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The reliability of measuring gross efficiency during high intensity cycling exercise

Ebreo, Richard, Passfield, Louis, Hopker, James (2020) The reliability of measuring gross efficiency during high intensity cycling exercise. International Journal of Sports Physiology and Performance, 15 (1). pp. 126-132. ISSN 1555-0265. E-ISSN 1555-0273. (doi:10.1123/ijspp.2018-0949) (KAR id:75143)

Abstract

Purpose: To evaluate the reliability of calculating gross efficiency (GE) conventionally and using a back extrapolation (BE) method during high-intensity exercise (HIE).

Methods: A total of 12 trained participants completed 2 HIE bouts (P1 = 4 min at 80% maximal aerobic power [MAP]; P2 = 4 min at 100%MAP). GE was calculated conventionally in the last 3 minutes of submaximal (50%MAP) cycling bouts performed before and after HIE (Pre50%MAP and Post50%MAP). To calculate GE using BE (BGE), a linear regression of GE submaximal values post-HIE were back extrapolated to the end of the HIE bout.

Results: BGE was significantly correlated with Post50%MAP GE in P1 (r = .63; P = .01) and in P2 (r = .85; P = .002). Reliability data for P1 and P2 BGE demonstrate a mean coefficient of variation of 7.8% and 9.8% with limits of agreement of 4.3% and 4.5% in relative GE units, respectively. P2 BGE was significantly lower than P2 Post50%MAP GE (18.1% [1.6%] vs 20.3% [1.7%]; P = .01). Using a declining GE from the BE method, there was a 44% greater anaerobic contribution compared with assuming a constant GE during 4-minute HIE at 100%MAP.

Conclusion: HIE acutely reduced BGE at 100%MAP. A greater anaerobic contribution to exercise as well as excess postexercise oxygen consumption at 100%MAP may contribute to this decline in efficiency. The BE method may be a reliable and valid tool in both estimating GE during HIE and calculating aerobic and anaerobic contributions.

Item Type: Article
DOI/Identification number: 10.1123/ijspp.2018-0949
Subjects: R Medicine > RC Internal medicine > RC1200 Sports medicine
Divisions: Divisions > Division of Natural Sciences > Sport and Exercise Sciences
Depositing User: James Hopker
Date Deposited: 01 Jul 2019 09:51 UTC
Last Modified: 28 Jul 2022 22:10 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/75143 (The current URI for this page, for reference purposes)

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