More calories are burned in warm weather than in cold weather.
- Exercising at 75% of capacity, the average heat loss from the body may range from 900- 1500 calories per hour. An additional 100 - 150 calories may be gained from the sun.
- The body heat is transferred from the warm muscle to the blood and then to the skin where it is dissipated to them by evaporation, radiation or convection.
On a hot dry day at rest;
- 55% of heat loss is by radiation and convection
- 45% by sweat evaporation
- During exercise sweat evaporation becomes by far the major avenue of heat loss, accounting for 98 percent. For every liter of sweat evaporated on the skin, close to 600 calories are given off.
For example, if an athlete sweats 1.8 liters / hour, 1000 calories of heat are removed from the body.
That is not to say that exercise in the cold weather is not beneficial. Certainly any exercise is the best thing for your health. Exercise in hot and humid weather can be dangerous, so pace yourself and keep hydrated.