One thing about the gym folk like the kids you mentioned is that their lack of patience keeps them reasonably trouble free. Always freak injuries out there but oftentimes the training strategies they’re following aren’t rational and are the result of something they’ve misread online, in Men’s Health or Muscle and Fiction etc. (my son in law’s bibles) and, lacking a fundamental foundation in the nuts and bolts of exercise science try the equivalent of a “lose AT LEAST 10lb/week” diet come-ons or similar promises for getting out of debt.
I’m thinking that far more lose interest when the first “stall” hits …usually by mid February for the NewYear Resolutionaries (pretty much anything works for 6 weeks with a novice trainee)…and disappear because of boredom rather than injury.
It’s been my good fortune to stumble across decent trainers even back when I was a n00b…as well as being quick to learn from my mistakes and willing to follow advice when my experiments didn’t work as planned.
Whether it’s Future Proofing the body or ones finances the real difficulty comes from digging in and staying consistent over the l9ng haul.
Here’s one strength training programme I can recommend (provided all the caveats about technique and whatnot)…and actually doing it, of course.