Distance unit (metric/km vs imperial/mi)

You can configure your preferred unit system (metric/km vs imperial/miles) in your profile. By default we guess your preference based on the country you are in in when creating your profile.

You can set your preference on the Edit Profile screen.

Event Settings will overrule your preference

The units which are configured for each event will overrule your personal setting. E.g. in your profile you will see all your data in your own preferred unit, but when looking at event progress status you will see that in the unit system configured by the organization. This is done so everyone participating in the challenge sees the same data.