Find Free Speed & Reduce Injury via Ground Contact Time
Ground contact time (GCT) is one of the most overlooked running metrics. And yet, focusing on this metric can help increase your speed significantly and reduce your exposure to injury. Whether you’re new to this term or not, keep reading to find out more about what it is, why you should care, and what you can do to improve it once we have you caring about it!
What is it?
Simply put, GCT is the amount of time your foot spends in contact with the ground, measured in milliseconds per step.
Why should I care?
You should care because you are only moving forward when not in contact with the ground[1]. Simply put, the less time you’re spending on the ground, the more time you’re spending in the air, moving forward.
Secondly, there is a greater metabolic cost to being in contact with the ground; therefore, your running economy will improve the lower you can get this number.
Further, Zombro[2] refers to it as “free speed”. We confirmed this statement with our own testing at The Run Lounge. One runner reduced his ground contact time by 10 milliseconds, reducing his 5k predicted time by nearly 30s. Another runner saw a predicted savings of almost a minute in her half marathon time. Now we’ve got your attention!
Also, GCT asymmetry is an indication of potential injury[3]. If your ground contact time is imbalanced, it causes one side to work harder to make up for the other side, reducing running economy and exposing yourself to injury.
How can I improve it?
GCT has many influences including power, leg spring stiffness, hip drop, and where your foot is striking the ground. Here are some tips on how to improve it:
Increase power and leg spring stiffness with strides, plyometrics and resisted running. Increased stiffness helps us utilize the energy upon contact with the ground to push us forward rather than absorb it (think slinky versus spring). And power allows us to cover more ground with each stride.
Decrease your hip drop when running by performing targeted exercises to glutes as well as activating your glutes before you run. The more our hips drop upon foot strike, the more time we are spending on the ground, stabilizing before toeing off[4].
Increase your cadence if you have a naturally low stride rate (less than 170 spm). Low cadence often equals overstriding – i.e.: striking the ground ahead of your centre of mass. This will increase your GCT as you spend more time braking with each step.
Lastly, carbon shoes[5]! We all love them, but why? The carbon plate is essentially assisting us to have a greater spring system and spend less time on the ground. Ok, so maybe this part isn’t so free…
Visit The Run Lounge to book a gait analysis. We can help you identify if you need to work on improving your GCT and where you should focus your efforts for progress. Further, we can help you pick your race day shoe that makes you the most efficient version of yourself. Because, who doesn’t like more speed?
By Melissa Paauwe, Founder of We Run the World Coaching, Inc & The Run Lounge
[1] Fitzgerald, Matt. “Ground Contact Time and Running Performance.” TrainingPeaks, 7 Dec. 2023, www.trainingpeaks.com/blog/ground-contact-time-and-running-performance/.
[2] Zombro, John. “Free Speed...Reducing Ground Contact Time and Increasing Foot and Ankle Stiffness.” The Lifetime Athlete, 24 May 2020, thelifetimeathlete.com/2020/05/23/reduced-ground-contact-time/.
[3] Simonsen, Lars-Christian. “What Is Ground Contact Time Imbalance, and How Can You Improve It?” Run161, 3 Aug. 2023, run161.com/running-training/understanding-ground-contact-time-imbalance-while-running/.
[4] Feet, Geeks on. “Perfect Your Hip Mechanics.” Geeks on Feet, 11 June 2021, geeksonfeet.com/run/pelvicdrop/#:~:text=Performance%20Implications,key%20to%20a%20strong%20stride.
[5] Saha, Sirshendu. “Carbon Plates in Running Shoes: Advantages, Disadvantages, and Their Impact on Biomechanics (1/3).” LinkedIn, 14 Sept. 2023, www.linkedin.com/pulse/carbon-plates-running-shoes-advantages-disadvantages-impact-saha/.
