Exercise has been shown to increase mood and has been used successfully to lower rates of depression and anxiety. Being active also develops the motor skills of children and protects against cognitive decline in the elderly. Yet for the first time in history more of the worlds population live in urban than non-urban environments. Through urban design and transport policy, governments influence the way we navigate through our neighbourhoods and towns. To improve our well-being, policies could support more green space to encourage exercise and play and prioritise cycling and walking over car use.