Centenarians are an outstanding model of successful aging, with genetics and healthy lifestyle certainly being key factors responsible for their longevity. Exercise capacity has been identified to play an important role in healthy aging, but a comprehensive assessment of the limitations to maximal exercise in this population is lacking. Following, health histories, lung function, and anthropometric measures, eight female centenarians (98-102 years old) and eight young females (18-22 years old) performed a series of graded maximal exercise tests on a cycle ergometer that facilitated absolute and relative work rate comparisons. Centenarians revealed a dramatically attenuated lung function, as measured by spirometry (forced expiratory volume in 1 s (FEV/forced vital capacity (FVC), 55 ± 10%) compared to the young (FEV/FVC, 77 ± 5%). During exercise, although the centenarians relied heavily on respiratory rate which yielded ∼50% higher dead space/tidal volume, minute ventilation was similar to that of the young at all but maximal exercise, and alveolar PO was maintained in both groups. In contrast, peak WR and VO were significantly reduced in the centenarians (33 ± 4 vs 179 ± 24 W; 7.5 ± 1.2 vs 39.6 ± 3.5 ml min kg). Arterial PO of the centenarians fell steadily from the normal range of both groups to yield a large A-a gradient (57 ± 6 mmHg). Metabolic cost of a given absolute work rate was consistently lower, ∼46% less than the young at maximal effort. Centenarians have significant limitations to gas exchange across the lungs during exercise, but this limited oxygen transport is tempered by improved skeletal muscle mechanical efficiency that may play a vital role in maintaining physical function and therefore longevity in this population. [ABSTRACT FROM AUTHOR]