Challenges are competitions to challenge yourself and your friends. Compete against others to see who can top the leaderboard. You are able to join any challenge. To participate you will need to automatically track your data using a wearable device like Fitbit or an app like Strava.
To join a challenge you will need to do the following:
Click on "Challenges" on the menu
Click on "Join challenge" on the challenge you would like to join
Once you have joined a challenge you will be taken to the challenge details where you will see a description of the challenge, your current score and the challenge leaderboard
To leave a challenge you will need to do the following:
Select "Challenges" from the menu
Select the challenge you would like to leave
Select the three dots on the top right hand side of the challenge screen and select leave challenge