Morning Team,
It would be fair to assume muscular contraction – that being - in our feet, Achilles tendons, calves, quads, hamstrings &amp; hips - is considered to be the main force moving and accelerating a runner forward - while on support (that being – the most balanced mid-phase posture in the run stride).

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This could be contradicted, if we assume that gravity is in actual fact the main moving and accelerating force in running. The role of muscles then is reduced to simply regulating the direction of gravity's action on the body, while having a connection of support and being in the state of unstable balance (the mid-phase).

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The movement of the runner on support, after it passes the mid-phase/stance is nothing else, but tipping the body, rotating around the point of support (foot &amp; ankle). Meaning – stall tall – hold your trunk strongly enough to maintain a perfectly balanced spinal position – and then simply lean forward – ever slightly leading with your hips, and using your ankles as your pivot.

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While you’re falling (again holding your most upright balanced position), which should pick up pace the further you fall, I suspect at some point you’ll consider lifting one foot (your base of support) off the deck to save face planting.

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The forward displacement of the runner's body is determined by the geometry of the falling body on support – not driving hard into the surface – pushing yourself off support. The horizontal movement (acceleration) of the body is a function of the angle of deviation of the body from its vertical position. So basically, if you wish to run faster, take your lean/ fall to a more acute angle – before your lift up your base of support to catch this fall. On support the muscles do not work to push the body forward, they work to transform the gravity-force downward movement into a horizontal one.

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On your next run – think of holding your posture nice and tall – and visualise falling forward (holding your perfect posture) – while minimising muscles contractions. Obviously remember to lightly but quickly lift your supporting foot off the surface.

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The less effort, the greater the speed, the better!