Free Speed…Reducing Ground Contact Time and Increasing Foot and Ankle Stiffness

Would you like some free speed? If you are a runner or an athlete in practically any sport, does going faster without increasing your metabolic conditioning sound like a good deal?

I hope you said “YES!” to those questions. I’m not kidding when I say that you can go faster, improve your performance and experience, and decrease injury risk at the same time. I imagine you are wondering how this might be possible. Allow me to explain.

When we locomote (walk, jog, run, sprint) our gait cycle has two phases. There is a stance phase when the foot is on the ground and a swing phase when it is in the air. Pretty simple stuff so far. The foot strikes, or makes initial contact with the ground in a supinated, or CLAW position. Then it pronates, or forms a PAW (to varying degrees based on individual differences and velocities) to adapt to the support surface. And then it re-supinates, moving back toward the CLAW position, to enable a strong, rigid push off. This CLAW-PAW-CLAW transition is integral to every stance phase as we move from point A to point B. Or at least it should be. 

In that C-P-C relationship the time the foot is on the ground is known as the ground contact time (GCT). The GCT is the residence time or period in the gait cycle when we are transferring energy into the ground (gravity, bodyweight, muscular force) and then receiving that impulse back (ground reaction force). In the world of The Lifetime Athlete, where science meets common sense, it would make perfectly good sense that, all other things being equal (stride length and rate), the less time we spend on the ground the faster we go. 

This fact is exemplified by every elite athlete in practically every sport. They maximize their mechanical efficiency to have as brief a ground contact time as possible. Elite sprinters generally have GCT’s of .08-.12 sec. This is literally the blink of an eye, with Usain Bolt consistently registering .08 in a 100m dash (once past the first few steps in acceleration). Elite marathoners have GCT’s of about double that of the sprinters, and many recreational runners are spending .3-.4 seconds on the ground with every footplant. Plant is actually a good word here, as they are staying on earth long enough to grow roots. 

For any average runner or athlete (you can define that any way you like), knocking off even a couple hundredths of a second in GCT will yield huge time savings over distance. Let’s say we have a “good” recreational runner whose GCT is about .03 seconds at race pace. Removing .002 seconds from each foot strike, reducing average GCT to .028 sec, will result in a 30-second time reduction for a 22-minute 5k runner, getting him/her to 21:30 with no addition in training mileage or workout intensity. And for a 4-hour marathoner, that same .002 reduction will yield an almost 5-minute speed-up. And this is a very conservative estimate, at 2 hundredths of a second in GCT reduction. The potential for even greater time reduction, and thus speed, certainly exists.

I’m all for training appropriately, and hard on occasion, to build fitness. But shoring up mechanical issues, and improving foot mechanics, is really the place to start. Sure, running fast involves lots of things, and I’ll be going over many of them in future articles, podcasts, videos, and MasterClasses, but reducing GCT is the best place to start.

How exactly does one accomplish this lowering of the GCT? By enhancing the C-P-C functionality in the foot. And this is achieved through the development of stiffness. This is a word that is horrendously misunderstood in fitness circles. We are not talking about a loss of mobility, or a painful creakiness and limitation in our movement patterns. Instead, we are discussing appropriate levels of rigidity in our biomechanical/locomotive system to transfer force. When you are running, cutting, jumping, or dancing, you want to hit the ground with a stiff spring, not a wet noodle. Collapse ain’t cool. And it don’t cut it, Kenny (inside joke). That’s not the frequency, Kenneth (again). 

I dare to say that decreasing GCT and increasing lower limb stiffness is not a cutesy idea or suggestion. It’s pretty much fact and this natural, necessary function in the human beast is well-supported by research. A recent study, published in November 2019 entitled “Humans Optimize Ground Contact Time and Leg Stiffness to Minimize the Metabolic Cost of Running” substantiates the concept.

Elite runners generally self-select the best mechanics to support running economy. Their form is such that energy loss or waste is minimized or eliminated. In fact, across practically all sports, there is very little difference among the upper level performers with regard to fitness and conditioning. But what usually sets the winners, the best of the best, apart from the also-rans, is their mechanics. Champs are always just a little better, smoother, more graceful, and more powerful in how they interact with the ground. You can see it and often even hear it. Elite athletes “pop” off the ground. They don’t use ground contact mechanics that are sleepy-sloppy-slapfoot-slamdown-squishy-wishy-washy.

So how do you increase foot and limb stiffness as you decrease GCT? You use smart training progressions that build muscular strength to maintain isometric contractions against high force. You increase bone density and durability. You improve tendon stiffness which is the secret to elastic rebound and energy return. And you practice, entrain, and ingrain optimal movement patterns. Here’s a sample of how this might look, and how I’ve helped a lot of clients to PR’s:

  • Build basic strength and tissue integrity with squats, lunges, step-ups, etc.
  • Develop isometric holding capacities in sport-specific positions.
  • Create proficiency with hopping, jumping, landing, and bounding skills.
  • Utilize box jumps, depth jumps, and reactive plyometrics.
  • Progress to gait mechanics specific to the sport with drills and cueing.

That’s a very general overview of how I take an athlete through conditioning over several months that prepares the body safely to reduce GCT and improve stiffness/energy transfer. The specifics depend upon the athlete’s training age, abilities, goals, and sport. The cool thing about this kind of work is it really only adds a few minutes to a couple of workouts each week, yet yields a huge return on investment. 

If you’d like to explore how you can get some free speed through these techniques, sign up for the MasterClass on Foot Speed, or Contact me to request a custom class for your team or business. And if you’d like some one-on-one Coaching in this or other areas to help you to your next peak performance, it would be my pleasure to assist you. Stay healthy, stay fit, stay FAST…and stay Hard to Kill! Coach JZ out.

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