Underestimation of Economy from Incremental Tests: Implications for Practitioners

Mark Tabrett, C. C. T. Clark, Stephen C How, Steve Draper

Research output: Contribution to journalJournal Article

Abstract

Purpose: Current practices for estimating exercise economy using an extrapolation of sub-gas exchange threshold (GET), and to a lesser degree supra-GET, data will likely result an underestimation of actual economy, however, this is yet to be empirically demonstrated. Despite contentions, these protocols remain in widespread use. Therefore, the aim of the present study was to investigate whether estimation of exercise economy from moderate only, and moderate and heavy intensity exercise underestimates actual oxygen cost. Summary of Facts and Results: Twelve recreationally active males (mean ± SD; age 29 ± 9y, height 1.81 ± 0.07 m, mass 81.4 ± 10 kg) volunteered for this study. Following a maximal ramp test to determine the V̇O2peak, peak power (Wpeak), V̇O2 and power output at GET, participants completed a sub-GET only, a sub/supra-GET (both five-stage incremental tests), and a fixed WR protocol (10 min duration at 75% Δ). Economy was determined by extrapolation of sub- and sub/supra-GET V̇O2 and directly measured V̇O2 at 75% Δ. Within-subjects ANOVA was performed to identify differences in economy between sub-GET only, sub/supra-GET, and fixed WR protocols. Significant effects between the predicted values compared to the measured value were investigated post hoc using Bonferroni corrected paired t-tests. There was a significant effect of protocol on V̇O2 and economy (P <0.001, η2p = 0.645), where both methods of estimation underestimated the actual oxygen cost. In addition, estimation-using sub-GET data was significantly lower than sub/supra-GET (P <0.05). Conclusion: The large error obtained by extrapolating sub-GET exercise intensities for the purpose of estimating exercise economy needs to be acknowledged, as does the concomitant, albeit reduced, error that remains when incorporating supra-GET data. Exercise scientists and practitioners should adopt more appropriate testing protocols such as serial assessments, up-to and including race pace, to accurately assess economy.
Original languageEnglish
JournalScience and Sports
Early online date20 Jun 2019
DOIs
Publication statusE-pub ahead of print - 20 Jun 2019

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Gases
Exercise
Oxygen
Costs and Cost Analysis
Architectural Accessibility
Analysis of Variance

Keywords

  • Exercise
  • Economy
  • Prediction
  • O2 Cost
  • Measurement

Cite this

@article{2777fd3316824148bbfb6eec2bdda25c,
title = "Underestimation of Economy from Incremental Tests: Implications for Practitioners",
abstract = "Purpose: Current practices for estimating exercise economy using an extrapolation of sub-gas exchange threshold (GET), and to a lesser degree supra-GET, data will likely result an underestimation of actual economy, however, this is yet to be empirically demonstrated. Despite contentions, these protocols remain in widespread use. Therefore, the aim of the present study was to investigate whether estimation of exercise economy from moderate only, and moderate and heavy intensity exercise underestimates actual oxygen cost. Summary of Facts and Results: Twelve recreationally active males (mean ± SD; age 29 ± 9y, height 1.81 ± 0.07 m, mass 81.4 ± 10 kg) volunteered for this study. Following a maximal ramp test to determine the V̇O2peak, peak power (Wpeak), V̇O2 and power output at GET, participants completed a sub-GET only, a sub/supra-GET (both five-stage incremental tests), and a fixed WR protocol (10 min duration at 75{\%} Δ). Economy was determined by extrapolation of sub- and sub/supra-GET V̇O2 and directly measured V̇O2 at 75{\%} Δ. Within-subjects ANOVA was performed to identify differences in economy between sub-GET only, sub/supra-GET, and fixed WR protocols. Significant effects between the predicted values compared to the measured value were investigated post hoc using Bonferroni corrected paired t-tests. There was a significant effect of protocol on V̇O2 and economy (P <0.001, η2p = 0.645), where both methods of estimation underestimated the actual oxygen cost. In addition, estimation-using sub-GET data was significantly lower than sub/supra-GET (P <0.05). Conclusion: The large error obtained by extrapolating sub-GET exercise intensities for the purpose of estimating exercise economy needs to be acknowledged, as does the concomitant, albeit reduced, error that remains when incorporating supra-GET data. Exercise scientists and practitioners should adopt more appropriate testing protocols such as serial assessments, up-to and including race pace, to accurately assess economy.",
keywords = "Exercise, Economy, Prediction, O2 Cost, Measurement",
author = "Mark Tabrett and Clark, {C. C. T.} and How, {Stephen C} and Steve Draper",
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doi = "10.1016/j.scispo.2019.02.008",
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Underestimation of Economy from Incremental Tests: Implications for Practitioners. / Tabrett, Mark; Clark, C. C. T.; How, Stephen C; Draper, Steve.

In: Science and Sports, 20.06.2019.

Research output: Contribution to journalJournal Article

TY - JOUR

T1 - Underestimation of Economy from Incremental Tests: Implications for Practitioners

AU - Tabrett, Mark

AU - Clark, C. C. T.

AU - How, Stephen C

AU - Draper, Steve

PY - 2019/6/20

Y1 - 2019/6/20

N2 - Purpose: Current practices for estimating exercise economy using an extrapolation of sub-gas exchange threshold (GET), and to a lesser degree supra-GET, data will likely result an underestimation of actual economy, however, this is yet to be empirically demonstrated. Despite contentions, these protocols remain in widespread use. Therefore, the aim of the present study was to investigate whether estimation of exercise economy from moderate only, and moderate and heavy intensity exercise underestimates actual oxygen cost. Summary of Facts and Results: Twelve recreationally active males (mean ± SD; age 29 ± 9y, height 1.81 ± 0.07 m, mass 81.4 ± 10 kg) volunteered for this study. Following a maximal ramp test to determine the V̇O2peak, peak power (Wpeak), V̇O2 and power output at GET, participants completed a sub-GET only, a sub/supra-GET (both five-stage incremental tests), and a fixed WR protocol (10 min duration at 75% Δ). Economy was determined by extrapolation of sub- and sub/supra-GET V̇O2 and directly measured V̇O2 at 75% Δ. Within-subjects ANOVA was performed to identify differences in economy between sub-GET only, sub/supra-GET, and fixed WR protocols. Significant effects between the predicted values compared to the measured value were investigated post hoc using Bonferroni corrected paired t-tests. There was a significant effect of protocol on V̇O2 and economy (P <0.001, η2p = 0.645), where both methods of estimation underestimated the actual oxygen cost. In addition, estimation-using sub-GET data was significantly lower than sub/supra-GET (P <0.05). Conclusion: The large error obtained by extrapolating sub-GET exercise intensities for the purpose of estimating exercise economy needs to be acknowledged, as does the concomitant, albeit reduced, error that remains when incorporating supra-GET data. Exercise scientists and practitioners should adopt more appropriate testing protocols such as serial assessments, up-to and including race pace, to accurately assess economy.

AB - Purpose: Current practices for estimating exercise economy using an extrapolation of sub-gas exchange threshold (GET), and to a lesser degree supra-GET, data will likely result an underestimation of actual economy, however, this is yet to be empirically demonstrated. Despite contentions, these protocols remain in widespread use. Therefore, the aim of the present study was to investigate whether estimation of exercise economy from moderate only, and moderate and heavy intensity exercise underestimates actual oxygen cost. Summary of Facts and Results: Twelve recreationally active males (mean ± SD; age 29 ± 9y, height 1.81 ± 0.07 m, mass 81.4 ± 10 kg) volunteered for this study. Following a maximal ramp test to determine the V̇O2peak, peak power (Wpeak), V̇O2 and power output at GET, participants completed a sub-GET only, a sub/supra-GET (both five-stage incremental tests), and a fixed WR protocol (10 min duration at 75% Δ). Economy was determined by extrapolation of sub- and sub/supra-GET V̇O2 and directly measured V̇O2 at 75% Δ. Within-subjects ANOVA was performed to identify differences in economy between sub-GET only, sub/supra-GET, and fixed WR protocols. Significant effects between the predicted values compared to the measured value were investigated post hoc using Bonferroni corrected paired t-tests. There was a significant effect of protocol on V̇O2 and economy (P <0.001, η2p = 0.645), where both methods of estimation underestimated the actual oxygen cost. In addition, estimation-using sub-GET data was significantly lower than sub/supra-GET (P <0.05). Conclusion: The large error obtained by extrapolating sub-GET exercise intensities for the purpose of estimating exercise economy needs to be acknowledged, as does the concomitant, albeit reduced, error that remains when incorporating supra-GET data. Exercise scientists and practitioners should adopt more appropriate testing protocols such as serial assessments, up-to and including race pace, to accurately assess economy.

KW - Exercise

KW - Economy

KW - Prediction

KW - O2 Cost

KW - Measurement

U2 - 10.1016/j.scispo.2019.02.008

DO - 10.1016/j.scispo.2019.02.008

M3 - Journal Article

JO - Science and Sports

JF - Science and Sports

SN - 0765-1597

ER -