The default runner is a man. It is free (and the game is free as well)
But take a look at upgrades that require to collect or buy coins (either way you expend effort or money as per freemium model). So if you want to choose a female runner you have to first collect 5000 coins (by running the man) or pay for it.
I see this as bad price discrimination – purely s a pricing practitioner as well as a dad. But …
What is your take?