I’m a massage therapist who’s been stretching athletes and clients since the 1980s. For the past 25 years, I’ve conducted seminars to show personal trainers how to stretch their clients safely and effectively.

In addition, I literally wrote the book on assisted stretching. It’s sold more than 150,000 copies since the first edition came out in 1994, and been translated into six languages.

I tell you that for two reasons:

First, I have a professional stake in the answer to this question. I’ve invested close to 40 years in massage therapy and facilitated stretching. Second, I’ve seen the benefits. I know it helps clients feel better, move better, and perform better.

But I’ll be the first one to say that trainer-assisted stretching isn’t right for every client or every trainer. Like so many other questions raised by fitness professionals, the answer to “should trainers stretch their clients?” is an emphatic “it depends.”

It’s not even a single question. As I see it, there are four questions:

  1. Should trainers in the “me too” era simply avoid touching clients at all, for any reason?
  2. If a client asks to be stretched, or gives permission for assisted stretching, is this something personal trainers are qualified to do?
  3. If they are, is it actually a good idea? Does stretching produce genuine, lasting benefits?
  4. Are there risks to stretching clients that might outweigh any benefits?

Let’s take them in order, and then I’ll show you how to stretch clients safely and effectively, if it’s something you decide to include in your workouts.

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Should you touch clients in the “me too” era?

Lots of trainers these days are cautioned not to touch clients. It’s a foreign concept to me after four decades as a massage therapist, but I understand the reason. Although I’ve never witnessed anything untoward, I’ve certainly heard stories about trainers who make assisted stretching look like foreplay.

There’s a pretty easy rulebook to follow:

  • Ask before you touch.
  • Be aware of the power differential in your relationship.
  • Most of all, be aware of your body position relative to the client’s. When you’re down by the ischial tuberosity, you’re out of bounds.

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Are you qualified to stretch clients?

To the best of my knowledge, the major organizations that certify personal trainers don’t include rules for stretching clients within their scope of practice guidelines.

In general, your role as a trainer is to evaluate each client’s current fitness level, and then design, implement, and supervise an appropriate exercise program, based on their stated goals. Stretching certainly falls within these guidelines.

But this assumes you know what you’re doing. We’ve all seen trainers performing stretches on clients who do it poorly. That’s what fuels the controversy over trainer-assisted stretching, and leads to the idea that trainers shouldn’t do it at all.

Trainers have lots of opportunities to learn specialized stretching techniques. The best are face-to-face workshops with supervised practice. You could also get certified in a particular system for flexibility or mobility.

The next-best option is to study online, watch videos, practice the system however you can, and gradually integrate assisted stretching into your practice.

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Does assisted stretching actually increase a client’s flexibility?

The short answer is yes: When you make trainer-assisted stretching part of each training session, your clients will indeed improve their overall flexibility.

But it’s also true that clients will get little to no benefit if they only stretch when they’re training with you. You need to show them stretches they can do on their own, and encourage them to do those exercises on non-training days.

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You also need to make sure they’re doing the stretches correctly. People are creatures of habit, and if they’re doing something wrong, they’re going to continue doing it wrong until someone corrects them.

If you ask how stretching increases flexibility, that’s a more complicated question. Twenty years ago, we had a perfect explanation of what was going on. We were sure that stretching lengthened the tissue. Today we have a fair bit of evidence that you’re not getting any change in length.

What changes is the stretch tolerance. The tissues are allowed to lengthen during a stretching exercise because the nervous system learns not to perceive it as a threat. To the client, what felt “too tight” no longer feels that way.

Are there risks to stretching your clients?


Hypermobile clients, for example, don’t need more flexibility. Their muscles aren’t strong enough to provide stability at the end range of motion, putting them at high risk for sprained joints (and relatively low risk for muscle strains). That’s their weak area, and that’s what you should work on: building strength to control joint movement.

There are also risks to stretching clients incorrectly, as I’ll explain in the next section.

You have to assess each client not just for how much flexibility they have, but for how much they need. A high school cross country runner has very different needs from a dancer or gymnast, just as an adult client who runs half-marathons has different needs from one who does yoga.

At the same time, you have to consider the risks of your clients not working on their range of motion. That’s especially true of your middle-aged, mostly sedentary clients. As I’ve gotten older (I’m now 70), flexibility is more important to me. I don’t recover as fast from aches and strains, and I certainly don’t want to lose the ability to do simple things like bend down and pick something up off the floor.

Which brings us to the most important question: If you decide your clients will benefit from trainer-assisted stretching, what’s the best way to do it?

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How to stretch your clients safely and effectively

Trainer-assisted stretching generally falls into three categories:

1. Passive stretching

The trainer does all the work to stretch the client. It presents, in my view, the least benefit with the most risk. It doesn’t expand a client’s active range of motion, and there’s a genuine risk of injuring the client by overstretching the tissues.

2. Active isolated stretching (AIS)

The basic idea: If you stretch a muscle as far as it can go, the nervous system will perceive a threat, and the myotatic reflex will prevent it from stretching any farther.

But if you hold that stretch for just two seconds, and then relax the muscle, the myotatic reflex won’t have time to kick in. And if you repeat the stretch multiple times, the nervous system will allow a greater range of motion.

To make the targeted muscle relax, you contract its opposing muscle. So if you’re stretching the hamstrings, you’d lie on your back, raise your leg by activating your hip flexors, then pull the leg back into a deeper stretch for two seconds, usually with the help of a rope or strap around your foot. You’d pull on the ends of the strap to stretch the hamstrings, then bring the leg back to the starting position and repeat the maneuver.

In the trainer-assisted version, you would take the place of the rope, pushing the client’s leg into the deeper stretch. The client’s activation of the hip flexors reduces the risk of injury, but doesn’t eliminate it. A trainer who’s too aggressive can still cause problems.

3. Proprioceptive neuromuscular facilitation (PNF)

Like AIS, PNF involves contracting and releasing the targeted muscles. Because there are multiple versions, both active and passive, I’ll focus on my specialty: facilitated stretching.

It’s unlikely to cause an injury because the client does the actual stretching. The trainer’s role is to assist with an isometric contraction, which again is performed by the client. At no point does the trainer stretch the client’s muscles beyond their active range of motion.

Let’s look at how to do it.

The three-part facilitated stretching sequence

Each stretch has three steps:

Step 1: The client moves a limb to its end range. If the target muscle is the hamstring, this would be a straight leg raise.

Step 2: The client isometrically contracts the target muscle for six seconds, pushing against resistance offered by the trainer. It could be your shoulder, leg, or hand. The point is to provide something solid enough for the client to activate the muscle while the limb remains stationary. (It doesn’t work if the client overpowers you.)

Step 3: The client relaxes and inhales deeply while you support the limb in the same position. Then the client exhales and actively moves the limb again, this time achieving a greater range of motion, and thus a deeper stretch of the target muscle.

Now you move into the new position to provide resistance as the client repeats the isometric contraction.

You can stop there, after two repetitions, or do it a third time if you think the client can achieve a little more range of motion.

But at no point will you push or pull to force the deeper stretch.

Here’s what a facilitated hamstring stretch looks like:

Final thoughts about trainer-assisted stretching

I’ve written this article from the viewpoint that these three things are true:

  • Flexibility is valuable for everyone.
  • Flexibility is important enough to include in most training sessions with most (but not all) clients.
  • Trainer-assisted stretching is the most effective way to help clients improve their overall flexibility.

Even if you agree with all three statements, you may decide it’s not for you, and that’s fine. Maybe you don’t want to be that hands-on with your clients. Maybe they don’t want to be touched. Maybe your gym doesn’t allow it. Or maybe you don’t feel you have the knowledge or experience to do it safely.

I respect all those reasons.

But if you are qualified to stretch clients, or plan to become qualified, here’s the most important thing to know:

Stretching should always be pain free.

If a client tells you something hurts, or flinches or grimaces during a stretch, try a slightly different position, or tell the client to use less force on the isometric portion of the exercise. And if that doesn’t help, avoid stretching that muscle until you can figure out why it hurts.