Oxygen Uptake Kinetics and Time Limit at Maximal Aerobic Workload in Tethered Swimming

Danilo A Massini; Mário C Espada; Anderson G Macedo; Fernando J Santos; Eliane A Castro; Cátia C Ferreira; Ricardo A M Robalo; Amândio A P Dias; Tiago A F Almeida; Dalton M Pessôa Filho

doi:10.3390/metabo13070773

Oxygen Uptake Kinetics and Time Limit at Maximal Aerobic Workload in Tethered Swimming

Metabolites. 2023 Jun 21;13(7):773. doi: 10.3390/metabo13070773.

Authors

Danilo A Massini^{1

2}, Mário C Espada^{3

4

5}, Anderson G Macedo^{1

2}, Fernando J Santos^{3

4

6}, Eliane A Castro^{1

2

7}, Cátia C Ferreira^{3

8}, Ricardo A M Robalo^{3

6}, Amândio A P Dias⁹, Tiago A F Almeida^{1

2

5}, Dalton M Pessôa Filho^{1

2}

Affiliations

¹ Graduate Programme in Human Development and Technology, Institute of Biology, São Paulo State University (UNESP), Campus at Rio Claro, São Paulo 13506-900, Brazil.
² Physical Education Department, School of Sciences (FC), Universidade Estadual Paulista (UNESP), Campus at Bauru, São Paulo 17033-360, Brazil.
³ Instituto Politécnico de Setúbal, Escola Superior de Educação, 2914-504 Setúbal, Portugal.
⁴ Life Quality Research Centre (LQRC-CIEQV, Leiria), Complexo Andaluz, Apartado, 2040-413 Rio Maior, Portugal.
⁵ CIPER, Faculdade de Motricidade Humana, Universidade de Lisboa, 1499-002 Cruz Quebrada, Portugal.
⁶ Faculdade de Motricidade Humana, Universidade de Lisboa, 1499-002 Cruz Quebrada, Portugal.
⁷ LFE Research Group, Universidad Politécnica de Madrid (UPM), 28040 Madrid, Spain.
⁸ Research Group in Optimization of Training and Sport Performance (GOERD), Faculty of Sports Sciences, University of Extremadura, 10003 Caceres, Spain.
⁹ Egas Moniz Center for Interdisciplinary Research (CiiEM), Egas Moniz School of Health & Science, 2829-511 Caparica, Portugal.

Abstract

This study aimed to apply an incremental tethered swimming test (ITT) with workloads (WL) based on individual rates of front crawl mean tethered force (Fmean) for the identification of the upper boundary of heavy exercise (by means of respiratory compensation point, RCP), and therefore to describe oxygen uptake kinetics (VO₂k) and time limit (t_Lim) responses to WL corresponding to peak oxygen uptake (WLVO_2peak). Sixteen swimmers of both sexes (17.6 ± 3.8 years old, 175.8 ± 9.2 cm, and 68.5 ± 10.6 kg) performed the ITT until exhaustion, attached to a weight-bearing pulley-rope system for the measurements of gas exchange threshold (GET), RCP, and VO_2peak. The WL was increased by 5% from 30 to 70% of Fmean at every minute, with Fmean being measured by a load cell attached to the swimmers during an all-out 30 s front crawl bout. The pulmonary gas exchange was sampled breath by breath, and the mathematical description of VO₂k used a first-order exponential with time delay (TD) on the average of two rest-to-work transitions at WLVO_2peak. The mean VO_2peak approached 50.2 ± 6.2 mL·kg^-1·min^-1 and GET and RCP attained (respectively) 67.4 ± 7.3% and 87.4 ± 3.4% VO_2peak. The average t_Lim was 329.5 ± 63.6 s for both sexes, and all swimmers attained VO_2peak (100.4 ± 3.8%) when considering the primary response of VO₂ (A_1' = 91.8 ± 6.7%VO_2peak) associated with the VO₂ slow component (SC) of 10.7 ± 6.7% of end-exercise VO₂, with time constants of 24.4 ± 9.8 s for A_1' and 149.3 ± 29.1 s for SC. Negative correlations were observed for t_Lim to VO_2peak, WLVO_2peak, GET, RCP, and EEVO₂ (r = -0.55, -0.59, -0.58, -0.53, and -0.50). Thus, the VO₂k during tethered swimming at WLVO_2peak reproduced the physiological responses corresponding to a severe domain. The findings also demonstrated that t_Lim was inversely related to aerobic conditioning indexes and to the ability to adjust oxidative metabolism to match target VO₂ demand during exercise.

Keywords: conditioning assessment; exercise domain; oxygen uptake kinetics; tethered swimming.

Abstract

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