20/05/2026
Zone Insight #39: Isometric training should be added to runners gym work
Not the sexiest training method, and not what most runners think about when they hit the gym, but isometric strength training might be one of the simplest additions you can make to your routine to run more efficiently. Swipe across for the full protocol, or read below to understand how it works.
Most runners who add strength work reach for squats, deadlifts, or plyometrics, which all make sense, but there is a quieter option that produces some of the same adaptations at a lower fatigue cost and takes almost no time to implement. You can do it before your first squat or as part of your warm up, and the whole thing takes two minutes. You contract a muscle hard against something that does not move, no range of motion, no complex loading, just sustained maximum effort against an immovable resistance.
Every time your foot hits the ground your tendons act like a spring, absorbing force on landing and returning it on push off, and a stiffer tendon does this more efficiently, meaning less energy wasted. Tendon stiffness and running economy is one of the stronger mechanistic arguments in the endurance physiology literature, and isometric training appears to improve tendon stiffness.
Sustained high effort isometric contractions stimulate increases in collagen fibril number, diameter, and density within the tendon, making it structurally stiffer. That stiffness then cascades into reduced ground contact time and less vertical oscillation with each stride, improving running economy.
The evidence base is still small, with only three controlled studies examining this in endurance runners specifically and all in recreational to amateur populations. 2/3 studies found meaningful improvements in running economy following isometric interventions, and one found greater gains than from plyometric training.
It does not replace your existing strength work but sits cleanly alongside it, two exercises, 10 to 20 reps, 3s ON 3s OFF at maximum effort. Swipe to see the full protocol.
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