How Young is Too Young to Be Left Alone at a Gym in Maine?

This question honestly comes up a lot. It's one of those questions you might think about in the time being, but don't actually try to figure out. Well, I've been trying to figure it out.

The other day, I was working out at a totally different gym than the usual two that I go to here in Portland, Maine. I was pretty surprised by the amount of children there that were running free that didn't look old enough to be, well, running free around equipment.

They ranged from about nine to 15 years old. Honestly, my first thought was how dangerous that situation could become if one of them tripped and knocked their head on a free weight.

So is this like the legal drinking age type of thing and becoming legal? Is there a certain age that children need to reach in order to be dropped off and left at the gym alone?

Backed up by maine.gov,

I used the standard gym, planetfitness.com, for more information. Apparently, you only have to be 13 years old to open a gym membership (in Maine and nationally). This is what their website says:

"You can join PF starting at the age of 13 with a parent/legal guardian’s permission; they must be present with you during the sign-up process. Members aged 13 and 14 must be accompanied by a parent or guardian when they work out. Members who are 15 to 17 years old must have a signed waiver from a parent or guardian on file. Please note that any PF Black Card® guests must be 18 years old with a valid ID, unless they’re accompanied by a parent or guardian."