Rethinking Abdominal Exercises

What Science Actually Says About Ab Exercises

Let’s talk about prescribing abdominal exercises as personal trainers. Every client wants to see their abs, and most trainers use this as a selling point (not necessarily a bad thing). When you are discussing your clients goals they may say something like, I want to tighten my tummy, lose the belly fat, or see my abs. They may even deny that they have any abs to begin with.

The purpose of this article is to see the flaws in our current core training, and change the way we approach prescribing abdominal exercises.Prescribing Abdominal Exercises

Where have we gone wrong with training abs?

When the average person thinks of abdominal exercises… crunches, sit ups, and leg lifts come to mind. If they are familiar with exercise, they may even throw in planks. Sometimes we as health and fitness professionals fall into the same rut. To see why this could be a problem we have to step back and look at our clients lives outside of the gym.

What position is their body in the majority of the day? Personal Trainer AbsAre they a desk worker? Do they drive for hours a day? This means many of our current and future clients spend most of their day in hip flexion.

The Science:

One of the primary muscles that becomes tight with hours of sitting is the Iliopsoas. It is two muscles often grouped as one, and has its origin from the T12 to L5 vertebrae pulling anteriorly on the lumbar spine, or into lumbar lordosis. These muscles are often called the hip flexors because they do just that, flex the thigh at the hip.

Now we have a desk worker walk into our gym, that sits 6 or more hours a day, and wants to see his abs. This is where correct exercise prescription is so important!

Why would we want to encourage hip flexor activation if they are already tight and overactive in these muscles?

(stay tuned for a refresher on the CNS, reciprocal inhibition, and synergistic dominance coming in a later post. In the mean time, here are some definitions you can use as a reference.)

The answer is you don’t want to do that. While most of our clients want and need core strengthening, jumping right into 3 sets of leg lifts is not actually helping them. It is our job as professionals to know what is best for our clients and not just prescribe them what they think they need.

So what abdominal exercises should we be prescribing?

Teaching your clients to activate their deep spinal stabilizers in multiple planes of motion would be a better prescription than more lying leg raises. Start with a correct plank with appropriate posterior pelvic tilt and “drawing in” at the navel. Then progress to resisting rotational movement through activating the appropriate spinal stabilizers.

Not only will your client feel their whole core working, you will be teaching them correct muscle activation that has been linked to decreases in non-specific low back pain.


Don’t fall into the trap of only prescribing abdominal exercises that are very hip flexion dominant. This will reinforce bad movement patterns and increase their risk of injury. Focus more on full body stabilization with proper spinal and pelvic alignment.

Have any questions or comments? Leave them below!


About The Author

Adam McCluskey

Doctor of Physical Therapy Candidate, Corrective Exercise Specialist, Certified Personal Trainer