Longitudinal lung function in urban firefighters: A group-based multi-trajectory modelling approach.

BACKGROUND AND OBJECTIVE: Urban firefighters are routinely exposed to both physical and chemical hazards that can negatively impact lung health, but it is unclear if firefighters experience accelerated decline in spirometry parameters due to chronic exposure and acute insults. This study aimed to describe sub-groups of firefighters with differing spirometry trajectories and examine the relationship between the identified trajectories and demographic, lifestyle and occupational characteristics. METHODS: Data from six waves of the Respiratory Function Measurement and Surveillance for South Australian Metropolitan Fire Service Study (2007-2019) were used to identify spirometry parameter z-score trajectories, using group-based multi-trajectory modelling (GBMTM). Analysis of variance and chi-square statistics were used to assess trajectory group differences in baseline self-reported demographic, lifestyle and occupational characteristics. RESULTS: In the 669 included firefighters, we identified five trajectories for the combination of Forced Expiratory Volume in the first second z-score (FEV1 z), Forced Vital Capacity z-score (FVCz) and the ratio of FEV1 and FVC z-score (FEV1 /FVCz). There were three stable trajectories of low, average and very high lung function and two declining trajectories of average and high lung function. Analysis of subgroup characteristics revealed no significant differences between expected and actual group proportions for the occupational characteristics of years of service and respiratory protection use. Significant differences were seen in respiratory health and body mass index. CONCLUSION: GBMTM defined distinct, plausible spirometry trajectory sub-groups. Firefighter longitudinal spirometry trajectory group membership was associated with BMI and respiratory disease or symptoms but not with self-reported smoking history or occupational factors.

Ratings of perceived exertion from a submaximal 20-m shuttle run test predict peak oxygen uptake in children and the test feels better.

PURPOSE: To determine the validity and test-retest reliability of using ratings of perceived exertion (RPE) elicited during a submaximal 20-m Shuttle Run Test (20mSRT) to predict VO2peak in children and investigate acute affective responses. METHODS: Twenty-five children (14 boys; age, 12.8 ± 0.7 years; height, 162.0 ± 9.3 cm; mass, 49.9 ± 7.7 kg) completed four exercise tests (GXT, 2 submaximal 20mSRT, maximal 20mSRT). The Eston-Parfitt RPE scale was used, and affect was measured with the Feeling Scale. Submaximal 20mSRT were terminated upon participants reporting RPE7. The speed-RPE relationship from the submaximal 20mSRTs was extrapolated to RPE9 and 10 to predict peak speed and then used to estimate VO2peak. RESULTS: Repeated measures ANOVA to examine the validity of using submaximal RPE to predict VO2peak resulted in a Gender main effect (boys = 46.7 ± 5.1 mL kg-1 min-1; girls = 42.0 ± 5.1 mL kg-1 min-1) and Method main effect (p < 0.01). There were significant differences between measured and estimated VO2peak from the maximal 20mSRT, but not between measured and estimated VO2peak at RPE9 and RPE10. Intraclass correlation analysis revealed excellent reliability (~ 0.9) between the two submaximal 20mSRTs. Significant differences (p < 0.05) in end-test affect were reported between submaximal and maximal trials in girls, but not in boys, with girls feeling less negative at the end of the submaximal trials. CONCLUSIONS: The results of this study provide evidence that RPE reported during a submaximal 20mSRT can be used to predict VO2peak accurately and reliably. In this study, the submaximal 20mSRT ending at RPE7, provided better predictions of VO2peak while minimising aversive end-point affect, especially in girls.

Oxygen uptake and heart rate responses to 4 weeks of RPE-guided handcycle training.

PURPOSE: To investigate the efficacy of using Ratings of Perceived Exertion (RPE) to prescribe and regulate a 4-week handcycle training intervention. METHODS: Thirty active adults, untrained in upper body endurance exercise, were divided into three groups to complete a 4-week intervention: (i) RPE-guided training (n = 10; 2 female), (ii) power output (PO)-guided (n = 10; 2 female) training, or (iii) non-training control (n = 10; 4 female). Training groups performed three sessions of handcycling each week. Oxygen uptake ([Formula: see text]), heart rate (HR), and Feeling Scale (FS) rating were collected during training sessions. RPE-guided training was performed at RPE 13. PO-guided training was matched for percentage of peak PO per session, based upon that achieved by the RPE-guided training group. RESULTS: There were no differences in percentage of peak [Formula: see text] (66 ± 13% vs 61 ± 9%, p = 0.22), peak HR (75 ± 8% vs 71 ± 6%, p = 0.11) or FS rating (1.2 ± 1.9 vs 0.8 ± 1.6, p = 0.48) between RPE- and PO-guided training, respectively. The average coefficient of variation in percentage of peak HR between consecutive training sessions was 2.8% during RPE-guided training, and 3.4% during PO-guided training. CONCLUSION: Moderate-vigorous intensity handcycling exercise can be prescribed effectively using RPE across a chronic training intervention, suggesting utility for practitioners in a variety of rehabilitation settings.

What is the effect of aerobic exercise intensity on cardiorespiratory fitness in those undergoing cardiac rehabilitation? A systematic review with meta-analysis.

OBJECTIVE: Assess the role of exercise intensity on changes in cardiorespiratory fitness (CRF) in patients with cardiac conditions attending exercise-based cardiac rehabilitation. DESIGN: Systematic review with meta-analysis. DATA SOURCES: MEDLINE, Embase, CINAHL, SPORTDiscus, PsycINFO and Web of Science. ELIGIBILITY CRITERIA FOR SELECTION: Studies assessing change in CRF (reported as peak oxygen uptake; V̇O2peak) in patients post myocardial infarction and revascularisation, following exercise-based cardiac rehabilitation. Studies establishing V̇O2peak via symptom-limited exercise test with ventilatory gas analysis and reported intensity of exercise during rehabilitation were included. Studies with mean ejection fraction <40% were excluded. RESULTS: 128 studies including 13 220 patients were included. Interventions were classified as moderate, moderate-to-vigorous or vigorous intensity based on published recommendations. Moderate and moderate-to-vigorous-intensity interventions were associated with a moderate increase in relative V̇O2peak (standardised mean difference±95% CI=0.94±0.30 and 0.93±0.17, respectively), and vigorous-intensity exercise with a large increase (1.10±0.25). Moderate and vigorous-intensity interventions were associated with moderate improvements in absoluteV̇O2peak (0.63±0.34 and 0.93±0.20, respectively), whereas moderate-to-vigorous-intensity interventions elicited a large effect (1.27±0.75). Large heterogeneity among studies was observed for all analyses. Subgroup analyses yielded statistically significant, but inconsistent, improvements in CRF. CONCLUSION: Engagement in exercise-based cardiac rehabilitation was associated with significant improvements in both absolute and relative V̇O2peak. Although exercise of vigorous intensity produced the greatest pooled effect for change in relative V̇O2peak, differences in pooled effects between intensities could not be considered clinically meaningful. REGISTRATION: Prospero CRD42016035638.

Peak oxygen uptake measured during a perceptually-regulated exercise test is reliable in community-based manual wheelchair users.

This study compares test-retest reliability and peak exercise responses from ramp-incremented (RAMP) and maximal perceptually-regulated (PRETmax) exercise tests during arm crank exercise in individuals reliant on manual wheelchair propulsion (MWP). Ten untrained participants completed four trials over 2-weeks (two RAMP (0-40 W + 5-10 W · min-1) trials and two PRETmax. PRETmax consisted of five, 2-min stages performed at Ratings of Perceived Exertion (RPE) 11, 13, 15, 17 and 20). Participants freely changed the power output to match the required RPE. Gas exchange variables, heart rate, power output, RPE and affect were determined throughout trials. The V̇O2peak from RAMP (14.8 ± 5.5 ml · kg-1 · min-1) and PRETmax (13.9 ± 5.2 ml · kg-1 · min-1) trials were not different (P = 0.08). Measurement error was 1.7 and 2.2 ml · kg-1 · min-1 and coefficient of variation 5.9% and 8.1% for measuring V̇O2peak from RAMP and PRETmax, respectively. Affect was more positive at RPE 13 (P = 0.02), 15 (P = 0.01) and 17 (P = 0.01) during PRETmax. Findings suggest that PRETmax can be used to measure V̇O2peak in participants reliant on MWP and leads to a more positive affective response compared to RAMP.

Inter- and Intra-rater Reliability of the Athletic Ability Assessment in Subelite Australian Rules Football Players.

Rogers, DK, McKeown, I, Parfitt, G, Burgess, D, and Eston, RG. Inter- and intra-rater reliability of the athletic ability assessment in subelite Australian rules football players. J Strength Cond Res 33(1): 125-138, 2019-The aim of this study was to determine the inter- and intra-rater rater reliability of the Athletic Ability Assessment (AAA) in subelite Australian Rules football (ARF) players. Eighteen male ARF players completed the AAA movement assessment (overhead squat, double lunge [left and right], single-leg Romanian deadlift [left and right], chin-up and push-up), on 2 occasions separated by 1 week. During the first movement assessment, players were filmed in the frontal and sagittal planes. Ten raters took part in the study (1 experienced rater and 9 novices) and were assigned in a quasirandom manner, to complete either (a) real-time assessment on 2 occasions, (b) real-time assessment on 1 occasion, or (c) video-based assessment on 2 occasions. When assessed in real-time, of the 7 component movements of the AAA, raters registered moderate or greater intrarater agreement on between 2 and 5 occasions. Intraclass correlation coefficients (ICCs) of between 0.50 and 0.61 for the AAA total score indicated poor real-time intrarater reliability for this variable. When assessed by video-recording, raters registered moderate or greater intrarater agreement on between 6 and 7 occasions. The ICC for total score ranged between 0.60 and 0.93. Overall poor interrater reliability was evident for AAA component movements regardless of whether it was assessed in real-time or from video. Findings suggest the AAA is most reliably used when assessed through video. It is recommended that if comparison between multiple raters is desired, a stringent training process be applied so that the interpretation of AAA scoring criteria is standardized across raters.

Submaximal Exercise-Based Equations to Predict Maximal Oxygen Uptake in Older Adults: A Systematic Review.

OBJECTIVE: To evaluate and discuss the accuracy of submaximal exercise-based equations to predict maximum oxygen uptake (V˙o2max), validated using direct gas analysis, in older apparently healthy adults. DATA SOURCES: Studies were identified by searching 5 electronic databases and manually scanning reference lists of included articles from the respective inception of each database through April 2015. STUDY SELECTION: Studies were included if they used at least 1 submaximal exercise-based variable in the prediction, the actual V˙o2max was directly measured using a gas analysis device, and if participants were apparently healthy older adults (mean age ≥65y). Eligible studies were required to report at least 1 validity statistic (eg, Pearson product-moment correlation [r]) and either a predicted and measured V˙o2max value or a directional significant difference between the measured and predicted V˙o2max values. No limits were placed on year of publication, but only full-text, published articles in the English language were included. DATA EXTRACTION: Nine articles and 13 equations were retained from the systematic search strategy. If the same prediction equation was used across multiple trials, data from the most accurate trial were reported. DATA SYNTHESIS: Submaximal equations predicted directly measured V˙o2max with a moderate to strong correlation strength (r range, 0.4-0.9). Predicted V˙o2max significantly differed from directly measured in 2 of the 13 equations. The preferred mode of ergometry was walking or running (7 equations); a stepping protocol was the most accurate (R(2)=0.9, not significant between predicted and measured V˙o2max). CONCLUSIONS: Factors to consider when choosing a submaximal exercise-based equation are the accuracy of the equation, the population tested, the mode of ergometry, the equipment availability, and the time needed to conduct familiarization sessions.

Prediction of peak oxygen uptake in children using submaximal ratings of perceived exertion during treadmill exercise.

PURPOSE: This study assessed the utility of the Children's Effort Rating Table (CERT) and the Eston-Parfitt (EP) Scale in estimating peak oxygen uptake ([Formula: see text]) in children, during cardiopulmonary exercise testing (CPET) on a treadmill. METHODS: Fifty healthy children (n = 21 boys; 9.4 ± 0.9 years) completed a continuous, incremental protocol until the attainment of [Formula: see text]. Oxygen uptake ([Formula: see text]) was measured continuously, and ratings of perceived exertion (RPE) were estimated at the end of each exercise stage using the CERT and the EP Scale. Ratings up to- and including RPE 5 and 7, from both the CERT (CERT 5, CERT 7) and EP Scale (EP 5, EP 7), were linearly regressed against the corresponding [Formula: see text], to both maximal RPE (CERT 10, EP 10) and terminal RPE (CERT 9, EP 9). RESULTS: There were no differences between measured- and predicted [Formula: see text] from CERT 5, CERT 7, EP 5 and EP 7 when extrapolated to either CERT 9 or EP 9 (P > 0.05). Pearson's correlations of r = 0.64-0.86 were observed between measured- and predicted [Formula: see text], for all perceptual ranges investigated. However, only EP 7 provided a small difference when considering the standard error of estimate, suggesting that the prediction of [Formula: see text] from EP 7 would be within 10 % of measured [Formula: see text]. CONCLUSIONS: Although robust estimates of [Formula: see text] may be elicited using both the CERT and EP Scale during a single CPET with children, the most accurate estimates of [Formula: see text] occur when extrapolating from EP 7.

Validity of a perceptually-regulated step test protocol for assessing cardiorespiratory fitness in healthy adults.

PURPOSE: To determine whether maximal oxygen uptake (VO2max) could be predicted accurately and reliably from a 2-step, perceptually-regulated exercise test (PRET) in healthy adults. METHODS: Sixteen participants (31.7 ± 11.3 years, 3 females) completed three PRETs (separated by 24-72 h) and one maximal, perceptually-regulated, graded exercise test (PRETmax) on a motorized treadmill. Oxygen uptake (VO2) and heart rate (HR) were recorded during each test. VO2 values for RPE range 9-15 were extrapolated to RPE 20 and age-predicted maximal HR (HRmax) using individual linear regression analysis to predict VO2max values compared to measured VO2max. RESULTS: VO2 and HR values were consistent between each of four RPE levels of the PRET. ICC values ranged between 0.76 and 0.85. Predicted VO2max from both methods were lower than measured VO2max (p < 0.01). Limits of agreement (LoA) for measured (41.4 ± 5.3 ml kg-1 min-1) versus predicted VO2max from each of the three PRETs using RPE20 were -1.2 ± 15.6, -1.0 ± 7.2 and -2.1 ± 5.5 and for HRmax were -1.8 ± 4.2; -2.6 ± 4.2 and -2.4 ± 4.4 ml kg-1 min-1 for PRET 1, 2 and 3, respectively. CONCLUSIONS: The step PRET elicited significant and reliable increases in VO2 across the four RPE levels, but under-estimated treadmill VO2max. However, there was better agreement between measured and predicted VO2max when extrapolated to HRmax. As evidence indicates the underestimation of VO2max is explained by the difference in the mode of exercise, the step PRET provides a simple and convenient test of cardiorespiratory fitness.

Coordination of digit force variability during dominant and non-dominant sustained precision pinch.

This study examined the effects of handedness on the inter-digit coordination of force variability with and without concurrent visual feedback during sustained precision pinch. Twenty-four right-handed subjects were instructed to pinch an instrumented apparatus with their dominant and non-dominant hands, separately. During the pinch, the subjects were required to maintain a stable force output at 5 N for 1 min. Visual feedback was given for the first 30 s and removed for the second 30 s. Coefficient of variation and detrended fluctuation analysis were employed to examine the amount and structural variability of the thumb and index finger forces. Similarly, correlation coefficient and detrended cross-correlation analysis were applied to quantify the inter-digit correlation of force amount and structural variability. Results showed that, compared to the non-dominant hand, the dominant hand had higher inter-digit difference in the amount of digit force variability. Without visual feedback, the dominant hand exhibited lower digit force structural variability but higher inter-digit force structural correlation than the non-dominant hand. These results implied that the dominant hand would be more independent, less flexible and with lower dynamic degrees of freedom than the non-dominant hand in coordination of the thumb and index finger forces during sustained precision pinch. The effects of handedness on inter-digit force coordination were dependent on sensory condition, which shed light on higher-level sensorimotor mechanisms that may be responsible for the asymmetries in coordination of digit force variability.

Patterning of physiological and affective responses in older active adults during a maximal graded exercise test and self-selected exercise.

PURPOSE: The American College of Sports Medicine has highlighted the importance of considering the physiological and affective responses to exercise when setting exercise intensity. Here, we examined the relationship between exercise intensity and physiological and affective responses in active older adults. METHOD: Eighteen participants (60-74 years; 64.4 ± 3.9; 8 women) completed a maximal graded exercise test (GXT) on a treadmill. Since time to exhaustion in the GXT differed between participants, heart rate (HR), oxygen consumption (VO2), affective valence (affect) and rating of perceived exertion (RPE) were expressed relative to the individually determined ventilatory threshold (%atVT). RESULT: During the GXT, VO2, HR and RPE increased linearly (all P < 0.01). Affect declined initially (but remained positive) (P = 0.03), stabilised around VT (still positive) (P > 0.05) and became negative towards the end of the test (P < 0.01). In a subsequent session, participants completed a 20-min bout of self-selected exercise (at a preferred intensity). Initially, participants chose to exercise below VT (88.2 ± 17.4 %VO2atVT); however, the intensity was adjusted to work at, or above VT (107.7 ± 19.9 %VO2atVT) after 10 min (P < 0.001), whilst affect remained positive. CONCLUSION: Together, these findings indicate that exercise around VT, whether administered during an exercise test, or self-selected by the participant, is likely to result in positive affective responses in older adults.

Prediction of peak oxygen uptake from ratings of perceived exertion during a sub-maximal cardiopulmonary exercise test in patients with chronic obstructive pulmonary disease.

PURPOSE: We assessed the validity of predicting peak oxygen uptake ([Formula: see text]O2 peak) from the relationship between oxygen uptake ([Formula: see text]O2) and overall ratings of perceived exertion (RPE) obtained during the initial stages of a cardiopulmonary exercise test (CPET). METHOD: Fifteen healthy participants and 18 patients with chronic obstructive pulmonary disease (COPD) performed a maximal CPET, during which [Formula: see text]O2 and RPE were measured until RPE15. RESULTS: Individual regressions between [Formula: see text]O2 and RPE ≤ 15 were extrapolated to RPE19 to predict [Formula: see text]O2 peak. Mean actual and predicted [Formula: see text]O2 peak were not significantly different in healthy women (18.9 ± 4.1 vs. 20.4 ± 4.5 mL kg(-1) min(-1), respectively) and men (28.9 ± 7.8 vs. 29.7 ± 8.5 mL kg(-1) min(-1), respectively), or in women (15.2 ± 4.7 vs. 15.8 ± 5.0 mL kg(-1) min(-1), respectively) and men (16.2 ± 4.4 vs. 17.4 ± 5.4 mL kg(-1) min(-1), respectively) with COPD (P = 0.067). Moreover, actual and predicted [Formula: see text]O2 peak were highly correlated in healthy participants and COPD patients (r ≥ 0.89; P < 0.001). The bias and 95 % limits of agreement were -1.0 ± 4.0 and -1.0 ± 4.6 mL kg(-1) min(-1) for healthy and COPD participants, respectively. CONCLUSION: [Formula: see text]O2 peak can be predicted with acceptable accuracy in healthy participants and patients with COPD from the individual relationship between [Formula: see text]O2 and RPE ≤ 15.

A perceptually-regulated exercise test predicts peak oxygen uptake in older active adults.

Peak oxygen uptake (VO2peak) is reliably predicted in young and middle-aged adults using a submaximal perceptually-regulated exercise test (PRET). It is unknown whether older adults can use a PRET to accurately predict VO2peak. In this study, the validity of a treadmill-based PRET to predict VO2peak was assessed in 24 participants (65.2 ± 3.9 years, 11 males). The PRET required a change in speed or incline corresponding to ratings of perceived exertion (RPE) 9, 11, 13, and 15. Extrapolation of submaximal VO2 from the PRET to RPE endpoints 19 and 20 and age-predicted HRmax were compared with measured VO2peak. The VO2 extrapolated to both RPE19 and 20 over-predicted VO2peak (p < .001). However, extrapolating VO2 to age-predicted HRmax accurately predicted VO2peak (r = .84). Results indicate older adults can use a PRET to predict VO2peak by extrapolating VO2 from submaximal intensities to an age-predicted HRmax.

A hard/heavy intensity is too much: The physiological, affective, and motivational effects (immediately and 6 months post-training) of unsupervised perceptually regulated training.

BACKGROUND/OBJECTIVE: There are several practical and theoretical advantages to perceptually regulated training, including its simplicity of use and potential to influence exercise motivation. The study objective was to examine if perceptually regulated training at ratings of perceived exertion (RPE) of 13 and 15 resulted in significant increases in aerobic fitness, reductions in metabolic risk factors, and changes in motivational constructs following an 8-week training program and at follow up 6 months after. METHODS: Following stratified randomization based on estimated aerobic capacity and sex, sedentary volunteers (n = 63; men = 21) were allocated to one of three groups: RPE 13, RPE 15, and control. The participants completed baseline, post-training, and 6-months post-training assessments for aerobic fitness, metabolic risk factors, and motivational constructs. The participants' acute exercise training responses (affect, competence, enjoyment, and work rate) were also recorded. RESULTS: The data support the fitness and motivational construct hypotheses but not the metabolic risk factor hypothesis. Aerobic fitness increased from the baseline to post-training in both RPE groups, with the increase maintained 6 months post-training only in the RPE 13 group. Exercise autonomy increased over the training program, with exercise competence and affect more positive in the RPE 13 group than in the RPE 15. However, the training programs did not reduce the metabolic risk factors, and attrition levels were high. Unsupervised training at RPE 13 and RPE 15 did improve fitness, but as hypothesized, this was not maintained in the RPE 15 group 6 months post-training. CONCLUSION: The motivational processes associated with RPE 13 regulated exercise (greater competence and autonomy and more positive affect) potentially explain the maintained fitness in this group.

Prediction of peak oxygen uptake from differentiated ratings of perceived exertion during wheelchair propulsion in trained wheelchair sportspersons.

PURPOSE: To assess the validity of predicting peak oxygen uptake (VO(2peak)) from differentiated ratings of perceived exertion (RPE) obtained during submaximal wheelchair propulsion. METHODS: Three subgroups of elite male wheelchair athletes [nine tetraplegics (TETRA), nine paraplegics (PARA), eight athletes without spinal cord injury (NON-SCI)] performed an incremental speed exercise test followed by graded exercise to exhaustion (VO(2peak) test). Oxygen uptake (VO2), heart rate (HR) and differentiated RPE (Central RPE(C), Peripheral RPE(P) and Overall RPE(O)) were obtained for each stage. The regression lines for the perceptual ranges 9-15 on the Borg 6-20 scale ratings were performed to predict VO(2peak). RESULTS: There were no significant within-group mean differences between measured VO(2peak) (mean 1.50 ± 0.39, 2.74 ± 0.48, 3.75 ± 0.33 L min(-1) for TETRA, PARA and NON-SCI, respectively) and predicted VO(2peak) determined using HR or differentiated RPEs for any group (P > 0.05). However, the coefficients of variation (CV %) between measured and predicted VO(2peak) using HR showed high variability for all groups (14.3, 15.9 and 9.7%, respectively). The typical error ranged from 0.14 to 0.68 L min(-1) and the CV % between measured and predicted VO(2peak) using differentiated RPE was ≤11.1% for TETRA, ≤7.5% for PARA and ≤20.2% for NON-SCI. CONCLUSIONS: Results suggest that differentiated RPE may be used cautiously for TETRA and PARA athletes when predicting VO(2peak) across the perceptual range of 9-15. However, predicting VO(2peak) is not recommended for the NON-SCI athletes due to the large CV %s (16.8, 20.2 and 18.0%; RPE(C), RPE(P) and RPE(O), respectively).

A systematic review and meta-analysis of submaximal exercise-based equations to predict maximal oxygen uptake in young people.

Many equations to predict maximal oxygen uptake (VO2max) from submaximal exercise tests have been proposed for young people, but the composition and accuracy of these equations vary greatly. The purpose of this systematic review was to analyze all submaximal exercise-based equations to predict VO2max measured via direct gas analysis for use with young people. Five databases were systematically searched in February 2013. Studies were included if they used a submaximal, exercise-based method to predict VO2max; the actual VO2max was gas analyzed; participants were younger than 18 years; and equations included at least one submaximal exercise-based variable. A meta-analysis and narrative synthesis were conducted. Sixteen studies were included. The mean equation validity statistic was strong, r = .786 (95% CI 0.747-0.819). Subgroup meta-analysis suggests exercise mode may contribute to the overall model, with running- and walking-based predictive equations reporting the highest mean r values (running r = .880; walking r = .821) and cycling the weakest (r = .743). Selection of the most appropriate equation should be guided by factors such as purpose, logistic limitations, appropriateness of the validation sample, the level of study bias, and the degree of accuracy. Suggestions regarding the most accurate equation for each exercise mode are provided.

Heart rate and perceived muscle pain responses to a functional walking test in McArdle disease.

The aim of this study was to assess a 12-min self-paced walking test in patients with McArdle disease. Twenty patients (44.7 ± 11 years; 11 female) performed the walking test where walking speed, distance walked, heart rate (HR) and perceived muscle pain (Borg CR10 scale) were measured. Median (interquartile range) distance walked was 890 m (470-935). From 1 to 6 min, median walking speed decreased (from 75.0 to 71.4 m∙min(-1)) while muscle pain and %HR reserve increased (from 0.3 to 3.0 and 37% to 48%, respectively). From 7 to 12 min, walking speed increased to 74.2 m∙min(-1), muscle pain decreased to 1.6 and %HR reserve remained between 45% and 48%. To make relative comparisons, HR and muscle pain were divided by walking speed and expressed as ratios. These ratios rose significantly between 1 and 6 min (HR:walking speed P = .001 and pain:walking speed P < .001) and similarly decreased between 6 and 11 min (P = .002 and P = .001, respectively). Peak ratios of HR:walking speed and pain:walking speed were inversely correlated to distance walked: rs (HR) = -.82 (P < .0001) and rs (pain) = -.55 (P = .012). Largest peak ratios were found in patients who walked < 650 m. A 12-min walking test can be used to assess exercise capacity and detect the second wind in McArdle disease.

Differentiated perceived exertion and self-regulated wheelchair exercise.

OBJECTIVE: To investigate the utility of the differentiated rating of perceived exertion (RPE) for the self-regulation of submaximal wheelchair propulsion in novice users. DESIGN: Each participant completed a submaximal incremental test and a graded test to exhaustion to determine peak oxygen consumption (Vo(2)peak) on a wheelchair ergometer. On a separate day, two 12-minute intermittent bouts consisting of three 4-minute stages were completed at individualized imposed power outputs equating to light (40% Vo(2)peak) and moderate (60% Vo(2)peak) intensity exercise. On a third occasion, participants were assigned to either the overall group or the peripheral group and were required to self-regulate 12-minute intermittent exercise according to either overall RPE or peripheral RPE reported during the corresponding imposed intensity trial. SETTING: Laboratory facilities at a university. PARTICIPANTS: Preliminary population of able-bodied participants with no prior experience of wheelchair propulsion (N=18). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Differences in oxygen consumption (Vo(2)), heart rate, blood lactate concentration, and power output between the imposed and self-regulated exercise trials. RESULTS: No difference was found in physiological responses between the moderate-intensity imposed and RPE-regulated trials in the peripheral group, whereas a significant (P<.05) underproduction in Vo(2) (1.76±.31 vs 1.59±.25L/min) and blood lactate concentration (2.8±0.90 vs 2.21±.83mmol/L) was seen in the overall group. In contrast, a significant (P<.05) overproduction was seen in the peripheral group at a light exercise intensity, whereas no difference was found between all variables during the light-intensity imposed and RPE-regulated trials in the overall group. CONCLUSIONS: Peripheral RPE enabled a more precise self-regulation during moderate-intensity wheelchair exercise in novice users. In contrast, overall RPE provided a more accurate stimulus when performing light-intensity propulsion.

The perceptually regulated exercise test is sensitive to increases in maximal oxygen uptake.

The aim of this study was to assess the sensitivity of a perceptually regulated exercise test (PRET) to predict maximal oxygen uptake (VO2max) following an aerobic exercise-training programme. Sedentary volunteers were assigned to either a training (TG n = 16) or control (CG n = 10) group. The TG performed 30 min of treadmill exercise, regulated at 13 on the Borg Rating of Perceived Exertion (RPE) Scale, 3× per week for 8 weeks. All participants completed a 12-min PRET to predict VO2max followed by a graded exercise test (GXT) to measure VO2max before and after training. The PRET required participants to control the speed and incline on the treadmill to correspond to RPE intensities of 9, 11, 13 and 15. Predictive accuracy of extrapolation end-points RPE19 and RPE20 from a submaximal RPE range of 9-15 was compared. Measured VO2max increased by 17 % (p < 0.05) from baseline to post-intervention in TG. This was reflected by a similar change in [VO2max predicted from PRET when extrapolated to RPE 19 (baseline VO2max: 31.3 ± 5.5, 30.3 ± 9.5 mL kg(-1) min(-1); post-intervention VO2max: 36.7 ± 6.4, 37.4 ± 7.9 mL kg(-1) min(-1), for measured and predicted values, respectively). There was no change in CG (measured vs. predicted VO2max: 39.3 ± 6.5; 40.3 ± 8.2 and 39.2 ± 7.0; 37.7 ± 6.0 mL kg(-1) min(-1)) at baseline and post-intervention, respectively. The results confirm that PRET is sensitive to increases in VO2max following aerobic training.