Seems to be that gymtrained guys either wait to see what sort of rest time you have and then when you're nearly at the end of your next set and subtly position themselves slightly in your line of sight, ready for when you take your focus outside of your body. They then signal with raised eyebrows and a bob of the head, you show them 3 fingers to show you've got 3 reps left, they smile and wait for you to stop before asking if they can jump in or should wait for your last set.
But if it's Brotime in the gym, guys appear in your face or speak in your ear just as you're starting your first rep. Headphones are very useful for those, as if you can't hear them, they bugger off and pester somebody else (and leave a trail of unracked weights and arse sweat surfaces behind them as they go).
Although this may be a prejudice being formed as a result of Functional Fitness Circuit Cross Fit Testosterone Classes starting in the gym and gradually infesting the entire place because they can't possibly keep the equipment or activities to the designated section and clearly, everybody needs to see them doing bar handstands in front of the cleaning station.
In other news, I might have a theory about the days where performance has improved. Magnesium. Looking back at better sessions and where I've done some fairly intense (for me) endurance things, it has coincided with higher intake in food and significantly more so when I've had one of those wanky waters.
After some research, I've bought some Magnesium Glycinate (no desire to experience the effects of citrate) and I'm going to see if it does do anything or not; if anything, I'm primed for a nocebo effect, as I'm a very cynical person.
Planning to go to the gym tomorrow before it gets too hot. If I do go, I shall report back if there seems to be any discernible difference.