Physics game is getting slow when i am adding revmob Ads

Physics
#1

Physics game is getting slow when i am adding revmob Ads.

I am using the below code for enable ads

RevMob.startSession(REVMOB_IDS) 

fullscreenRevMob = RevMob.showFullscreen(revmobListener, PLACEMENT_IDS)

fullscreenRevMob:show()