Background:As there is no gold-standard methodology to classify older people in relation to physical activity (PA) and sedentary behavior (SB), this paper aimed to propose a classification combining PA and SB.Methods:Within a broader study, 433 subjects, aged 55 years and older (57% females) from Madrid and Majorca, were evaluated for PA and SB by means of validated questionnaires. Physical fitness was analyzed objectively using the EXERNET test battery. Cluster analyses were used to establish behavioral patterns, combining PA and SB.Results:Males spent more time doing regular PA but less time walking and working at home than females (P < .001). Comparing the groups (inactive and high sedentary, inactive and low sedentary, active and high sedentary, and active and low sedentary), the worst aerobic endurance (P < .001) and lower body strength (P < .05) were obtained in males from both inactive groups. Agility was highest in the active and low sedentary group (P < .05). No significant differences were observed in females.Conclusions:The proposed classification is valid, as it classifies subjects according to their PA and SB, and outcomes are related to objectively measured fitness. It could facilitate the work of public health authorities, researchers, and physicians.