I’ve seen trainers and fitness instructors gloating over the participants who have either hurled or collapsed during a training session. I’d never return to a session with someone like that.
But on the surface you need to ask what was going on before you rush to judgement. A new participant may not know that a big breakfast is not a good idea right before a 6am training. Or they may have been fighting the flu all weekend.
That’s why it’s always good to find how they’re feeling during warm up. You can gauge exercise intensity off their responses and with experience learn to judge body language that tells you a client is moving too hard or too fast or “just doesn’t have it” that day. Despite what we all want to think, clients don’t always tell us what they think is “bad” news.
Either way both trainer and client have a learning opportunity when things like that happen.
I have never seen that in all my 16 years of training clients.
With my personal training clients, I cannot even imagine how it could happen short of somebody already coming in sick and not wanting to let on. Even there I like to think that I would notice something wrong before it would manifest itself in such a drastic way.
As far as group exercise is concerned, I am teaching both water aerobics and MELT. I have seen people in water aerobics sometimes pushing themselves harder than they needed to which may have let them to get dizzy and light-headed but never more than that.
If I had to assume that I was the cause of such misery, I would have to question my ability as a personal trainer.