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Energy Expenditure Equation Choice: Effects on Cycling Efficiency and its Reliability

Bossi, Arthur H.; Timmerman, Wouter P.; Hopker, James G.

Authors

Wouter P. Timmerman

James G. Hopker



Abstract

Purpose: There are several published equations to calculate energy expenditure (EE) from gas exchanges. The authors assessed whether using different EE equations would affect gross efficiency (GE) estimates and their reliability. Methods: Eleven male and 3 female cyclists (age 33 [10] y; height: 178 [11] cm; body mass: 76.0 [15.1] kg; maximal oxygen uptake: 51.4 [5.1] mL·kg−1·min−1; peak power output: 4.69 [0.45] W·kg−1) completed 5 visits to the laboratory on separate occasions. In the first visit, participants completed a maximal ramp test to characterize their physiological profile. In visits 2 to 5, participants performed 4 identical submaximal exercise trials to assess GE and its reliability. Each trial included three 7-minute bouts at 60%, 70%, and 80% of the gas exchange threshold. EE was calculated with 4 equations by Péronnet and Massicotte, Lusk, Brouwer, and Garby and Astrup. Results: All 4 EE equations produced GE estimates that differed from each other (all P < .001). Reliability parameters were only affected when the typical error was expressed in absolute GE units, suggesting a negligible effect—related to the magnitude of GE produced by each EE equation. The mean coefficient of variation for GE across different exercise intensities and calculation methods was 4.2%. Conclusions: Although changing the EE equation does not affect GE reliability, exercise scientists and coaches should be aware that different EE equations produce different GE estimates. Researchers are advised to share their raw data to allow for GE recalculation, enabling comparison between previous and future studies.

Journal Article Type Article
Publication Date Feb 1, 2020
Deposit Date Aug 16, 2022
Journal International Journal of Sports Physiology and Performance
Print ISSN 1555-0265
Electronic ISSN 1555-0273
Publisher Human Kinetics
Peer Reviewed Peer Reviewed
Volume 15
Issue 2
Pages 288-291
DOI https://doi.org/10.1123/ijspp.2018-0818
Keywords gross efficiency; cycling economy; metabolic rate; respiratory exchange ratio; measurement error
Public URL http://researchrepository.napier.ac.uk/Output/2896928