You're probably over analyzing this. I don't need someone to tell me how to run if I want to go for a run, regardless of my experience level. But sure, having a personal trainer is important for certain types of workouts.
But plenty of people have permanently damaged their knees by consistently running without getting advice on how best to do it.
You don't need a personal trainer for that. But asking someone "to tell me how to run" ain't a bad idea, even if it's a question on a running board on the Internet.
"But plenty of people have permanently damaged their knees by consistently running without getting advice on how best to do it."
The people who read running boards all the time roll their eyes at stuff like this. Saying that running will hurt your knees is the running equivalent of "The GPL will infect your codebase." It's not true, but it sounds scary.
Usually, if you ask runners how to run, they will say something like, "It's not that complicated. Run more miles, slowly."
OTOH, "Runner's Knee" does seem to be a serious condition affecting a lot of people (much like "Fencer's Knee", which I'm more familiar with). From the same subreddit:
I trained with one on the Starting Strength lifts for 4 months. Made crazy gains, but I ended up stopping after an injury. I was not listening to my body the way I would have if I hadn't had the trainer.
I'm starting Crossfit now, and my number one goal is zero injuries. I like that it's more of a class format than it is a one on one training format. I can go at my own pace.
I used to think the same way. But gyms vary widely in quality and culture. And you can go at your own pace, nobody is going to make you do more when you're ready to stop.
I personally would prefer to just lift. But unless you're pretty lucky, or are willing to invest the time and expense, you won't have access to a gym with decent equipment. Since convenience is a huge factor in lifestyle choices like working out, you need to choose amongst the activities that are close to you. Once I graduated from cardio at Planet Fitness, the only place to go really is Crossfit.
Allow me to please add another dimension to this discussion. First a couple of facts, South Africa is in top five set of unequal societies in the world (the rich are really rich, the poor very poor). Less than 1% can afford personal trainers. Obesity related illnesses now take up bulk of health budget. Not to discount the value of personal trainers but in certain countries/scenarios it is just best to get on with exercising.
People have been working out without "professional trainers" for millennia. Yes, you can be injured occasionally (but you also can with a trainer), but if you don't overdo it you'll be fine.
