Process flow diagram - Typical oil refinery. This is a schematic process flow diagram of the processes used in a typical oil refinery. This process flow diagram (PFD) example was redesigned from the Wikimedia Commons file: RefineryFlow.png. [commons.wikimedia.org/wiki/File:RefineryFlow.png] This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license.
Each gym also provides its members with access to state-of-the-art equipment. While members need to be 18 years old to sign up individually, those who are at least 14 can sign up with a parent or legal guardian.
Only with the express permission of their parents, I will allow 16 years old to be unsupervised. I would be really concerned about liability with what you're describing, I also think that having kids running around would be annoying. The gym I participate with only allows children over the age of 13.