liamrosen.com blog - Why You Don’t Need a Personal Trainer

If a personal trainer just taught you what was effective and then let you do it, you'd outgrow needing them pretty fast.

Most of the trainers at my gym have their clients doing light-weight, high-rep routines of ridiculous exercises involving bosu balls, swiss balls, and 5-8lb dumbbells. Then I see them working out when they're off-duty doing squats, bench press, cleans, etc. I'm guessing they just don't want to scare their never-picked-up-a-weight-in-their-life clients with the big weights, especially the women. Dumbbells aren't intimidating in the least, and the only things the trainers have to do is convince their clients that standing on one leg or on a bosu ball will help their stabilizers (which may be so, but to actually be effective wouldn't you need to work those stabilizers with something higher than 5lbs?) and that "HIGH REP + LOW WEIGHT = TONE TONE TONE!!!"
- Dying Atheist

Okay, so how is my trainer so in shape if he or she doesn't know anything?
And I would also agree most trainers are/have been active their whole lives, probably did High School sports, etc., so they don't need heavy weight routines to maintain their physiques, and aren't necessarily trying to improve, they are on perpetual maintenance programs by virtue of their work and generally active lifestyle.
- eclectic taste

Most trainers in random non-hardcore gyms took at most a weekend long course to get some crappy certification. They are really salespeople, not trainers. If they showed you the right way to exercise, you might keep coming back, and their business model is based on a large percentage of paying members not actually using the gym. If you think the way to exercise is hours a week of mind numbing dumbell curls while standing on a bosu ball, you're much less likely to utilize the gym's resources than if you discover the wonder and joy (and actual utility) of lifting heavy weights.
- fed_dude

Just in case you were curious what it takes to be a PT at most chain gyms:

24 Hour Fitness

• High School Diploma or GED required
• Current CPR certification

24 Hour Fitness prefers that candidates possess either a certification or degree as listed below. Other certifications will be considered based upon your experience. If you have not yet completed your degree or certification, and wish to be considered, please contact your local Club Manager for more information.

Never been a personal trainer before? NO PROBLEM! Just be strong enough to rack the squat bar and we'll set you up with this nifty red shirt.

The purpose of trainers, at least in commercial gyms, is not to train people in the most efficient way possible, but to make money. Why do so many trainers rely on gimmick exercises like swiss ball pushups, 5-8lb dumbbell flys, and other isolation work? Because clients see those exercises, think they look cool, and would be disappointed with anything else. Gyms also take on a fair amount of liability with clients. That's why big, scary compound lifts are out and the trainers are happy to point people to the nearest machine.

Most trainers in random non-hardcore gyms took at most a weekend long course to get some subpar certification. They are really salespeople, not trainers. If they showed you the right way to exercise, you might keep coming back, and their business model is based on a large percentage of paying members not actually using the gym. The two requirements to be a trainer at 24 Hour Fitness, by the way, are a High School Diploma or GED and Current CPR certification. Actual personal training certifications are preferred, but not required.