Gait speed is a measure of health and functioning. Physical and cognitive determinants of gait are amenable to interventions, but best practices remain unclear. We investigated the effects of a 12‐month physical and cognitive training (PTCT) on gait speed, dual‐task cost in gait speed, and executive functions (EFs) compared to physical training (PT) (ISRCTN52388040). Community‐dwelling older adults, who did not meet physical activity recommendations, were recruited (n=314). PT included supervised walking/balance (once weekly) and resistance/balance training (once weekly), home exercises (2‐3 times weekly) and moderate aerobic activity 150 minutes/week in bouts of >10 minutes. PTCT included the PT and computer training (CT) on EFs 15‐20 minutes, 3‐4 times weekly. The primary outcome was gait speed. Secondary outcomes were 6‐minute walking distance, dual‐task cost in gait speed, and EF (Stroop and Trail Making B‐A). The trial was completed by 93% of the participants (age 74.5 [SD3.8] years; 60% women). Mean adherence to supervised sessions was 59‐72% in PT and 62‐77% in PTCT. Home exercises and CT were performed on average 1.9 times/week. Weekly minutes spent in aerobic activities were 188 (median 169) in PT and 207 (median 180) in PTCT.

No significant interactions were observed for gait speed (PTCT‐PT, 0.02; 95%CI ‐0.03, 0.08), walking distance (‐3.8; ‐16.9, 9.3) or dual‐task cost (‐0.22; ‐1.74, 1.30). Stroop improvement was greater after PTCT than PT (‐6.9; ‐13.0, ‐0.8). Complementing physical training with EFs training is not essential for promotion of gait speed. For EF’s, complementing physical training with targeted cognitive training provides additional benefit.