Shaving Seconds

Competitive swimmers shave their bodies before major races — not superstition, but physics. Removing hair smooths the boundary layer next to the skin, trimming friction drag slightly and improving the swimmer's feel for the water.

Beyond the suit and cap, every other surface is tuned too: goggles are made to sit flush against the face so they add no frontal resistance, and even the seams are placed to keep water flowing cleanly. These gains are tiny on their own, but they stack. A single percent of drag reduction can separate gold from fourth place.