The Triathlete Blueprint Newsletter #102-Ground Contact Time: The Metric That Can Make or Break Your Run

Read time: 4min.

By Coach Yan Busset

Ground Contact Time: The Missing Link in Your Run Efficiency

One metric that often flies under the radar is ground contact time, or GCT. Throughout this article, we’ll stick with GCT to keep it simple.

Triathletes tend to carry over their cycling habits into their running. Just like they push hard on the pedals, they often hit the ground with too much force when they run. What’s missing is that lightness of the foot — what we call in French “avoir du pied” — meaning reactivity and finesse in your stride. After spending hours in the saddle, it’s natural for the legs to feel heavy, but developing a more responsive and efficient stride makes a big difference once you get off the bike.

To picture what good GCT and avoir du pied really mean, imagine yourself running barefoot on ashes or over eggs without cracking them. That’s the mindset: light, controlled, and precise with every step.

What is GCT and How to Measure It

GCT is simply the amount of time your foot stays on the ground with each step. The less time you spend on the ground, the quicker and more efficient your running becomes.

Nowadays, tracking your GCT is straightforward. Devices like Garmin, Apple Watch, Stryd pods, and other smart sensors give you this data directly. It’s a really useful way to monitor your progress and fine-tune your running efficiency.

One thing to keep in mind: as you run faster, your GCT naturally goes down. So, to track real improvement, always compare runs at the same pace. In short, compare apples with apples.

To give you a sense of where you stand, here’s a handy reference:

Below 240 ms: sharp and efficient
241 to 270 ms: solid, but room to progress
271 to 300 ms: needs targeted work
Over 300 ms: plenty of room for improvement

Most beginners fall in the 270 to 300 ms range. With smart, consistent training, you can definitely move below that and feel the difference.

Why Does GCT Matter?

GCT is a great indicator of how efficiently you’re running. If your foot stays too long on the ground, you lose momentum and waste energy. In triathlon, where fatigue builds up fast, every bit of efficiency matters. Working on your GCT can save you valuable energy over the run leg.

By reducing your GCT, you build a lighter, snappier stride. When you’re already carrying fatigue from the swim and bike, that efficiency really pays off. One good additional benefit of lowering your GCT is to lower also your injury risk, as your GCT decrease, the peak impact force that can cause damages, diminish too.

What Influences Ground Contact Time?

Several factors come into play with GCT.

Power and force application. The faster and more explosively you push off the ground, the shorter your GCT becomes.
Leg stiffness at footstrike. A stiffer leg works like a spring, storing and releasing energy effectively.
Running form and posture. Good posture, strong core, and an aligned upper body let your legs do their job efficiently under you.
Foot placement at contact. Aim to land your foot under your centre of gravity to avoid overstriding and braking.

How to Reduce Your GCT

Here’s how you can start bringing your GCT down.

Short interval workouts. Fast intervals train your body to react quicker and move more efficiently, sharpening your stride.
Plyometric training. box jumps, explosive movements, and especially rope skipping are great for building quick force application. They directly help reduce GCT and improve leg stiffness.
Running drills. Drills like skipping, fast-feet work, and coordination exercises develop agility and encourage a lighter step.
Cadence drills. Focusing on cadence helps you naturally increase your step rate. Try boosting your cadence by around 5 to 10 percent. At the same pace, this lowers the impact of each stride, shortens your GCT, and smooths out your running.
General strength training. Building strength in your core and legs supports better posture and helps you hold efficient mechanics, especially when fatigue sets in.
Transition work, strides right off the bike. Triathlon is unique because you have to switch fast from the heavy pedal smash fest of the bike to a lighter, quicker running rhythm. Practicing strides straight off the bike trains your body to make this switch sooner on race day.

Conclusion

GCT is more than just a number on your watch. It’s a direct insight into how well you’re running. For triathletes, it can really make a difference. Don’t get caught up in chasing perfect numbers, but train with purpose, apply simple, effective strategies, and let the improvements build up over time.

Track it, work on it, and you’ll feel the benefits where it counts most: on race day.

And remember, every step counts.

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