Avoid giving unsolicited advice in the gym for two reasons. Number one, they will tend to act defensive and reject your criticism. Number two, your advice could be wrong.
Unless their technique is threating themselves and others, avoid giving advice. If you really want to help, however, become their friend first.
Areas like entrances, walkways and aisles should be reserved for foot traffic, not walking lunges, kettlebell swings or jumping rope. You can hurt passersby or hurt yourself.
Always exercise in proper areas, free from people walking by.
Use a shoulder machine as a shoulder machine—not as a complex glute exercise.
First, it takes the equipment away from someone who actually wants to use the machine correctly. Second, you could break it and hurt yourself. (I doubt the manufacturers will be liable.)
I once saw a gentleman use an incline bench while the plates slid off one end. Before I could reach him, the plates dropped, the bar flew up, and everything crashed on the other side. Fortunately, aside from his bruised ego, he was fine.
“Maybe you should use this,” I said showing him a weight collar.
You must attach weight collars when using barbells. Regardless of the weight, the plates will slide and ruin your balance.
Give everyone exercising a cushion of a few feet. You never know if they will lose control and dump the weight or if their exercise involves a lot of movement.
For example, I’ve seen people almost lose their faces because they squeezed past a person doing an Olympic lift. Bad idea. Instead, wait a few seconds until they finish. Also, if someone is doing a heavy lift (like a squat, deadlift, overhead press, etc.), never walk right in front of their line of sight. It’s distracting and rude.
And if someone is doing pushups, please avoid walking over him.
Crowded gyms are a free-for-all: all the benches are taken, everyone wants to use the same dumbbells, and everyone asks you, “How many more sets do you have?”
Always maintain etiquette, especially during peak hours. If you see an open bench with someone standing nearby, ask before using it; if it’s occupied, however, they’ll almost certainly let you work in.
No one wants to see a loogie or a piece of gum floating in the drain. Use the trash can.
You risk injuring yourself or someone else by walking aimlessly throughout a crowded gym. You could walk into someone doing an exercise, interfere with someone’s lift, or—quite easily—walk into a machine.
This should be obvious, but it still happens. Wait until you stop moving before you text.
Sometimes a trainer will teach their client an awesome exercise that grabs your attention. Never spy on them and try to (poorly) mimic the exercise yourself. It’s far better to ask them what they’re doing—odds are they’ll gladly teach you the movement so you can do it correctly.
Instead, eavesdropping to take a trainer’s exercise—and trust me, we notice—is disrespectful to both the trainer and client, especially because the client paid to learn something that you snatched for free.
This, for some odd reason, happens. Please respect other gym patrons and keep your clothes on for the duration of the workout.
As for guys trying to “show off,” the truth is that taking off your shirt and flexing only reveals approval-seeking insecurities.