Training outdoors when the sun is high

Short answer: Cover the skin rather than exposing it. A thin, loose layer protects against sun and cools better than bare skin, because sweat evaporates from the fabric instead.

Loose fabric cools better than bare skin

The air between fabric and skin carries the heat away. Bare skin in the sun absorbs it directly from the rays, while a loose layer creates a pocket of air that leads heat away from the body instead of letting it build up on the surface. See bamboo t-shirts for men.

Long sleeves protect against sun

A thin layer over the arms gives shade the whole way, so your arms do not end up more sunburned than the rest of your body. A loose, thin material does not block airflow, so you will not feel too warm under it in the heat. See bamboo clothing for men.

Sweat needs to be able to evaporate

If the fabric sticks to the skin, evaporation stops and you get warmer. Sweat is the body's natural cooling system, but it only works if there is space between skin and fabric for air to circulate and carry the moisture away. See bamboo underwear for men.

Feet end up the warmest

The foot inside a closed shoe is the warmest part of the body, because it does not get the same airflow as the rest of you. Thin socks in a breathable material make a noticeable difference on long workouts in the heat. See bamboo socks for men.

Light colors reflect more sun

Dark colors absorb sunlight and become warmer to wear than light ones. Choose light shades on the hottest days, so the clothing itself does not add to the heat you already need to get rid of during the workout.

Drink before you feel thirsty

Thirst is already a sign of mild dehydration, so drink regularly throughout the session instead of waiting until you notice it. That makes it easier for the body to hold a stable temperature while the clothing does the rest of the work.

Train during the coolest hours

Morning and evening are noticeably cooler than the middle of the day, even in the same season. Move your workout there and you cut the strain significantly, so the clothing has to work less hard to keep you comfortable along the way.

Cotton holds onto moisture longer

Cotton soaks up sweat but dries slowly, so the fabric stays heavy and wet for the rest of the session. A fast-drying material like bamboo viscose feels lighter and less clammy, even after an hour in the sun.

Shade on the route makes a difference

Choose a route with trees or buildings that give shade for part of the way, rather than fully open stretches. Combined with the right clothing, you feel a clear difference in how hard the heat pushes on you along the way.