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Coaches Blog

Why Posture = Power

Updated: Apr 21, 2022

I am sure you all have heard people say, “Stand up straight” or “Stop slumping over,” and you probably corrected your posture at the moment and then went right back to your routine. Aesthetically, a nice upright posture looks better, but that’s not why it’s essential. Good upright posture is essential because it promotes the muscles and joints working most efficiently. This means that maximizing your posture means maximizing your power. This blog could be stretched out to a chapter of a book, but I will try to keep it as brief and concise as we don’t have all day.

The human spine is constructed in a way to best absorb ground reaction forces. Therefore maintaining the optimal curvatures of the spine is vital to keep the vertebrae stacked on top of each other to optimally attenuate these forces.

In addition, abnormal curvatures are created by or cause muscle imbalances which place the muscles at less than optimal length. Below, I have briefly described how abnormal postures can impact your swim, bike, and run.

The Swim

In swimming, one of the most important things is to be as long as possible and stay on top of the water. Kyphotic, or hunched over posture shortens your length in the water. As compensation and to keep looking forward, your head tilts back and comes forward, thus making it much more difficult to maintain that long stiff board that we are looking to achieve in swimming.

Also, with increased flexion in your upper back, your shoulder joint structurally cannot allow your arm to lift as high. Just try it out. Sit in a slumped-over position in your chest and lift your arm out in front of you as high as you can. Note the energy it takes to lift your arm.

Now, extend your upper back and lift your chest and then raise your arm up high. You should notice an ease of movement and increased range of motion. Now think about repeating that movement thousands of times during your next swim session and how much extra energy it costs when your body is fighting its posture. There are many other aspects of posture that impact swimming, but this was just an example.

The Bike

On the bike, you can get away with some posture deficits. Often the bike can contribute to poor posture, especially if you spend a lot of time in the aero position outdoors where you are leaned forward and looking forward, so your head is tilted up. Your posture will lose you the most power on the bike in your low back and pelvis. For those with a more than normal lordotic curvature (arched) in the low back, this leads to tipping your pelvis forward, shortening the hip flexor muscles in the front, and lengthening the hamstrings. The result is an imbalance of power where the hamstrings are not at optimal length to create maximal power. It can also lead to low back pain.

Typically, when you have pain in an area, you will also be losing power. There are many other areas where posture could be causing you to lose power on the bike, but this is one of the most common.

The Run

Of the three, running is the activity where the most gravitational forces are going through our spine and thus most important to keep natural alignment. It is of utmost importance when running to stand as tall as we can as if being pulled to the sky from the top and back of our head and then from there lean forward slightly. This will result in all of the vertebrae of the spine being stacked on top of each other and promote our foot landing beneath us.

If you flex at the hips, you will most likely strike the ground with your foot out in front, and the ground forces will fight against you. If you tend to tip your head back, which many people do when fatigued, then you will kick in the muscle in the front of your neck. These muscles are secondary muscles for breathing. We don’t want these to get tight, making it more difficult to lift and expand your chest for respiration.

Optimally, when running, we want to strike the ground with our foot underneath us so that we push straight down into the ground. Thus it is pushing straight back up through our kinetic chain. From there, it is up to our most powerful muscle in the body, the glutes, to absorb those forces and rebound with explosive force as we extend our leg back and propel forward. This is the way that the body is made to work most efficiently.


As you can see, the good posture that everyone is always harping on you about is not just for looks. There is a significant association between posture and power. Don’t let this depress you, though, because we are all fighting our body’s tendency to go into poor posture. More so, the next time you are reminded about your posture, remember the impact it may be having on your power in sport. This may help you be more motivated to self-correct and be more aware throughout the day.


Aaron Scheidies is a USAT Level 1 Certified Coach and licensed Physical Therapist. A graduate of Michigan State University with a degree in Exercise Physiology, Aaron has coached World Champion Paratriathletes as well as Ironman World Championship qualifiers. Aaron is an 11 time World Paratriatlhon Champion and has set the World’s fastest time for anyone with a disability at both the Olympic (1:57:24) and Ironman 70.3 distances. (4:09:54).


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