You can permanently close your account by following the process below :
Go to More > Settings > Pictures, password, infos > Delete your account and activities permanently at the bottom right of this page
Go to Dashboard > ⚙ (on the left of your screen) > Edit my information > Edit > Delete your account and activities permanently (at the bottom right of this page)
The total deletion of your account may take several days.By deleting your account, you will permanently delete all the activities that have been synched with your Sport Heroes account. You will also loose access to all the experiences linked to your Sport heroes account: What is my Sport Heroes account for?. This action is irreversible.