Increased Ventilatory Efficiency in Supramaximal Compared to Graded Exercise in Athletes

• Published in: Research quarterly for exercise and sport pp. 1 - 8
• Main Authors: Barbosa, Juliana Peroni Abrahão, de Vargas, Wandriane, Del Rosso, Sebastián, Ravagnani, Christiane Coelho, Boullosa, Daniel A, de Tarso Muller, Paulo
• Format: Journal Article
• Language: English
• Published: United States 09-09-2024
• Subjects: exercise; ventilatory efficiency; Athlete; cardiopulmonary exercise testing
• ISSN: 0270-1367; 2168-3824; 2168-3824
• DOI: 10.1080/02701367.2024.2398577

: Supramaximal constant work rate tests (CWR) elicit intense hyperventilation, thus potentially up-shifting ventilation (⩒
)-to-carbon dioxide (CO
) responses when compared to graded exercise tests (GXT) in athletes. We predicted higher ventilatory efficiency on supramaximal CWR using a new method, challenging the classic orthodox interpretation of an increased ⩒
-⩒CO
as ventilatory inefficiency. This misinterpretation could make difficult to differentiate between physiological hyperventilation from heart disease conditions in athletes.
: On different days, a GXT and a CWR at 110% of the maximal velocity achieved in the GXT were performed. Twenty-seven athletes completed the two tests and were compared for usual (linear regression) and log-transformed new variables for ventilatory efficiency through paired
-Student statistics.
: The ⩒
-⩒CO
slope (31.4 ± 4.9
. 26.2 ± 3.4,
 < .001), ⩒
-⩒CO
intercept (7.2 ± 7.5
. 2.8 ± 4.2,
 < .007), ⩒
/⩒CO
nadir (33.0 ± 3.6
. 25.4 ± 2.2,
 < .001), ⩒CO
-log⩒
slope (10.8 ± 2.9
. 6.9 ± 2.2 L
logL
,
 < .001), and η⩒
(36.0 ± 12
. 22.8 ± 8.1%,
 < .001) values were all significantly higher in the CWR compared to the GXT. We registered a bi-modal nadir response for ⩒
⩒CO
on CWR for 22 out of 27 subjects for the first time. A weak association was observed between ⩒
/⩒CO
nadir (coefficient of determination ~ 27%) and time to exhaustion.
: The new method allows us to improve the quantification and interpretation of ventilatory efficiency in athletes, avoiding misinterpretation due to the up-shifting elicited by the usual ⩒
-⩒CO
slope and ⩒
/⩒CO
nadir indices, which may be confounded with ventilatory inefficiency. This study suggests that ventilatory changes underpin better ventilatory efficiency during CWR.