Resumen: To objectively assess physical activity levels and sedentary behavior in a cohort of Spanish centenarians and their nonagenarian peers. Physical activity and sedentary behavior patterns were objectively measured by an ActiGraph GT3X accelerometer in centenarians (n = 18; 83% women; 100.8 ± 0.8 [100–103] years) and nonagenarians (n = 11; 91% women; 93.3 ± 2.5 [90–98] years). Centenarians showed less counts per minute (17.6 ± 7.1 vs. 46.1 ± 23.7, p = .003, d = 1.851) and steps per day (455 ± 237 vs. 1,249 ± 776, p = .007, d = 1.587) than nonagenarians. The daily number of sedentary breaks was also lower in the former (5.0 ± 1.5 vs. 6.7 ± 2.0, p = .019, d = 0.971). When observing time distribution, the most active day period in both groups was the morning, with a peak between 10:00 and 11:59. This data suggest that the decline in physical activity levels continues to worsen until the end of the human lifespan. Idioma: Inglés DOI: 10.1123/japa.2018-0122 Año: 2019 Publicado en: JOURNAL OF AGING AND PHYSICAL ACTIVITY 27, 6 (2019), 899-905 ISSN: 1063-8652 Factor impacto JCR: 1.763 (2019) Categ. JCR: GERONTOLOGY rank: 18 / 36 = 0.5 (2019) - Q2 - T2 Categ. JCR: SPORT SCIENCES rank: 52 / 85 = 0.612 (2019) - Q3 - T2 Categ. JCR: GERIATRICS & GERONTOLOGY rank: 37 / 51 = 0.725 (2019) - Q3 - T3 Factor impacto SCIMAGO: 0.706 - Rehabilitation (Q1) - Gerontology (Q2) - Sports Science (Q2) - Geriatrics and Gerontology (Q2) - Physical Therapy, Sports Therapy and Rehabilitation (Q2)