How do duels in the Arena work?

EXPLANATION

Stake categories include Activity Points, steps, cycling kilometres or push-ups, each shown with your own daily average as a guide.
There are two modes: a direct challenge to a specific person, or an open duel against anyone in the club.
A posted duel can be accepted by others in your league. Once accepted, it runs for 24 hours, after which whoever collected more wins.
You see your current and past duels, plus your league stats, directly in the Arena.

STEP BY STEP

Open a club and tap Arena.
Tap the plus icon top right.
Choose a mode: Direct challenge or Open duel.
Select a stake category, for example steps.
Post the duel and wait for it to be accepted, or accept an open duel from another member.

In the Arena you challenge other members of your club 1 against 1. You choose a category like Activity Points or Steps, and whoever has collected more after 24 hours wins.