Resumen de Effects of Aging and Training Status on Ventilatory Response During Incremental Cycling Exercise
Mauro Lenti, Giuseppe De Vito, Alessandro Scotto Di Palumbo, Paola Sbriccoli, Filippo M. Quattrini, Massimo Sacchetti
The aim of this study was to examine the effect of aging and training status on ventilatory response during incremental cycling exercise. Eight young (24 ± 5 years) and 8 older (64 ± 3 years) competitive cyclists together with 8 young (27 ± 4 years) and 8 older (63 ± 2 years) untrained individuals underwent a continuous incremental cycling test to exhaustion to determine ventilatory threshold (VT), respiratory compensation point (RCP), and maximal oxygen uptake ([latin capital V with dot above]o2max). In addition, the isocapnic buffering (IB) phase was calculated together with the hypocapnic hyperventilation. Ventilatory threshold occurred at similar relative exercise intensities in all groups, whereas RCP was recorded at higher intensities in young and older cyclists compared to the untrained subjects. The IB phase, reported as the difference between VT and RCP and expressed either in absolute (ml·min-1·kg-1 [latin capital V with dot above]o2) or in relative terms, was greater (p < 0.01) in both young and older trained cyclists than in untrained subjects, who were also characterized by a lower exercise capacity. Isocapnic buffering was particularly small in the older untrained volunteers. Although young untrained and older trained subjects had a similar level of [latin capital V with dot above]o2max, older athletes exhibited a larger IB. In addition, a higher absolute but similar relative IB was observed in young vs. older cyclists, despite a higher [latin capital V with dot above]o2max in the former. In conclusion, the present study shows that aging is associated with a reduction of the IB phase recorded during an incremental exercise test. Moreover, endurance training induces adaptations that result in an enlargement of the IB phase independent of age. This information can be used for the characterization and monitoring of the physiological adaptations induced by endurance training.
