The purpose of this study was to investigate the effect of moderate strength and endurance training on cognition evaluated by event-related potentials (ERP) in older people. Thirty-six adults, aged 60-85 years, were randomly divided into three groups: sedentary control (C), strength training (ST), and endurance training (ET). Participants performed functional fitness tests and ERP data were recorded before and after nine weeks of training. Training involved three sessions per week. Functional fitness test performance improved significantly in the ST and ET groups. The latencies of the N1, N2, and P2 components and the amplitudes of the N1P2, P2N2, and N2P3 components differed significantly between groups (p < 0.05). After training, the latencies of the P2 and N2 components at the Fz and Cz sites, decreased significantly, and the amplitudes of the N1P2, P2N2, and N2P3 components at the Fz site and the N1P2 and N2P3 components at the Cz site, increased significantly in the ST group compared with the ET group. After training, the latencies of N1, N2, and P2 components shortened significantly, and the amplitudes of the N1P2, P2N2, and N2P3 components increased significantly in the ST group compared with the C group. The latencies of the N2 and P2 components shortened significantly in the ET group compared with the C group, although the amplitudes of the ERP recordings did not differ significantly between groups. These data suggest that strength training might facilitate early sensory processing and cognitive functioning in older individuals.