The reliability of back-extrapolation in estimating [Formula: see text] in different swimming performances at the severe-intensity domain

Danilo Alexandre Massini; Astor Reis Simionato; Tiago André Freire Almeida; Anderson Geremias Macedo; Mário Cunha Espada; Joana Filipa Reis; Francisco Besone Alves; Dalton Müller Pessôa Filho

doi:10.3389/fphys.2022.982638

The reliability of back-extrapolation in estimating ${\dot{V} O}_{2 p e a k}$ in different swimming performances at the severe-intensity domain

Front Physiol. 2022 Nov 3:13:982638. doi: 10.3389/fphys.2022.982638. eCollection 2022.

Authors

Danilo Alexandre Massini^{1

2}, Astor Reis Simionato¹, Tiago André Freire Almeida^{1

2

3}, Anderson Geremias Macedo^{1

2}, Mário Cunha Espada^{3

4

5}, Joana Filipa Reis^{3

6

7}, Francisco Besone Alves^{3

6}, Dalton Müller Pessôa Filho^{1

2}

Affiliations

¹ Postgraduate Program in Human Development and Technologies, São Paulo State University-UNESP, Rio Claro, São Paulo, Brazil.
² São Paulo State University-UNESP, Bauru, São Paulo, Brazil.
³ CIPER, Faculdade de Motricidade Humana, University de Lisboa, Lisboa, Portugal.
⁴ Polytechnic Institute of Setúbal (CIEF-ESE/IPS, CDP2T, ESTSetúbal/IPS), Setúbal, Portugal.
⁵ Life Quality Research Centre (CIEQV-Leiria), Rio Maior, Portugal.
⁶ Faculdade de Motricidade Humana, Universidade de Lisboa, Lisboa, Portugal.
⁷ Portugal Football School, Portuguese Football Federation, FPF, Cruz Quebrada, Portugal.

Abstract

The amount of anerobic energy released during exercise might modify the initial phase of oxygen recovery (fast-O_2debt) post-exercise. Therefore, the present study aimed to analyze the reliability of peak oxygen uptake $({\dot{V} O}_{2 p e a k})$ estimate by back-extrapolation $(B E - {\dot{V} O}_{2 p e a k})$ under different swimming conditions in the severe-intensity domain, verifying how the alterations of the ${\dot{V} O}_{2}$ recovery profile and anerobic energy demand might affect $B E - {\dot{V} O}_{2 p e a k}$ values. Twenty swimmers (16.7 ± 2.4 years, 173.5 ± 10.2 cm, and 66.4 ± 10.6 kg) performed an incremental intermittent step protocol (IIST: 6 × 250 plus 1 × 200 m, IIST_v200m) for the assessment of ${\dot{V} O}_{2 p e a k}$ . The ${\dot{V} O}_{2}$ off-kinetics used a bi-exponential model to discriminate primary amplitude, time delay, and time constant (A_1off, TD_1off, and τ_off) for assessment of fast-O_2debt post IIST_v200m, 200-m single-trial (v200 m), and rest-to-work transition at 90% delta (v90%Δ) tests. The linear regression estimated $B E - {\dot{V} O}_{2 p e a k}$ and the rate of ${\dot{V} O}_{2}$ recovery (BE-slope) post each swimming performance. The ANOVA (Sidak as post hoc) compared ${\dot{V} O}_{2 p e a k}$ to the estimates of $B E - {\dot{V} O}_{2 p e a k}$ in v200 m, IIST_v200 m, and v90%Δ, and the coefficient of dispersion (R²) analyzed the association between tests. The values of ${\dot{V} O}_{2 p e a k}$ during IIST did not differ from $B E - {\dot{V} O}_{2 p e a k}$ in v200 m, IIST_v200 m, and v90%Δ (55.7 ± 7.1 vs. 53.7 ± 8.2 vs. 56.3 ± 8.2 vs. 54.1 ± 9.1 ml kg^-1 min^-1, p > 0.05, respectively). However, the ${\dot{V} O}_{2 p e a k}$ variance is moderately explained by $B E - {\dot{V} O}_{2 p e a k}$ only in IIST_v200 m and v90%Δ (R_Adj ² = 0.44 and R_Adj ² = 0.43, p < 0.01). The TD_1off and τ_off responses post IIST_v200 m were considerably lower than those in both v200 m (6.1 ± 3.8 and 33.0 ± 9.5 s vs. 10.9 ± 3.5 and 47.7 ± 7.9 s; p < 0.05) and v90%Δ ( 10.1 ± 3.8 and 44.3 ± 6.3 s, p < 0.05). The BE-slope post IIST_v200m was faster than in v200 m and v90%Δ (-47.9 ± 14.6 vs. -33.0 ± 10.4 vs. -33.6 ± 13.8 ml kg^-1, p < 0.01), and the total anerobic (Anaer_Total) demand was lower in IIST_v200 m (37.4 ± 9.4 ml kg^-1) than in 200 m and 90%Δ (51.4 ± 9.4 and 46.2 ± 7.7 ml kg^-1, p < 0.01). Finally, the τ_1off was related to Anaer_Total in IIST_v200m, v200 m, and v90%Δ (r = 0.64, r = 0.61, and r = 0.64, p < 0.01). The initial phase of the ${\dot{V} O}_{2}$ recovery profile provided different (although reliable) conditions for the estimate of ${\dot{V} O}_{2 p e a k}$ with BE procedures, which accounted for the moderate effect of anerobic release on ${\dot{V} O}_{2}$ off-kinetics, but compromised exceptionally the ${\dot{V} O}_{2 p e a k}$ estimate in the 200-m single trial.

Keywords: back-extrapolation; oxygen uptake kinetics; oxygen uptake recovery; peak oxygen uptake; swimming.