Todd, good for you for trying to take these guys under your wing! As someone who works all day long with that age group (and knows how challenging they can be) I applaud you for taking the time. Not many people would.
My suggestion to you would be, instead of telling, try asking. Kids this age are figuring out how to be adults and a lot of times that involves them doing things that seem "adult" to them, and trying them on for size. For most boys this involves trying to be badass.
For kids that age in general, it involves experiencing freedom (without really considering the responsibility part that goes along with it--that comes in time as maturity develops). They also consider themselves indestructible and so any talk of blowing out their knees really, truly will be lost on them. They genuinely do not believe it will happen to them; mostly because they have Hulk levels of testosterone fueling their actions (and flooding their reptilian brains) so they genuinely feel like they are invulnerable.
They are used to adults telling them what to do all day long, and as teenagers who are indestructible and "know everything," more adults telling them stuff is not going to be effective. Peer reactions are also very important to them, and figuring out their identity means they are constantly engaging in social behaviors that will help them understand where they are in the pecking order. This explains their obsession with trying to compare themselves to you, etc. For them the world is very simple: according to them, a dude who can do a backflip is obviously way cooler than a dude who can't, and is obviously better-skilled. Developmentally and experientially, they have not even figured out how to see the small stuff, or the long-term relationship between hard work and success. In essence you trying to tell them is like trying to describe a rainbow to a blind person. They're just not there yet.
But they are probably so thrilled to find other people who train, which is why they're excited about meeting up with you guys again. Plus, you're adults, which (whether they want to admit it or not) makes what they do "cool," and automatically also makes you "cool" because most adults wouldn't do something as "edgey and cool" as FR (how naive they are)
So you are in a good position to leverage that and get them to come around. But you have to do it by asking, not by telling. They are not going to come around just because you say so. Instead, find out what their motivations are. How did they learn about PKFR? Why do they do it? What do they like about it? Did they/do they do other sports? Have they ever heard of David Belle? The Yamakasi? You have to find out about them to find out where you can find entry points to redirect their thought process. But you can't pull them down that path, you just have to show them and encourage them to take the steps on their own.
Encourage them to Google David Belle, Yamakasi, Jump Westminster, Pilgrimage, etre fort pour etre utile, etc. In your conversations while training, talk about what is important to you in parkour. But keep it short. Lead the training session, go ahead and tell them what to do without being bossy. It's clear they don't know how to train, they will probably be grateful (without realizing it) that you're willing to tell them what to do. When everyone shows up, start off with your normal warm-up, and just say, "When we train, we always start with (X) because (Y)." That's it, one sentence. Keep it short and focused on the movement and why you do it. If they start griping, reassure them that you will get to the "flips" eventually (don't call it "fun stuff" or "cool stuff" because by contrast you are making the conditioning/training "not cool/fun"). Try appealing to their macho/competitive side by offering challenges such as, "How fast can you make it up that wall?" Record everyone's time, and agree to all beat your own times by 5 seconds in a month or something. This engages their competitive side while subtly shifting the competition to competing against themselves rather than others. Also the challenge is something besides flips.
The most important thing you need to get them to reflect on is WHY. Ask them why they do freerunning. They will probably give you some answer like, "to get away from the cops" or "to be badass" or whatever. Accept it without approving of it, for now. It's just where they're at. But by being a good example yourself, and presenting the best options for them to choose to follow, eventually they will come around as they discover more about the "right" idea. If they've heard of Levi, and Ninja Warrior, you can get a ton of mileage by letting them know you know Levi and he's a really nice guy, and he trains 6 hours a day on just conditioning stuff, or whatever. I don't know how accurate my facts are, there; but hopefully you get my meaning. If you can connect what they perceive as "cool" to the real deal somehow, it could open their eyes and get them started seeking out the right ideas. Simply directing them to APK would help too if they're not familiar with it.
They are probably actually really intimidated after meeting some "real" traceurs and are covering it up with bravado (see above re: peer approval, pecking order, etc.) so by showing that you are really nice and validating their practice you will get farther than if you are all lecturey and stuff. You have to make it safe for them to admit (without admitting) that they were on the wrong path and didn't really know what they were doing. Eventually they will "admit" it by simply exhibiting changes in their thinking and their approach, and you just have to lead by example, and by acceptance of them, to get them there.
Just remember: ask more, tell less. The more you can find out about what PKFR means *to them*, the better equipped you'll be to help them.
I hope that made sense... I have a hard time articulating this stuff sometimes. But I know how kids that age tick. Hopefully there is some useful stuff in there for you. Good luck!
