Experimental procedure: (A) Experiment 1. Participants completed 5 trials of each of the following tasks; walking alone (ST-walking), counting while standing (Counting), and walking while counting (DT-walking). Each trial consisted of a 30-second task period and alternated with rest periods in a pseudo-random order. (B) Experiment 2; one ABCD cycle. This cycle was repeated 6 times giving a total paradigm length of 12 minutes. The top row indicates when participants engaged in the counting task, the second row indicates when participants were moving their feet and the third row indicates the interaction between the 2 (ie, blocks when the 2 tasks were performed simultaneously). ST, single task; DT, dual task.