Background: Attention is considered a central control mechanism in cognitive processing systems. Attention deficits contribute to the symptomatic profile of Alzheimer's disease (AD). Physical exercise and cognitive reserve, could delay cognitive impairment and constitute a protective factor against clinical manifestations of AD. Aim: To relate the functionality of the attentional networks with physical activity and cognitive reserve. Material and methods: Three groups of 20 older adults each (control, physical activity and with osteoarthritis) were studied. The Functional capacity assessment test, Cognitive Reserve Questionnaire and the Attention Networks Test - for Interactions and Vigilance or ANTI-V were applied to participants. Results: Significant differences were observed in the response times of the alert, orientation and executive network, and the percentage of success in the network orientation and executive network. No differences between groups were observed for the different indicators of vigilance. Conclusions: These results confirm the benefits of physical exercise as a protective factor for attentional functioning.Background: Attention is considered a central control mechanism in cognitive processing systems. Attention deficits contribute to the symptomatic profile of Alzheimer's disease (AD). Physical exercise and cognitive reserve, could delay cognitive impairment and constitute a protective factor against clinical manifestations of AD. Aim: To relate the functionality of the attentional networks with physical activity and cognitive reserve. Material and methods: Three groups of 20 older adults each (control, physical activity and with osteoarthritis) were studied. The Functional capacity assessment test, Cognitive Reserve Questionnaire and the Attention Networks Test - for Interactions and Vigilance or ANTI-V were applied to participants. Results: Significant differences were observed in the response times of the alert, orientation and executive network, and the percentage of success in the network orientation and executive network. No differences between groups were observed for the different indicators of vigilance. Conclusions: These results confirm the benefits of physical exercise as a protective factor for attentional functioning.