Clothing for running below freezing

Short answer: Dress as if it were five degrees warmer than it actually is. The first ten minutes should feel slightly cold, otherwise you are wearing too much for the rest of the run.

Your body warms itself up in ten minutes

After ten minutes of running, the body is five to ten degrees warmer than at the start. That is why you should feel a little cold at the door. Dress warm from the first step and you sweat needlessly the whole way, and that damp layer cools down fast the moment your pace drops. See bamboo t-shirts for men.

The base layer should not be thick

A thick base layer traps moisture and cools you down the moment you stop. A thin layer close to the skin moves sweat away instead of holding onto it, so you stay dry through the run and avoid that cold feeling once you slow down. See bamboo underwear for men.

Hands and head freeze first

The extremities freeze while the core is still warm from the effort. Fingers and ears get less blood flow than the torso, so they feel the cold first and hardest, even when the rest of your body still feels warm during the run.

Change the moment you get home

Damp clothing in freezing air cools the body very fast once the run is over. The moment you stop moving, body temperature drops, and a wet layer makes that much worse. Change into dry clothes before you sit down. See bamboo socks for men.

Layers beat one thick piece

Three thin layers warm better than one thick sweater, because the air trapped between layers insulates better than a single thick piece of fabric. It also lets you remove a layer along the way if you get too warm. See bamboo clothing for men.

Wind steals more heat than cold

A cold, still day often feels easier to run in than a milder, windy one. Wind cuts through fabric and carries away the warm air you have built up close to the skin, so a windproof outer layer often matters more than extra layers underneath.

Breathability prevents overheating

Even in freezing weather you can overheat if the fabric does not let heat escape. A breathable material lets excess warmth and moisture out, so you avoid ending up soaked through after only the first couple of kilometers.

Feet and face need extra care

Feet stand still inside shoes and move less than the rest of the body, so they cool down faster. Thin wool or bamboo socks hold heat better than thick cotton ones, because they carry moisture away from the skin as you run.

Plan the route around the wind

Run into the wind on the way out and with it on the way home. That way you avoid being soaked in sweat and facing headwind at the same time, which is the combination that really sets in the cold on the way back.