The plank is the worst core exercise in the opinion of physio Dave O’Sullivan and here he explains why

There, I said it! After six years of working in professional sport and treating hundreds of runners I cannot remember the last time I prescribed a traditional plank exercise.

I have given up trying to coach the plank because it is the exact opposite pattern that athletes need to be in to achieve success. When was the last time you had a tight back from excessive running, sitting or training? When was the last time you had “tight” abdominals from running, sitting or training? Ever? I have never had an athlete come to me and ask “can you loosen off my abdominals because they’re feeling really tight?”

If I had a pound for every time an athlete came to me and said “could you loosen off my lower back – it’s tight” – I could probably retire after six pre-seasons in professional rugby and working with hundreds of runners.

Muscle pattern

Despite the misconception, runners have tighter and stronger lower-back muscles and are actually stuck more in a particular pattern than rugby players despite the difference in muscle mass!

Through assessing masses of runners, I have found a particular pattern that most runners adopt to run in a certain way. At my clinics and because of our unique talus orientation scanning I am now able to show runners how they are stuck in a particular pattern.

We are hopeful of bringing this pattern to light within the next few years with the help of the University of Huddersfield and research this further. The plank exercise is not the main culprit for this pattern, but it reinforces the bad pattern that causes runners to become injured!

“I have given up trying to coach the plank because it is the exact opposite pattern that athletes need to be in to achieve success”

One of the main groups of muscles that are a big problem for runners is the two iron rods going either side of the spine – the erector spinae muscles. These muscles are prominent in every runner I see and it is these muscles that are overactive and ultimately cause havoc on the pelvis and torso.

Why do the plank exercise?

Almost every day at my clinic I hear, “I have a strong core, I do loads of core training such as planks and side planks.” The core is another article in itself, but 99% of people would agree that they do the plank exercise to work the abdominal muscles and mainly “to get a strong core”. The problem though, is that the two big iron rod strips going up either side of your spine are the two sets of muscles that are mainly working during a plank no matter how good your technique is and are further driving you into this lethal pattern.


Try to perform a “good” technique plank and hold the position for 10 seconds. I want you to be aware of where you feel you are working – the backside of your body and spine or at the front? If you want to take this further and have no back problems, I invite you to stay in the plank position for 60 seconds and then stand up and feel where the majority of the tension is now being felt.

You will find that 99.9% of athletes will feel the two rod muscles working more than the front part of the spine. Do not get me wrong here – the abdominals will be working somewhat and you may feel this a little, but the majority of tension is felt in the backside of the spine and core. These are the exact muscles that are over-working for most of the population!

Why is this?

Don’t worry – it’s not your fault! The front plank biases the lower back iron rod muscles. It places them in the best position to fire and the abdominals in the worst possible position to fire isometrically. Therefore, it is not your fault your abdominals will not dominate this movement. They are at a disadvantage from the get go!

Problems with the low-back muscles dominating

» Further arches your back, which most runners will suffer from in any case once fatigued. How many photographs have you seen of yourself at the end of a race with your back arched?

» Tips the pelvis forward, crushing the front of the cartilage on the hip joint, causing labral tears

» Pushes the hip joints forward out of the sockets and contributing to labral tears in the hip joints

» Makes the calf muscles work harder when running because the hips are pushed forward causing calf tightness and Achilles issues

» Increased tension in the neck causing tightness in the area or shoulder pain

» Increased tension over the L4/ L5 area of the lower back where the most common disc issues are located

» Pulls the ribcage out of position causing the shoulder position to be out, which can cause rotator cuff tears

» Disengages the big latissimus muscles on one side, which causes the shoulder joints to also pop forward and effect the same compensations as the hips causing labral tears

If you hold your breath and do not exhale correctly while doing the plank movement, this will exaggerate all of the issues above even more! The reason for so many hip and shoulder labral tears in the last few years is that everyone’s pelvis and ribcage is living in the wrong positions due to a series of muscles and the iron rod muscles are a big part of this problem.

I hope you can see now why the front plank is a poor core movement to help strengthen the abdominals. The risk-reward ratio of doing this exercise means it is simply not worth it – the problems far outweigh the benefits.

All of the runners that I have treated have had the same muscle dominance around the core area and the symptoms just present in different areas of the body.

What’s the alternative?

Opting for more dynamic movements where the abdominals need to lengthen and shorten may be much better options to allow the core muscles to function as one and to avoid biasing the low-back muscles. I have devised my own runners’ core programme to allow the core muscles to function, as they need to when running.

Keep an eye out for a future article on the “extreme plank” – a great alternative to the front plank, especially if you want to train your abdominals and not your iron rod muscles in an isometric stabilisation fashion. This will be featured in AW in the coming months.

» Dave O’Sullivan is clinical director for ProSport Physiotherapy Huddersfield and the head physio for Huddersfield Giants Rugby League Club. Information and running blog: