Spinning the photo disc of a gym now awards you the gyms corresponding badge. It is then possible to increase your badge level by executing some specific actions, such as feeding the Pokemon of your team with berries, defending your gym or attacking an opponent gym. But, as there is no experience amount displayed on the badge, it's hard to determine how many points are needed to level up a badge, or how many points are awarded for executing a specific action.
How many points (or actions) are needed to get a new specific badge level? Do some actions award you with more points than the others?
Best Answer
We do know we'll be able to level up Gym Badges by performing the following activities:
(thanks to the Silph Road sub-Reddit user for clarifying some of these numbers):
By performing the above activities, whether you are passive and prefer to increase Motivation as you pass a Gym, or are actively battling and holding creatures there, you can level up your Badge over time.
Badge XP needed for a gym medal is:
(So Silver is 3500 XP more needed after getting the Bronze gym badge)
Edit on 9 July:
Found this webpage that also gives a lot of information about XP on Gym systems: Gym Badge Experience