International audience Lifespan trends progression has worldwide practical implications as it may affect the sustainability of modern societies. We aimed to describe the secular lifespan trends of populations with a propensity to live longer—Olympians and super-centenarians—under two hypotheses: an ongoing lifespan extension versus a biologic " probabilistic barrier " limiting further progression. In a study of lifespan densities (total number of life durations per birth date), we analyzed 19,012 Olympians and 1,205 supercentenarians deceased between 1900 and 2013. Among most Olympians, we observed a trend toward increased life duration. This trend, however, decelerates at advanced ages leveling off with the upper values with a perennial gap between Olympians and supercentenarians during the whole observation period. Similar tendencies are observed among supercentenarians, and over the last years, a plateau attests to a stable longevity pattern among the longest-lived humans. The common trends between Olympians and supercentenarians indicate similar mortality pressures over both populations that increase with age, scenario better explained by a biologic " barrier " forecast.