Science Summary: Benefits of a Personal Trainer Supervising Your Workout

Science Summary: Benefits of a Personal Trainer Supervising Your Workout

I read this article around my second year as a personal trainer and it validated my career for me.  The TL;DR here is that direct supervision by a fitness professional dramatically improves the return on investment from exercise.

For my personal trainer friends, this is worth passing out to your clients and to potential clients to show them the benefits of a personal trainer.  For my clients, here’s some science that proves I’m not a complete quack.


What They Did

An article published back in 2010 in the Journal of Strength and Conditioning Research titled “Influence of Supervision Ratio on Muscle Adaptations to Resistance Training in Nontrained Subjects” (which can be found here) studied the effects of having someone oversee your workouts.  In this study, conducted by researchers Paulo Gentil and Martim Bottaro, 124 participants were grouped into either high supervision or low supervision groups.  In the high supervision groups, 25 participants were supervised by five coaches.  In the low supervision groups, there was only one coach per 25 participants.  After being divided into these groups, every participant was placed on the same training plan and was tested on one repetition maxes for knee extension (quad strength) and bench press (compound upper body strength).  The training plan consisted of the following exercises:

Exercise Group A: Bench press (barbell), Leg press 45, Lat pull down (supinated), Stiff legged deadlift, Seat ups

Exercise Group B: Seated bench press (dual axis machine), Seated leg press, Seated row (dual axis machine), Seated knee flexion, Seat ups

Exercise Group C:  Seated bench press (machine), Seated row (low pulley), Knee extension,  Knee flexion  Seat ups

Coaches for the study were not told the purpose of the experiment and were tasked with maintaining attendance, improving technique, and encouraging maximal effort from the participants.

What They Found

At the conclusion of this study, the researchers found the high supervision group showed an 11.8% improvement in knee extension maximum strength and a 15.9% improvement in bench press maximum strength.  In the low supervision group, there was no improvement in knee extension maximum strength and a 10.22% increase in bench press maximum strength.

What It Means to You

The takeaway from this piece is that having someone supervise your workout directly improves the effectiveness of your exercise and the progress you will see.  This is due to many factors.  From my personal experience as a personal trainer, the top two factors are the accountability, my clients rarely miss a workout or have easy days, and progression, I encourage my clients to go heavier than they would push themselves.  In this study, they found a direct correlation between the amount of supervision and the effectiveness of an exercise program which means one of the top benefits of a personal trainer is that their presence alone will get you results quicker than you will see on your own.

Now the same can be said for having a dedicated workout buddy who fills the same role, providing accountability and encouraging progress beyond what is comfortable, but, sometimes our gym buddies have great ideas and sometimes they don’t.  Without education and experience, an untrained friend probably won’t be as effective as a professional.