The reasoning builds itself. A cushioned sole compresses under a heavy deadlift, foam absorbing force that should reach the floor — switch to flat shoes and every newton goes straight into the platform. You didn’t borrow this from a forum — you worked the physics out yourself, and every link in the chain holds.
When the logic is that clean, the only question left is whether anyone actually measured it.
Does wearing flat shoes make you stronger at deadlifts
Flat shoes do not increase the force a lifter produces during a deadlift. In thirty trained lifters, peak ground reaction force was identical in shoes and barefoot. Removing sole height shortens the bar’s path by about three centimeters, reducing total mechanical work per rep. The lift becomes more efficient, not stronger.
— Valenzuela et al. 2021 · Sports (Basel) · n=30
Force plates bolted under a deadlift platform gave thirty trained lifters exactly that answer — conventional and sumo pulls, shoes on and barefoot, at seventy percent of their max. The displacement numbers landed right where the physics predicted. The force numbers did not.
Peak ground reaction force was identical regardless of footwear. Shoes registered 989.7 newtons. Barefoot: 993.9 newtons. The difference fell within the instruments’ margin of error. Peak bar velocity matched too — same speed, both deadlift styles, both conditions. Every newton a lifter pushed into the ground arrived there whether a sole was underneath or not.
Every centimeter of sole between your foot and the floor was height the bar had to travel through.
Removing the shoe shortened bar displacement by roughly three centimeters — the sole’s thickness converted into range of motion the barbell no longer needed to cover. Same force over a shorter path meant about four percent less mechanical work per rep and a fraction of a second off each pull. The flat shoe didn’t amplify your pull. It shortened the road.
The distinction sits exactly where your physics split: flat shoes make the deadlift more efficient, not stronger. If the goal is the heaviest single you can lock out, less range of motion is a genuine advantage — the bar has less distance to clear. If the goal is building training volume, a thicker sole forces more mechanical work across a session without adding a plate. Both are legitimate goals. Neither involves the shoe adding force.
These numbers carry a boundary: the study tested standard running shoes with a twenty-nine-millimeter heel against bare feet. Flat-soled lifting shoes sit closer to barefoot — the displacement gap would shrink, and the efficiency difference with it. The underlying physics holds. What was measured is likely a larger version of what flat-soled shoes would produce.
Your engineering identified the right variable — shorter bar path, less distance to cover. The conclusion just landed on the wrong outcome. Sole height changes the geometry of the pull, not the engine driving it. How you position your feet under a loaded bar matters for what those muscles actually do, and the answer turns on joint angles, not shoe rubber.