Muscle Oxidative Capacity in Vivo Is Associated With Physiological Parameters in Trained Rowers

ABSTRACT

Purpose: The muscle oxygen uptake ($m\dot{V}{O}_2$) kinetics following exercise, measured by near-infrared spectroscopy, has been used as a functional evaluation of muscle oxidative metabolism. This study aimed to determine the $m\dot{V}{O}_2$ off-kinetics and verify the relationship of the recovery rate of $m\dot{V}{O}_2$ (k) with time-trial performance and different aerobic parameters in trained rowers. Methods: Eleven male rowers (age: 20 ± 3 years; $\dot{\mathrm{V}}{\mathrm{O}}_2\mathrm{m}\mathrm{a}\mathrm{x}$: 4.28 ± 0.35 L·min⁻¹) used a rowing ergometer to perform (I) an incremental test to determine the maximal oxygen uptake ($\dot{\mathrm{V}}{\mathrm{O}}_2\mathrm{m}\mathrm{a}\mathrm{x}$) and peak power output (P_peak); (II) several visits to determine maximal lactate steady state (MLSS); and (III) a 2000-m rowing ergometer performance test. Also, one test to determine $m\dot{V}{O}_2$ off-kinetics of the vastus lateralis muscle using a repeated arterial occlusions protocol. Results: The $m\dot{V}{O}_2$ generated a good monoexponential fit (R² = 0.960 ± 0.030; SEE = 0.041 ± 0.018%.s⁻¹). The k of $m\dot{V}{O}_2$ (2.06 ± 0.58 min⁻¹) was associated with relative $\dot{\mathrm{V}}{\mathrm{O}}_2\mathrm{m}\mathrm{a}\mathrm{x}$ (r = 0.79), power output at MLSS (r = 0.76), and P_peak (r = 0.83); however, it was not related with 2000-m rowing performance (r = −0.38 to 0.52; p > .152). Conclusion: These findings suggest that although not associated with rowing performance, the $m\dot{V}{O}_2$ off-kinetics determined after a submaximal isometric knee extension may be a practical and less-exhaustive approach than invasive responses and incremental tests to assess the muscle oxidative metabolism during a training program.

Highlights

• 1) The present study showed that the NIRS-derived $\mathrm{m}\dot{\mathrm{V}}{\mathrm{O}}_2$ off-kinetics from the vastus lateralis can be used as a functional tool of skeletal muscle oxidative metabolism in rowers.

• 2) The results demonstrated that the recovery rate of $\mathrm{m}\dot{\mathrm{V}}{\mathrm{O}}_2$ was well correlated with important aerobic parameters such as $\dot{\mathrm{V}}{\mathrm{O}}_2\mathrm{m}\mathrm{a}\mathrm{x}$, maximal lactate steady state, and peak power output during an incremental test.

KEYWORDS:

• Muscle oxygen extraction
• NIRS
• physiological markers
• sports performance

Acknowledgments

The authors would like to acknowledge Clube Náutico Francisco Martinelii, Clube de Regatas Aldo Luz and Clube Náutico Riachuelo for their contribution. The authors would also like to recognize the following coaches for their contribution to the project: Thiago Almeida, Marco Moreira Martins, and Thainá Korpalsky.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author contributions

LTP, RAA, FKB, PCNS, RDL and TT conceived and designed research; LTP, FKB and TT performed experiments; LTP, FKB and TT analyzed data; LTP, RAA, FKB, PCNS and TT interpreted results of experiments; LTP drafted manuscript; LTP, RAA, FKB, PCNS, RDL and TT edited, revised, and approved the final version of the manuscript.

Additional information

Funding

This work was supported by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (CAPES) – Finance code 001. Dr Paulo Cesar do Nascimento Salvador also acknowledges the support by grants from Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) – Brasil (154191/2018-3).