Biomedical subjects

R G Eston

Publications and source records attributed to R G Eston.

At least 19 recordsLinked to original sources

PubMed2005

Prediction of DXA-determined whole body fat from skinfolds: importance of including skinfolds from the thigh and calf in young, healthy men and women.

OBJECTIVE: To investigate the relationship of percent body fat (%fat), assessed by dual energy-X-ray absorptiometry (DXA) or a four-compartment model, with upper body and lower limb skinfolds. DESIGN: Cross-sectional design involving forward stepwise and hierarchical multiple regression analyses to assess the relationship of %fat with skinfolds and a combination of four commonly used upper body skinfolds (biceps, triceps, subscapular and iliac crest) with the calf and thigh skinfolds. SETTING: University research laboratory. SUBJECTS: In all, 31 females, mean age 20.9 (+/-2.0) y, and 21 males, mean age 22.3 (+/-5.5) y volunteered for this study, which was approved by the Ethics Committee of the School of Sport, Health and Exercise Sciences, University of Wales, Bangor. MEASUREMENTS: %fat from DXA in both groups, and %fat from a four-compartment (water, bone mineral mass, fat and residual) model (%fat4C) in females only. Skinfolds were measured at the abdomen, iliac crest, biceps, triceps, subscapular, calf and thigh. RESULTS: All skinfolds were positively associated with DXA estimates of %fat (P < 0.01). In males and females, the thigh skinfold had the highest correlation with %fat. This was also observed when %fat4C was used as the criterion in females. Stepwise multiple regression analysis using %fatDXA as the criterion selected the thigh (R(2) = 0.82), calf (R(2) change 0.04) and iliac crest (R(2) change = 0.03) for females, and the thigh (R(2) = 0.79), iliac crest (R(2) change = 0.11) and abdomen (R(2) change = 0.03) for males (all P < 0.01). When %fat4C was used as the criterion in the females, only the thigh was selected as a significant predictor (R(2) = 0.76). Independent prediction factors were created from the sum of biceps, triceps, subscapular and iliac crest (sigma4skf) and from the sum of the thigh and calf (sigmathigh + calf). These factors were then entered into a hierarchical multiple linear regression analysis to predict percent fat. Order of entry was varied to allow the assessment of unique variance accounted for by each predictor. The sum of the thigh and calf explained more variance in %fatDXA than that explained by the sigma4skf alone, irrespective of the order of entry in both males and females. This was also observed when %fat4C was used as the criterion in the females. CONCLUSIONS: The results of this study confirm that lower body skinfolds are highly related to percent body fat in fit and healthy young men and women, and uphold current recommendations by the British Olympic Association to include the thigh skinfold with sigma4skf. Conventional use of the sigma4skf to estimate percent body fat is significantly enhanced by the inclusion of the thigh and calf skinfolds, either independently or in combination. In this group of males and females, the sum of the thigh and calf skinfolds accounted for the most variance in percent fat.

Absorptiometry, Photon↗

PubMed2004

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

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 (-2+/-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 -0.8+/-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.

Adult↗

PubMed2001

Statistical analyses in the physiology of exercise and kinanthropometry.

Research into the physiology of exercise and kinanthropometry is intended to improve our understanding of how the body responds and adapts to exercise. If such studies are to be meaningful, they have to be well designed and analysed. Advances in personal computing have made available statistical analyses that were previously the preserve of elaborate mainframe systems and have increased opportunities for investigation. However, the ease with which analyses can be performed can mask underlying philosophical and epistemological shortcomings. The aim of this review is to examine the use of four techniques that are especially relevant to physiological studies: (1) bivariate correlation and linear and non-linear regression, (2) multiple regression, (3) repeated-measures analysis of variance and (4) multi-level modelling. The importance of adhering to underlying statistical assumptions is emphasized and ways to accommodate violations of these assumptions are identified.

Adaptation, Physiological↗

PubMed2001

Effect of stride length manipulation on symptoms of exercise-induced muscle damage and the repeated bout effect.

This study assessed the effects of stride length on symptoms of exercise-induced muscle damage after downhill running and whether the extent of the symptoms sustained in a repeated bout of downhill running are influenced by stride length manipulation in the first bout. Eighteen males aged 21.1 +/- 0.6 years (mean +/- s) were allocated to one of three groups for bout one: preferred stride frequency, overstride and understride. Bout two was performed 2 weeks later at the participants' preferred stride frequency. Maximal isometric force and perceived muscle soreness were assessed pre-test and 30 min, 24, 48 and 72 h post-exercise for each downhill run. Three-factor analyses of variance with repeated measures on time and bout were used for analysis. Results revealed a three-way interaction for soreness (F8,60 = 3.56, P < 0.05) and relative isometric strength (F5.0,37.8 = 3.2, P < 0.05). Post-hoc analyses revealed that, after bout one, the overstride group perceived most soreness and the understride group retained most strength. After the second bout, the overstride and preferred stride frequency groups perceived less soreness than the preferred stride frequency group in bout one. Strength retention was greater after bout two for all groups. In conclusion, strength retention after a repeated bout appears to be independent of the damage experienced in the initial bout of downhill running. However, understriding may provide least protection against soreness in a subsequent bout.

Adaptation, Physiological↗

PubMed2001

Electromyographic analysis of repeated bouts of eccentric exercise.

The repeated bout effect refers to the protective effect provided by a single bout of eccentric exercise against muscle damage from a similar subsequent bout. The aim of this study was to determine if the repeated bout was associated with an increase in motor unit activation relative to force production, an increased recruitment of slow-twitch motor units or increased motor unit synchronization. Surface electromyographic (EMG) signals were recorded from the hamstring muscles during two bouts of submaximal isokinetic (2.6 rad x s(-1)) eccentric (11 men, 9 women) or concentric (6 men, 4 women) contractions separated by 2 weeks. The EMG per unit torque and median frequency were analysed. The initial bout of eccentric exercise resulted in strength loss, pain and muscle tenderness, while the repeated eccentric bout resulted in a slight increase in strength, no pain and no muscle tenderness (bout x time effects, P < 0.05). Strength, pain and tenderness were unaffected by either bout of concentric exercise. The EMG per unit torque and median frequency were not different between the initial and repeated bouts of eccentric exercise. The EMG per unit torque and median frequency increased during both bouts of eccentric exercise (P < 0.01) but did not change during either concentric bout. In conclusion, there was no evidence that the repeated bout effect was due to a neural adaptation.

Adult↗

PubMed2001

Characteristics of isometric and dynamic strength loss following eccentric exercise-induced muscle damage.

Angle-specific isometric strength and angular velocity-specific concentric strength of the knee extensors were studied in eight subjects (5 males and 3 females) following a bout of muscular damaging exercise. One hundred maximal voluntary eccentric contractions of the knee extensors were performed in the prone position through a range of motion from 40 degrees to 140 degrees (0 degrees = full extension) at 1.57 rads(-1). Isometric peak torque was measured whilst seated at 10 degrees and 80 degrees knee flexion, corresponding to short and optimal muscle length, respectively. Isokinetic concentric peak torque was measured at 0.52 and 3.14 rad x s(-1). Plasma creatine kinase (CK) activity was also measured from a fingertip blood sample. These measures were taken before, immediately after and on days 1, 2, 4, and 7 following the eccentric exercise. The eccentric exercise protocol resuited in a greater relative loss of strength (P< 0.05) at short muscle length (76.3 +/- 2.5% of pre-exercise values) compared to optimal length (82.1 +/- 2.7%). There were no differences in the relative strength loss between isometric strength at optimal length and isokinetic concentric strength at 0.52 and 3.14 rad x s(-1). CK activity was significantly elevated above baseline at days 4 (P < 0.01) and 7 (P < 0.01). The greater relative strength loss at short muscle length appeared to persist throughout the seven-day testing period and provides indirect evidence of a shift in the angle-torque relationship towards longer muscle lengths. The results lend partial support to the popping sarcomere hypothesis of muscle damage, but could also be explained by an impairment of activation at short muscle lengths.

Adult↗

PubMed2000

Effect of stride length on symptoms of exercise-induced muscle damage during a repeated bout of downhill running.

The purpose of this study was to assess the effects of changes in stride length on the symptoms of exercise-induced muscle damage (EIMD) during a repeated bout of downhill running in a group of 18 men and women. Muscle tenderness, plasma creatine kinase activity (CK) and maximal voluntary isometric force were measured before and after two downhill runs, with each run separated by 5 weeks. The first downhill run was at the preferred stride frequency (PSF). Participants were then randomly allocated to one of three sex-balanced groups with equal numbers of men and women: overstride (-8% PSF), understride (+8% PSF) and normal stride frequency for the second downhill run. Stride length had no effect (P>0.05) on muscle tenderness, CK or isometric peak force. Increases in muscle tenderness (P<0.001) and CK were lower (P<0.05) following the second downhill run, although there was no difference in the pattern and extent of the strength decrement between the two runs. There were also no differences (P>0.05) in muscle tenderness, CK or the relative strength loss between the men and the women. Results suggest that the symptoms of EIMD are unaffected by gender and small alterations to the normal stride pattern during constant velocity downhill running. The observation that muscle tenderness and CK were reduced following a repeated bout of similar eccentric exercise is consistent with the phenomenon known as the 'repeated bout effect' of muscle damage.

Adult↗

PubMed2000

Electromyographic analysis of exercise resulting in symptoms of muscle damage.

Surface electromyographic (EMG) signals were recorded from the hamstring muscles during six sets of submaximal isokinetic (2.6 rad x s(-1)) eccentric (11 men, 9 women) or concentric (6 men, 4 women) contractions. The EMG per unit torque increased during eccentric (P < 0.01) but not during concentric exercise. Similarly, the median frequency increased during eccentric (P < 0.01) but not during concentric exercise. The EMG per unit torque was lower for submaximal eccentric than maximum isometric contractions (P < 0.001), and lower for submaximal concentric than maximum isometric contractions (P < 0.01). The EMG per unit torque was lower for eccentric than concentric contractions (P < 0.05). The median frequency was higher for submaximal eccentric than maximum isometric contractions (P < 0.001); it was similar, however, between submaximal concentric and maximum isometric contractions (P = 0.07). Eccentric exercise resulted in significant isometric strength loss (P < 0.01), pain (P < 0.01) and muscle tenderness (P < 0.05). The greatest strength loss was seen 1 day after eccentric exercise, while the most severe pain and muscle tenderness occurred 2 days after eccentric exercise. A lower EMG per unit torque is consistent with the selective recruitment of a small number of motor units during eccentric exercise. A higher median frequency during eccentric contractions may be explained by selective recruitment of fast-twitch motor units. The present results are consistent with the theory that muscle damage results from excessive stress on a small number of active fibres during eccentric contractions.

Adult↗

PubMed2000

Stages in the development of a research project: putting the idea together.

We have considered some of the most important factors involved in designing a viable study that will adequately address the research question. Although we do not profess to be experts in all aspects of the above, we have learned through experience that attention to many of the above points will help to avoid frustration during the experimental process and when the study is presented for external review and subsequent presentation and publication. Good luck in your research.

Double-Blind Method↗

PubMed2000

Ratings of perceived exertion in braille: validity and reliability in production mode.

OBJECTIVES: (a) To assess the validity and reliability of producing and reproducing a given exercise intensity during cycle ergometry using a braille version of Borg's standard 6-20 rating of perceived exertion (RPE) scale, and (b) to determine whether the exercise responses of blind participants, at a given produced RPE, were similar to those reported in recognised guidelines for sighted subjects. METHODS: Ten healthy registered blind volunteer participants (four women, six men; mean (SD) age 23.2 (9.0) years) performed an initial graded exercise cycle test to determine maximal heart rate (HRMAx) and maximal oxygen uptake (VO2MAX). Three trials of three exercise bouts at RPEs 9, 11, and 13 were then performed in random order on three separate days of the same week, with expired air and heart rate measured continuously. Each exercise bout was followed by 10 minutes of rest. The validity of the scale as a means of producing different exercise intensities was assessed using a two factor (RPE x trial) repeated measures analysis of variance. Intertrial reliability was assessed using intraclass correlation coefficients (ICC) and the bias +/-95% limits of agreement (95%LoA) procedure. RESULTS: Participants reported no difficulty in using the braille RPE scale. When asked to produce exercise intensities equating to RPE 9, 11, and 13, they elicited mean %VO2MAX values of 47%, 53%, and 63% respectively. Analysis of variance showed no significant differences in either %HRMAx or %VO2MAX between trials at each of the three RPEs, but there was a significant difference (p<0.001) in both %HRMAx and %VO2MAX between the three RPE levels. All pairwise comparisons of the three different RPEs were significantly different (p<0.016). The ICC between the second and third trial for %HRMAx was significant (p <0.05) for all three RPEs. Similarly for %VO2MAX, the ICC was significant for RPE 9 and 11 but not 13. The 95%LoA decreased for both %HRMAx and %VO2MAX with each successive trial. CONCLUSIONS: Blind participants were successful in using a braille RPE scale to differentiate exercise intensity on a cycle ergometer. In every trial at RPE 13, all participants achieved %HRMAX and %VO2MAX levels, which fell within the recommendedrange for developing cardiorespiratory fitness. Using %HRMAx as a judge of intertrial reliability, the participants were able to repeat similar exercise intensities after two trials at each of the three RPEs (9, 11,13). The same was true for RPE 9 and 11, when %VO2MAX was used as a judge, but further trials were required to achieve similar reliability at RPE 13. A braille RPE scale can be used by healthy blind people during cycle ergometry, with similar effect to the visual analogue scale recommended for use in healthy sighted people.

Adult↗

PubMed1999

Reliability of ratings of perceived exertion during progressive treadmill exercise.

OBJECTIVE: To assess the test-retest reliability (repeatability) of Borg's 6-20 rating of perceived exertion (RPE) scale using a more appropriate statistical technique than has been employed in previous investigations. The RPE scale is used widely in exercise science and sports medicine to monitor and/or prescribe levels of exercise intensity. The "95% limits of agreement" technique has recently been advocated as a better means of assessing within-subject (trial to trial) agreement than traditional indicators such as Pearson and intraclass correlation coefficients. METHODS: Sixteen male athletes (mean (SD) age 23.6 (5.1) years) completed two identical multistage (incremental) treadmill running protocols over a period of two to five days. RPEs were requested and recorded during the final 15 seconds of each three minute stage. All subjects successfully completed at least four stages in each trial, allowing the reliability of RPE responses to be examined at each stage. RESULTS: The 95% limits of agreement (bias +/- 1.96 x SDdiff) were found to widen as exercise intensity increased: 0.88 (2.02) RPE units (stage 1), 0.25 (2.53) RPE units (stage 2), -0.13 (2.86) RPE units (stage 3), and -0.13 (2.94) RPE units (stage 4). Pearson correlations (0.81, 0.72, 0.65, and 0.60) and intraclass correlations (0.82, 0.80, 0.77, and 0.75) decreased as exercise intensity increased. CONCLUSIONS: These findings question the test-retest reliability of the RPE scale when used to monitor subjective estimates of exercise intensity in progressive (or graded) exercise tests.

Adolescent↗

PubMed1999

Relationship between activity levels, aerobic fitness, and body fat in 8- to 10-yr-old children.

The relationships between children's activity, aerobic fitness, and fatness are unclear. Indirect estimates of activity, e.g., heart rate (HR) and recall, may mask any associations. The purpose of this study was to assess these relationships by using the Tritrac-R3D, a pedometer, and heart rate. Thirty-four children, ages 8-10 yr, participated in the study. The Tritrac and pedometer were worn for up to 6 days. HR was measured for 1 day. Activity measured by Tritrac or pedometer correlated positively to fitness in the whole group (Tritrac, r = 0.66; pedometer, r = 0.59; P < 0.01) and in boys and girls separately (P < 0.05) and correlated negatively to fatness in the whole group (r = -0.42, P < 0.05). In contrast, HR did not correlate significantly to fitness, and HR of >139 beats/min correlated positively to fatness in girls (r = 0.64, P < 0.05). This suggests that HR is misleading as a measure of activity. This study supports a positive relationship between activity and fitness and suggests a negative relationship between fatness and activity.

Adipose Tissue↗

PubMed1999

Exercise-induced muscle damage and potential mechanisms for the repeated bout effect.

Unfamiliar, predominantly eccentric exercise, frequently results in muscle damage. A repeated bout of similar eccentric exercise results in less damage and is referred to as the 'repeated bout effect'. Despite numerous studies that have clearly demonstrated the repeated bout effect, there is little consensus as to the actual mechanism. In general, the adaptation has been attributed to neural, connective tissue or cellular adaptations. Other possible mechanisms include, adaptation in excitation-contraction coupling or adaptation in the inflammatory response. The 'neural theory' predicts that the initial damage is a result of high stress on a relatively small number of active fast-twitch fibres. For the repeated bout, an increase in motor unit activation and/or a shift to slow-twitch fibre activation distributes the contractile stress over a larger number of active fibres. Although eccentric training results in marked increases in motor unit activation, specific adaptations to a single bout of eccentric exercise have not been examined. The 'connective tissue theory' predicts that muscle damage occurs when the noncontractile connective tissue elements are disrupted and myofibrillar integrity is lost. Indirect evidence suggests that remodelling of the intermediate filaments and/or increased intramuscular connective tissue are responsible for the repeated bout effect. The 'cellular theory' predicts that muscle damage is the result of irreversible sarcomere strain during eccentric contractions. Sarcomere lengths are thought to be highly non-uniform during eccentric contractions, with some sarcomeres stretched beyond myofilament overlap. Loss of contractile integrity results in sarcomere strain and is seen as the initial stage of damage. Some data suggest that an increase in the number of sarcomeres connected in series, following an initial bout, reduces sarcomere strain during a repeated bout and limits the subsequent damage. It is unlikely that one theory can explain all of the various observations of the repeated bout effect found in the literature. That the phenomenon occurs in electrically stimulated contractions in an animal model precludes an exclusive neural adaptation. Connective tissue and cellular adaptations are unlikely explanations when the repeated bout effect is demonstrated prior to full recovery, and when the fact that the initial bout does not have to cause appreciable damage in order to provide a protective effect is considered. It is possible that the repeated bout effect occurs through the interaction of various neural, connective tissue and cellular factors that are dependent on the particulars of the eccentric exercise bout and the specific muscle groups involved.

Adaptation, Physiological↗

PubMed1998

Validity of heart rate, pedometry, and accelerometry for predicting the energy cost of children's activities.

Heart rate telemetry is frequently used to estimate daily activity in children and to validate other methods. This study compared the accuracy of heart rate monitoring, pedometry, triaxial accelerometry, and uniaxial accelerometry for estimating oxygen consumption during typical children's activities. Thirty Welsh children (mean age 9.2 +/- 0.8 yr) walked (4 and 6 km/h) and ran (8 and 10 km/h) on a treadmill, played catch, played hopscotch, and sat and crayoned. Heart rate, body accelerations in three axes, pedometry counts, and oxygen uptake were measured continuously during each 4-min activity. Oxygen uptake was expressed as a ratio of body mass raised to the power of 0.75 [scaled oxygen uptake (sVO2)]. All measures correlated significantly (P < 0.001) with sVO2. A multiple-regression equation that included triaxial accelerometry counts and heart rate predicted sVO2 better than any measure alone (R2 = 0.85, standard error of the estimate = 9.7 ml.kg-0.75.min-1). The best of the single measures was triaxial accelerometry (R2 = 0.83, standard error of the estimate = 10.3 ml.kg-0.75.min-1). It is concluded that a triaxial accelerometer provides the best assessment of activity. Pedometry offers potential for large population studies.

Acceleration↗

PubMed1997

Pressure pain tolerance at different sites on the quadriceps femoris prior to and following eccentric exercise.

Downhill running, particularly for the untrained subject, is a mode of eccentric exercise that produces delayed-onset muscle soreness (DOMS) in the quadriceps femoris muscle which is maximal between 24 and 72 h after the exercise. It is not clear whether sensitivity to pain is uniform over the surface of the muscle, or whether some locations become more sensitive following eccentric exercise. The purpose of this investigation was to compare pressure pain tolerance (PPTO) at various sites on the quadriceps femoris muscle on 2 days prior to exercise, immediately after, and at 24, 48 and 72 h following a bout of eccentric exercise. Fifteen untrained female subjects performed a 40 min downhill run on a motorized treadmill with a gradient of -12%, where running speed was adjusted to elicit a heart rate of approximately 60% of age-related maximum heart rate reserve, and were measured for PPTO at seven sites on the right thigh. Sites were visited sequentially three times and repeated on each of 6 days. Pressure pain tolerance as an index of tenderness was determined using a strain gauge algometer. Two sites were close to the distal myotendinous junction, three sites were located on the mid belly of the muscle and two sites were located at the proximal myotendinous junction. There was a significant difference (p<0.01) in PPTO between muscle sites prior to eccentric exercise (Days 1 and 2), and a significant difference between sites following eccentric exercise (p<0.01). Sites close to the distal and proximal myotendinous junction were most sensitive to pain (p<0.01). There was no difference in PPTO at any site across the belly of the muscle. These results suggest that the belly of the quadriceps femoris is the most suitable area for measurement of PPTO.

Journal Article↗

PubMed1997

The effects of cryotherapy on muscle damage in rats subjected to endurance training.

Sixty 60-day-old Sprague-Dawley male rats were subjected to exhaustive and non-exhaustive exercise treatment over a period of 3, 5 and 7 weeks. Moderate exercise consisted of running on the treadmill at 10% grade at 10 m/min for 20 min for 5 days per week, while exhaustive running consisted of running at 10% grade at 15 m/min with an increase of 5 m/min every 5 min for 5 days per week. Half of the exercised rats were subjected to immersion in 4 degrees C water for 5 min after each exercise bout. Histological analyses of the gastrocnemius showed that ultrastructural damage of myofibrils occurred after 5 weeks of exhaustive running and 7 weeks of moderate running. With post-exercise immersion in 4 degrees C water for 5 min, the occurrence of ultrastructural damage advanced by 2 weeks in both treatments. It was concluded that the application of cryotherapy to the exercise groups was deleterious. Muscle damage occurred earlier in the treatment group and the degree of damage was also more serious over the same time period. This study supports the recommendation that the use of cryotherapy to reduce pain and haematoma formation should be coupled with rest for at least 48 hours.

Actin Cytoskeleton↗

PubMed1997

Use of ratings of perceived exertion for predicting maximal work rate and prescribing exercise intensity in patients taking atenolol.

OBJECTIVE: The purpose of this study was to assess the efficacy of Borg's rating of perceived exertion (RPE) scale to predict maximal exercise levels to control exercise intensity in patients taking atenolol for the treatment of essential hypertension. Normally, a standard formula (220-age) is used for calculating a percentage of exercise intensity, but beta blockade can cause reductions in maximal heart rate of between 20 and 30%. METHODS: Patients were split into a control group-10 men and 10 women, aged 50 (SD 12) and 46 (9) respectively, who had risk factors for cardiovascular disease but were not taking any drugs, and a treatment group-11 men and 11 women, aged 53 (13) and 55 (13) respectively, who were established on 25-100 mg of atenolol. All patients performed two submaximal tests on a cycle ergometer. Test 1 was an estimation test, during which the RPE was reported for each increment in work rate. Test 2 was an RPE production test, during which the patient regulated the work rate according to his/her perception of effort at four predetermined points on the RPE scale (RPE 9, 13, 15, 17). RESULTS: In both tests the individual correlations (r) between RPE, heart rate, and work rate ranged from 0.96 to 0.99. Analysis of variance showed no significant difference in maximal heart rate and maximal power output for the control group when predicted from the regression lines of RPE versus heart rate and RPE versus power output in the estimation test. However, the prediction of maximal power output was lower in the women in the control group and patients in the treatment group when this was predicted from the effort production protocol (P < 0.01). When exercise intensity at each RPE was expressed relative to maximal power output there were no differences between treatment and control groups. CONCLUSION: The findings from this study confirmed the strong positive relation between RPE, heart rate, and work rate in these patients in both passive effort estimation and active effort production protocols. However, caution in applying these procedures is required because the prediction of maximal exercise levels may be lower when effort production procedures are used.

Adrenergic beta-Antagonists↗

PubMed1997

Effort perception in children.

Studies addressing children's perceptions of exercise effort have appeared steadily in the scientific literature over the last 20 years, though they have been relatively sparse in number. With little or no regard for their suitability, researchers initially applied to children the methods and applications of the rating of perceived exertion (RPE) notion established amongst adults. Whilst some success was claimed, findings were inconclusive, possibly because of the use of an inappropriate measurement scale. More recently, the development of the child-specific Children's Effort Rating Table (CERT) has advanced research in this domain and helped to focus attention on the numerous problems of applying this psychophysical concept to such immature subjects. Accordingly, the scope for further research in this discipline is now far broader than ever before.

Child↗