Gyms have a problem with people filming their workouts?
Jesus, if that's true then there can be only two general reasons.
1) The owner of the gym in question is a wanker for whom having-a-problem is the default setting in any situation.
or
2) The gym belongs to a chain like David Lloyd/Fitness First/JJB, and the manager is an empty-shell ambitious fart who can't wipe his/her arse without making a phone call first.
People LOVE waving their hands in camera lenses, protesting about filming, largely because they've seen people do so on television.
The people who do so are rarely important enough to be noticed, let alone filmed.
DAMY