Zoë is reading book I had as a junior. Orienteering by John Disley 2nd edition 1978

First page Chapter 11 \"Fitness Training for Orienteering\"

Actually, running is a very simple activity and the technique of moving from place to place on two legs is easily learnt. As long as it is appreciated that the left leg is not used twice in succession then there isn\'t much more to learn and most of us are reasonably efficient in this skill

So if you see Zoë using the right leg twice in succession, you know why!!