Personal Trainers Exposed


Personal trainers pride themselves on being students of fitness, promising results using the latest and greatest secrets from nutrition and exercise science.  Most personal trainers, however, exhibit substandard knowledge of strength and conditioning training, prescribe ineffective or unsafe training protocols, and justify their methods with pseudoscience or “experience.”  As a trainer, I shudder at the things I see fellow trainers foist upon their clients.

What’s worse, many of the mistakes are easy to correct.  If your personal trainer does some of these things, confront him and ask him to justify himself.  A wealth of science based information is available to fitness professionals, but most make little use of it.  Instead, they rely on habit, misconceptions, and empty promises to market their businesses.

Unstable Surface Training

Trainers claim that unstable surface training will improve balance and ‘core strength.’  Standing on a balance or BOSU ball while performing exercises forces a trainee to constantly adjust his weight or fall over.  It does require quite a bit of skill to do well.  Unstable surface training invariably teaches trainees to balance on unstable surfaces more effectively, but the question is: does that accomplish anything worthwhile?  Does training on a BOSU ball make a trainee stronger, jump higher, run faster, or burn more fat?

In short: no.  Unstable surface training is a completely ineffective method of training for healthy trainees.  One of the few controlled studies to answer this question, from the Human Performance Lab at UConn, looked at how university-level soccer players responded to unstable surface training. (You can read the abstract here.)

The authors concluded, “These results indicate that UST using inflatable rubber discs attenuates performance improvements in healthy, trained athletes. Such implements have proved valuable in rehabilitation, but caution should be exercised when applying UST to athletic performance and general exercise scenarios.”

The subjects in the study who trained on unstable surfaces didn’t get as strong or fast as the subjects who trained the old fashioned way with a pair of shoes on the floor.

Let’s look at one common case of unstable surface training: standing on a BOSU ball while performing an isolated arm movement.  The trainer has her client stand on the ball, hands her a pair of 5 lb dumbbells, and instructs her to curl for 10 reps or so.personal trainer

What does this training accomplish?

A trainee spends so much energy and concentration on standing upright that he can’t lift a meaningful amount of weight.  Because he can’t lift much weight, the training stimulus to the biceps is insignificant and the trainee doesn’t get stronger.  If the client performs the same exercise standing on the floor, he can lift a meaningful load and see a real training effect.

I said the short answer is no, unstable surface training is not effective.  The long answer, however, is yes, it can be effective in very specific situations.  Trainees coming off injuries will find unstable surface training very useful because it retrains the musculature around the joint to respond to quick changes in loading.  After an ankle sprain, for example, unstable surface training will help retrain your muscles to tighten up as your ankle starts to roll.

While I haven’t talked at all about the safety of unstable surface training (it’s usually pretty safe), some personal trainers have managed to make it dangerous (see below). But, in the end, my real criticism is simply that it doesn’t work. Show me a strong and fit individual balancing on a BOSU ball, and I’ll show you someone that built their physique with old-fashioned training before trying their hand at squatting on a ball filled with air.