disk player, and perceived exertion scale) makes the CST very portable and requirements for space are minimal, which is advantageous compared with similar protocols using treadmills, shutt...

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The effects of atropine and practolol on the perception of exertion during treadmill exercise

Cited by 41 publications

References 10 publications

Perception of effort and respiratory sensitivity during exposure to ozone

Perception of effort and respiratory sensitivity during exposure to ozone

Effect of altered pre-exercise carbohydrate availability on selection and perception of effort during prolonged cycling

Reliability and validity of measures taken during the Chester step test to predict aerobic power and to prescribe aerobic exercise

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