Détermination non invasive de la capacité maximale d'extraction tissulaire de l'oxygène et niveaux d'aptitude physique d'adolescents sportifs

Abstract: Objective: To evaluate non-invasively the patterns of the Fick equation components during an incremental ergocycle test. Methods: Simultaneous measurements of gas exchanges and cardiac output () — thoracic impedance device Physioflow Manatec — supply the Fick equation''s variables: . Their dynamics are studied at 1st and 2nd ventilatory threshold (SV1, SV2) and at PMT (Max Tolerated Power) in 41 active adolescent boys; 25 of them are highly trained (TP) and 16 occasionally (P). There is no anthropometric difference between the 2 groups. Results: 1) Individual slopes "a" of regression against are negative: the higher the "a" value the lower , PMT, maximal tissular O2 extraction , and… the adolescents'' performance; 2) as early as at SV1, in TP is always higher than in P; whereas , FC and stroke volume (VES) have similar values in both groups at SV1, SV2 and PMT; 3) in all subjects, TP and P, VES max and were reached at the level of SV2. Conclusion: Non invasive and simultaneaous and mesurements during incremental test lead to Fick equation adjustements, "a" slope and difference contributing thus to interesting indications of subjects'' fitness. [Copyright &y& Elsevier]