I put lots of updates on the
FB page for the gym. A while back on this forum, someone said, "a personal trainer gets the first 50% of someone's performance, a top sports coach gets the last 5%." He meant it as an insult and later apologised, but I said: no, you're right. Let's think about it: take any world record in lifting, running or whatever, get a person to 50% of that and... you've totally changed their life. For an 80kg 30yo man this would mean a 140kg squat, for a 60kg 50yo woman a 70kg squat, a 50yo man a 30' 5km run, his 50yo wife a 24m discus throw. For previously sedentary people with the usual run of health problems, plus some from age - that's life-changing stuff. After that is awesome but won't hugely change their life.
And most can do that 50% without having to dedicate their whole waking lives to it, they can hit 50% WR with a few sessions a week over months or at most a year. Past 50% WR will usually require a very dedicated effort, to the exclusion of other things, and the training will also be much more individual. They get that far, they might graduate to a sports-specific coach. I currently only have 2 lifters over 50%, a 67yo 63kg woman with a 220 PL total to the 325 record, and a 25yo 108kg guy with 605 vs 945 (he had not competed when he started with me, but could have done 425 or so). Those 2 don't want to move on, so we do our best to figure things out.
So this is how I think of it, getting people to 50%. It's only a pass mark, but is far beyond what most ever manage on their own.
This afternoon we had a 40yo IT guy (3 weeks training, just pulled his bodyweight), a 73yo retired housewife (6 weeks, never trained before in her life, today just did 12kg box squats, 14kg presses and 50kg rack pulls), a 30yo woman ambo (on deload after first 3 months, has done 73.5/35/85), her fiancee an emergency physician (few weeks, previously very sedentary, did today 40/30/60) and a 25yo supermarket produce manager (6 months, then break, building back up, has done 130/95/140). Then another bunch in the evening. So we get all sorts.
If someone wants to be a personal trainer, they have to realise this is what they'll be dealing with: people of all ages and backgrounds, mostly previously very sedentary, some motivated but most not, lots of injuries and health conditions you have to work your way around, and these are people for whom 50% of the world record will be a big deal. It's not easy and you won't make much money, because the real money in the fitness industry is not in actually training people, it's books, DVDs, seminars, selling programmes online, and so on.