What to wear to run in heat, cold and rain

A running body produces a lot of heat, and it starts doing so within a few minutes. Anybody who is comfortable standing still at the start of a run in cold weather is overdressed and will be uncomfortable for the remaining fifty minutes, with nowhere to put the layer they no longer want.

The working rule is to dress as though it were rather warmer than it is — comfortable at the start means too warm at kilometre two. The first few minutes being unpleasant is the correct outcome, not a mistake.

Extremities are the exception to the rule above. Your core will heat up; your hands and ears will not, because blood is being diverted away from them. Gloves and something over the ears are the two items that make cold running tolerable, and they are also small enough to carry once you warm up, which a jacket is not.

Cotton is the material to avoid. It absorbs sweat, holds it against the skin and stops insulating once wet, which in cold conditions turns a comfortable run into a cold one at the point where you slow down. Any synthetic or wool base layer solves this and does not need to be expensive.

The uncomfortable truth about running in rain is that you will get wet either way. A fully waterproof jacket keeps rain out and also keeps a running body’s substantial sweat output in, so at any real effort you end up wet from the inside instead. Nothing on sale entirely resolves this.

In mild rain the usual answer is to accept being wet and wear something that still insulates when it is — a light wind layer over a synthetic base is more comfortable than a waterproof shell. A genuine waterproof earns its place when it is cold as well as wet, when it is windy, or when you are going somewhere that stopping is not a quick option, which is why it is a required item on many off-road events.

The things that ruin a run in the wet:

• Chafing — Wet fabric against skin is far more abrasive than dry. This is what anti-chafe balm is for, and it is applied before rather than after.
• Seams under a pack — Anything with a shoulder strap over it will find every seam, given an hour.
• Wet feet — Unavoidable. Technical socks and shoes that drain are the fix, not attempts at waterproofing.

Heat is the condition where clothing helps least and behaviour helps most. Light-coloured, loose, minimal clothing is better than technical fabric claims, and a hat that shades the face is worth more than most running-specific garments.

The substantive adjustments in heat are not clothing at all: running earlier or later, choosing shaded routes, carrying water on anything long, and accepting that the same effort produces a slower pace. That last one catches people out repeatedly — trying to hold a normal pace in unusual heat is how a routine run becomes a bad experience.