I was working out minding my own business.
Did a set of bb rows, I would say "heavy".. finished the set and walked tll the corner to take a breath and rest.
There was a man in his 40's..probably a kickboxer or something..as I was passing in front of him to my next set he started throwing punches to the air and kicks, pretty fast I would say but who cares.
whats the purpose of this? probably to "intimidate" me or something? 
he felt threatened and dominated by other men including you and wanted to show you that he could dominate you with his fists and feet if he wanted to, but basically he s restraining himself from killing every other males because he s too wise for that. He's too humble. If you feel bad somewhere, dont go in that place, period. These people are so frustrated about their own lives. Their fat wife, or their divorce, their kids who dont love them and they dont love, their shitty job, their shity physique, being old and knowing some younger people are smarter than you sooner and will have a better life...
Proof you can be 14 y/o or 40 y/o and be inconceivaly insecure and immature.
On a side note, this is why the gym is for morons. At some point, after some years, if you dont get sick of it it means you ve become a moron too, and adapted by following a moronic attitude to fit with them.
