If we're honest with ourselves, running form can get…a little overcomplicated.
We hear about cadence, and stride length, and stride intervals and stride-to-stride variability between fatigued and non-fatigued states and…
Deep breathe.
Spoiler: Even as a movement professional, it gets a little overwhelming.
But what's on most runner's mind's is this:
How do I find this perfect stride so I don't over-stride and get injured? "
It's a fantastic question!
And the evidence has an answer, but it's not the one you expect.
You ready to dive in?
What is stride length and why does it matter
It's best to start with basics.
Stride length is simply how long is your running step.
And to avoid overstriding, you typically look for it to be equal on both sides and for your leading leg to land within your base of support.
(see? Things are already getting….nebulous).
Basically, you want that leading leg to "catch" you instead of reaching out in front of you. You want to fall from your stance leg onto your leading leg rather than trying to pull the ground towards you.
Hang in there with me, this gets much better.
What impacts or changes your stride length?
Age, height, history of injury, fatigue levels, and your brain.
(you didn't see that last one, did you? But it's true)
Wait, so how does mine brain controls my stride length?
Think of it this way…
muscles + brain and nerves = neuromuscular system
Being able to control this neuromuscular system = neuromotor control
Having neuromotor control means you can pick up a glass of water and drink from it.
Or in our case as runners, means you can go for a run. (Still having a hard time with this? Consider Kara Goucher's recent news.)
What does this mean for you?
Some of aspects that impact stride length you can control; some, not so much.
You can't really control your age or your past history of injury.
Your weight you can control up to a certain point, but it doesn't change rapidly.
But something you're going to encounter every run and that will change with every step: fatigue levels and it's impact on neuromotor control.
What does this have to do with stride length?
I'm so glad you asked.
*Enter our recent research article*
Stride-to-stride variability and complexity between novice and experienced runners during a prolonged run at anaerobic threshold speed by Shiwei Mo, Daniel H.K. Chow.
If you were distill Chow and his team's entire article to one sentence it would be:
"These findings provided insights into how the motor control system adapts to progression of fatigue and evidences that long-term training enhances motor control. Although both experienced runners and novice runners R could regulate gait complexity to maintain anearobic threshold speed throughout the prolonged run, experienced runners also regulated stride interval variability to achieve the goal."
Want to break that down together and this means for YOU?
Let's go.
Chow starts with something that you will almost always see in your training plan: everyone's favorite tempo runs (anaerobic or lactate threshold).
"Running speed at anaerobic levels…has been regarded as one of the best physiological predictors of performance. Runners are recommended to be trained at or slightly above anaerobic threshold speed for effective anaerobic improvement and performance enhancement [15]. However, running at anaerobic threshold speed may result in accelerated fatigue due to a nonlinear steep increase in ventilation, blood lactate accumulation and carbon dioxide production."
Meaning, running that tempo pace is not only hard, but can wear you down due to a build up of waste products that your body isn't able to metabolize and get rid of, etc etc. What that translates to physically is: your body gets tired.
And it's a lot harder to run with good running form and perfect strides when you're tired.
Your stride is more prone to change from step to step. In reality, it's much more preferred if your strides are consistent in order to reduce risk of injury. When they're inconsistent, there exists the possibility for more over-striding or just running like a wet noodle. You're all over the place.
With all that being said…
Chow and his team did find that some variability exists within the individual's own stride length and other characteristics, specifically at the beginning of their tested run. This is normal! And frankly…good news for you and me.
What they found was that it essentially takes time to find your rhythm, pace, "find your stride", however you want to say it. It takes a little bit of time before you find that groove or that zone and then….you settle in and just run.
"…at the beginning, compared to experienced runners, novice runners spent a longer duration to adapt to the treadmill run…"
But what was more interesting was this:
"Alpha was larger at the initial adaptation stage due to highly controlled running movements, and reduced with increased flexibility of the locomotor control system in the middle stable stage. At the end fatigue stage, alpha depended on increased needs for controlling running movements and/or adjusting alterations in kinematics (i.e. reduced joint range of motion; less competent in foot and leg landing positioning) and increased antagonist muscle activation."
Breaking this down and looking at the results of the study, Chow was able to state the longer you run at that tempo pace, at anaerobic threshold pace, the more fatigued you become and the more "flexibility" or variability" is introduced to your stride.
You get tired; your form starts to suffer.
Makes sense right?
The normal solution to this problem: well, just lift more and get stronger and then your form won't break down.
Slooooowwww down a second there.
Strength work is not the ONLY answer here.
Chow has something else to say.
"Regarding effects of a prolonged run on stride interval variability at anaerobic speed, experienced runners and novice runners exhibited different trends.
Novice runners displayed larger variability but maintained relatively constant [strides] throughout the run. For experienced runners…variability [of stride length] decreased initially, then maintained in the middle [of the run] and increased at the end. Experienced runners might have employed a more adaptive strategy during the prolonged run at anaerobic threshold speed, i.e. trying various strategies for determining an optimal one, thereby inducing a relatively larger variability at the exploration period [of the run]; maintaining the optimal strategy in the middle stage, hence variability reduced; and at the end of the run, variability increased due to fatigue.
Overall, compared to novice runners, experienced runners could regulate stride variability to adapt to progression of fatigue during a prolonged run."
Our question:
WHY?
WHY could experience runners regular their stride better during fatigue compared to novice runners?
Let's go back the beginning….
Neuromotor control.
The ability of your brain and body to communicate and control your physical movement.
What Chow found is at the heart of physical therapy and now….at the heart of running.
What he found was that the more you run, the more you practice, the better your form gets.
Yes, you still need to do your mobility work and strength work, and those will help your form, but a lot of issues with stride length, come down to you, the runner, being aware of your body.
It's a balancing act.
Because on one hand, you are being cognizant of how each leg extends, where each foot falls, and where the rest of your body is all at the same time.
On the other hand, you just flow.
You observe your body moving, but you also switch off your brain and just run.
I know, I know…I promised you the perfect stride length.
Here it is.
Based on the evidence we've looked at today, we can conclude that your running form is dynamic, changing, and unique to you. There is always going to be some variability, some small changes in your stride because you're not a machine. And, it might actually change over your running career.
There no such thing as the perfect stride length.
There is technically a most efficient way to run:
Upright tall posture
Short steps
Arm swing close to your body etc.
And those are all important.
In the end, those are postural cues and tools that help you achieve YOUR perfect stride.
But in the end, you only it find by running.
And practicing.
And doing your mobility, strength, speed work, and cross training.
Because with all of those, you ARE honing that oh-so-important neuromotor control that the pro's have. It's through neuromotor control that the elites make running look so effortless and easy. It's by practicing good form, paying attention to how your body feels at all paces and using the postural cues that work for YOU, that help you find not only your preferred stride length, but in the end, your most efficient running form.
So keep running, running fit fam.
And celebrate each run no matter how hard it is.
Because even if your Garmin says it was "unproductive", you know otherwise.
You know you took up the challenge of fine tuning your body-mind connection and finding your flow.
Until next time, Run Strong and Dare to Train Differently,
Dr. Marie Whitt //@dr.whitt.fit