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

Ratings of perceived exertion (RPE) from a submaximal 20-m shuttle-run test accurately predict children's VO2peak, but when should we stop the test?

PURPOSE

The purpose of the study was to explore the validity, test-retest reliability and affective responses of a submaximal 20-m shuttle-run test (20mSRT) stopped at 6 on the Eston-Parfitt (EP) scale. The secondary aim was to examine and compare two submaximal 20mSRT protocols with different RPE end points (EP6 vs. EP7) using previously published data.

METHODS

Twenty-five children (16 boys; 13.4 ± 1.0 years; 162.1 ± 8.7 cm; 49.1 ± 6.6 kg) completed three exercise tests (graded exercise test [GXT], 2 submaximal 20mSRT). The EP scale and Feeling scale were used to measure RPE and affect, respectively. The two submaximal 20mSRTs were stopped after participants reported EP6. Individual speed-RPE relationships from the submaximal 20mSRTs were linearly regressed to predict peak speed and then used to estimate VO2peak. Previously published data (n = 25) used comparable methods, except that the participants stopped at EP7.

RESULTS

In the EP6 protocol, a two-factor repeated measures ANOVA revealed non-significant Test and Sex main effects (p > 0.05). Reliability analysis revealed intraclass correlation coefficient of ~ 0.7 (95%CI [0.432,0.867], p < 0.001) between the submaximal 20mSRTs. Significant differences in end-test affect between the GXT and submaximal 20mSRTs were found (p < 0.001), with GXT more negative. ANOVA revealed no significant differences in end-test affect between EP6 and EP7 protocols; however, frequency count analysis revealed EP6 to result in more positive end-test affect.

CONCLUSION

Submaximal 20mSRT utilising RPE may offer valid predictions in VO2peak while minimising negative affect. Test end points of EP6 and EP7 both offer valid predictions in VO2peak. EP6 may be more beneficial in avoiding negative affect, even though a reduction in test-retest reliability was observed.

Confirming the attainment of maximal oxygen uptake within special and clinical groups: A systematic review and meta-analysis of cardiopulmonary exercise test and verification phase protocols

BACKGROUND AND AIM

A plateau in oxygen uptake ([Formula: see text]) during an incremental cardiopulmonary exercise test (CPET) to volitional exhaustion appears less likely to occur in special and clinical populations. Secondary maximal oxygen uptake ([Formula: see text]) criteria have been shown to commonly underestimate the actual [Formula: see text]. The verification phase protocol might determine the occurrence of 'true' [Formula: see text] in these populations. The primary aim of the current study was to systematically review and provide a meta-analysis on the suitability of the verification phase for confirming 'true' [Formula: see text] in special and clinical groups. Secondary aims were to explore the applicability of the verification phase according to specific participant characteristics and investigate which test protocols and procedures minimise the differences between the highest [Formula: see text] values attained in the CPET and verification phase.

METHODS

Electronic databases (PubMed, Web of Science, SPORTDiscus, Scopus, and EMBASE) were searched using specific search strategies and relevant data were extracted from primary studies. Studies meeting inclusion criteria were systematically reviewed. Meta-analysis techniques were applied to quantify weighted mean differences (standard deviations) in peak [Formula: see text] from a CPET and a verification phase within study groups using random-effects models. Subgroup analyses investigated the differences in [Formula: see text] according to individual characteristics and test protocols. The methodological quality of the included primary studies was assessed using a modified Downs and Black checklist to obtain a level of evidence. Participant-level [Formula: see text] data were analysed according to the threshold criteria reported by the studies or the inherent measurement error of the metabolic analysers and displayed as Bland-Altman plots.

RESULTS

Forty-three studies were included in the systematic review, whilst 30 presented quantitative information for meta-analysis. Within the 30 studies, the highest mean [Formula: see text] values attained in the CPET and verification phase protocols were similar (mean difference = -0.00 [95% confidence intervals, CI = -0.03 to 0.03] L·min-1, p = 0.87; level of evidence, LoE: strong). The specific clinical groups with sufficient primary studies to be meta-analysed showed a similar [Formula: see text] between the CPET and verification phase (p > 0.05, LoE: limited to strong). Across all 30 studies, [Formula: see text] was not affected by differences in test protocols (p > 0.05; LoE: moderate to strong). Only 23 (53.5%) of the 43 reviewed studies reported how many participants achieved a lower, equal, or higher [Formula: see text] value in the verification phase versus the CPET or reported or supplied participant-level [Formula: see text] data for this information to be obtained. The percentage of participants that achieved a lower, equal, or higher [Formula: see text] value in the verification phase was highly variable across studies (e.g. the percentage that achieved a higher [Formula: see text] in the verification phase ranged from 0% to 88.9%).

CONCLUSION

Group-level verification phase data appear useful for confirming a specific CPET protocol likely elicited [Formula: see text], or a reproducible [Formula: see text], for a given special or clinical group. Participant-level data might be useful for confirming whether specific participants have likely elicited [Formula: see text], or a reproducible [Formula: see text], however, more research reporting participant-level data is required before evidence-based guidelines can be given.

TRIAL REGISTRATION

PROSPERO (CRD42021247658) https://www.crd.york.ac.uk/prospero.

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 VO_2peak 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 VO_2peak.

RESULTS

Repeated measures ANOVA to examine the validity of using submaximal RPE to predict VO_2peak 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 VO_2peak from the maximal 20mSRT, but not between measured and estimated VO_2peak 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 VO_2peak accurately and reliably. In this study, the submaximal 20mSRT ending at RPE7, provided better predictions of VO_2peak while minimising aversive end-point affect, especially in girls.

The Use of Ratings of Perceived Exertion in Children and Adolescents: A Scoping Review

In adults, ratings of perceived exertion (RPE) can be used to predict maximal oxygen uptake, estimate time to exhaustion, assess internal training load and regulate exercise intensity. However, the utility of RPE in children is less researched and therefore, warrants investigation. The purpose of this scoping review is to map out the literature around the application of RPE specifically during aerobic exercise in paediatric populations. Seven bibliographic databases were systematically searched. Grey literature searching and pearling of references were also conducted. To be included for the review, studies were required to comply with the following: (1) participants aged ≤ 18 years asymptomatic of any injuries, disabilities or illnesses; (2) applied RPE in aerobic exercise, testing and/or training; (3) included at least one measure of exercise intensity; and (4) be available in English. The search identified 22 eligible studies that examined the application of RPE in children. These studies involved a total of 718 participants across ten different countries. Nine different types of RPE scales were employed. Overall, the application of RPE in paediatric populations can be classified into three distinct themes: prediction of cardiorespiratory fitness/performance, monitoring internal training loads, and regulation of exercise intensity. The utility of RPE in paediatric populations remains unclear due to the small body of available research and inconsistencies between studies. However, findings from the included studies in this scoping review may show promise. Further research focussing on child-specific RPE scales across various sports, subgroups, and in field-based settings is needed.

The Predictability of Peak Oxygen Consumption Using Submaximal Ratings of Perceived Exertion in Adolescents

Rating of perceived exertion (RPE) extrapolation involves mathematically extending the submaximal relationship between RPE and oxygen consumption (VO2) to maximal intensity. This technique allows practitioners to forego, potentially dangerous, maximal exertion testing while attaining accurate measures of maximal oxygen consumption used for exercise prescription. This method has been proven accurate in adults, but much less in known when applied to an adolescent population. The purpose of this study was to assess the accuracy of the RPE extrapolation as method for estimating VO2max in adolescents. Twenty-two healthy, asymptomatic adolescents performed a graded exercise test (GXT) to exhaustion. Heart rate and VO2 were recorded throughout the bout with RPE being queried every two minutes using the Borg (6-20) RPE scale. Individual regression lines were fitted for each subject using RPE and VO2 for RPE values up to 13,15, and 17. Theoretical maximal RPE values of 20 and 19 were entered into the equation to calculate an estimated VO2max. Repeated measures ANOVA with planned contrasts showed that all VO2max estimation methods significantly overpredicted measured VO2max (p < .001). Error analysis via Bland-Altman plots revealed large limits of agreement between the all methods, indicating large variability in error between estimated and measured VO2max. The results suggest that submaximal RPE values using the Borg scale cannot be used to predict VO2max in children due to the amount of error in the prediction equations. These inaccuracies could lead to potential under or over-prescription of exercise intensity and adverse effects on the person's health.