ORIGINAL ARTICLE  EXERCISE PHYSIOLOGY AND BIOMECHANICS 

The Journal of Sports Medicine and Physical Fitness 2021 April;61(4):519-26

DOI: 10.23736/S0022-4707.20.11326-4

Copyright © 2020 EDIZIONI MINERVA MEDICA

language: English

Backward extrapolation technique: analysis of different criteria after supramaximal exercise in cycling

Gabriel LUCHES-PEREIRA ¹ ✉, Carlos A. KALVA-FILHO ², Ricardo A. BARBIERI ³, Vitor L. DE ANDRADE ⁴, Danilo R. BERTUCCI ⁵, Ronaldo B. GOBBI ⁴, Marcelo PAPOTI ^{1, 5, 6}

¹ Postgraduate Program in Physical Education and Sport, School of Physical Education and Sport of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil; ² Faculty of Sciences, Sao Paulo State University (UNESP), Bauru, Brazil; ³ Centro Universitário Estácio de Ribeirão Preto, Ribeirão Preto, São Paulo, Brazil; ⁴ Centro Universitário UNIFAFIBE, Bebedouro, Brazil; ⁵ Institute of Biosciences and Postgraduate Program in Movement Sciences, Sao Paulo State University (UNESP), Rio Claro, Brazil; ⁶ School of Physical Education and Sports of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil

BACKGROUND: Backward extrapolation technique (BE) was used to estimate V̇O2 from postexercise measuring, eliminating oronasal mask (OM) during the efforts. Despite its advantage, literature presents discrepancy in applied methods. Thus, the first aim of this study was to compare different mathematical criteria to estimate values of V̇O2 during a supramaximal effort (V̇O2PEAK), while the second aim was to verify the effects of OM on cycling performance.
METHODS: Twenty-four male cyclists (35±6 years, 81.3±8.9 kg, 180±6 cm) performed three days of tests, with at least 24 h of interval between each test. Firstly, a graded exercise test was applied to determine V̇O2max and your correspondent intensity (MAP). The second and the third day were destined to supramaximal efforts at 120% of MAP, performed with (Supramask) and without (Suprabe) oronasal mask (OM) in a randomized order. After Suprabe, OM was coupled, and BE was applied. Sixty-six values of V̇O2 were obtained based on a linear regression fitting.
RESULTS: V̇O2peak can be estimated using different curve lengths. However, only curves between 20 and 60 s with extrapolation to 3 s or lesser shows at least one consistent criterion. The 60 s curve extrapoled to -3 s was the most accurate criteria (P=0.723; ES=-0.055; r=0.824; Bias=-0.36 and LoA=7.72 mL.kg.min^-1). Performance was not impaired with OM and was similar in both condition (P=0.84, ES=0.04).
CONCLUSIONS: We conclude that it was possible to accurately estimate V̇O2 values of a supramaximal effort without any respiratory apparatus with a time-efficient analysis. Therefore, we recommended the use of a 60 seconds V̇O2 curve analysis with a negative extrapolation for 3 seconds.

KEY WORDS: Exercise test; Exercise tolerance; Oxygen consumption; Cardiorespiratory fitness; Regression analysis