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Created page with "This page gives details of the mathematical model of the heat generated and lost while running. =Basic Heat Calculation= The basic heat calculation is from # Heat produced from..."
This page gives details of the mathematical model of the heat generated and lost while running.
=Basic Heat Calculation=
The basic heat calculation is from
# Heat produced from running. This is dependent mainly on your weight.
# Heat lost (or gained) from convection. This is mostly dependent on your surface area (calculated from weight and height), and the air temperature.
# Heat lost (or gained) from radiation. This is mostly dependent on your surface area and the air temperature.
# Heat lost from evaporation of sweat. This is mostly dependent on your surface area, the air temperature and humidity.
=Important caveats=
These calculations make lots of assumptions.
* Your running efficiency may be different to the average. A higher efficiency will produce less heat at a given pace, a lower efficiency will produce more heat.
* The only air movement is assumed to be from running through still air.
** Any wind can make a significant difference, with a headwind or crosswind cooling your off. A tailwind less than twice your running pace will reduce your cooling; it takes a tailwind of at least twice your running pace to cool you off more than still air, but of course a tailwind will reduce the energy required to run.
* The calculations assume negligible clothing. If you are wearing more than the absolute minimum clothing, this will impair your ability to cool off.
* It is possible to actively cool off with ice, which will allow you to tolerate higher temperatures.
* Any direct sun will increase the heat stress and dark clothing will make this worse.
=Advanced notes on calculations=
These notes are for those with an interest in the underlying details.
* There are multiple formulas for calculating water vapor pressure which produce slightly different results.
* The calculation of skin temperature is not straightforward. The calculator uses a combination of Neilson's approach and the Mehnert formula.
* The various formulas for calculating the surface area of the skin appear to give similar results.
=References=
This calculator is based on [http://www.ncbi.nlm.nih.gov/pubmed/8784753 Olympics in Atlanta: a fight against physics] and [http://www.ncbi.nlm.nih.gov/pubmed/10048634 Advantages of a smaller bodymass in humans when distance-running in warm, humid conditions]
=See Also=
* [[Running in the Heat]]
* [[Perceived Temperature For Runners]] (An experimental chart)
* [[Heat Acclimation Training]]
* [[Impact of Heat on Marathon Performance]]
* [[VDOT Calculator]] which adjusts for heat
=Basic Heat Calculation=
The basic heat calculation is from
# Heat produced from running. This is dependent mainly on your weight.
# Heat lost (or gained) from convection. This is mostly dependent on your surface area (calculated from weight and height), and the air temperature.
# Heat lost (or gained) from radiation. This is mostly dependent on your surface area and the air temperature.
# Heat lost from evaporation of sweat. This is mostly dependent on your surface area, the air temperature and humidity.
=Important caveats=
These calculations make lots of assumptions.
* Your running efficiency may be different to the average. A higher efficiency will produce less heat at a given pace, a lower efficiency will produce more heat.
* The only air movement is assumed to be from running through still air.
** Any wind can make a significant difference, with a headwind or crosswind cooling your off. A tailwind less than twice your running pace will reduce your cooling; it takes a tailwind of at least twice your running pace to cool you off more than still air, but of course a tailwind will reduce the energy required to run.
* The calculations assume negligible clothing. If you are wearing more than the absolute minimum clothing, this will impair your ability to cool off.
* It is possible to actively cool off with ice, which will allow you to tolerate higher temperatures.
* Any direct sun will increase the heat stress and dark clothing will make this worse.
=Advanced notes on calculations=
These notes are for those with an interest in the underlying details.
* There are multiple formulas for calculating water vapor pressure which produce slightly different results.
* The calculation of skin temperature is not straightforward. The calculator uses a combination of Neilson's approach and the Mehnert formula.
* The various formulas for calculating the surface area of the skin appear to give similar results.
=References=
This calculator is based on [http://www.ncbi.nlm.nih.gov/pubmed/8784753 Olympics in Atlanta: a fight against physics] and [http://www.ncbi.nlm.nih.gov/pubmed/10048634 Advantages of a smaller bodymass in humans when distance-running in warm, humid conditions]
=See Also=
* [[Running in the Heat]]
* [[Perceived Temperature For Runners]] (An experimental chart)
* [[Heat Acclimation Training]]
* [[Impact of Heat on Marathon Performance]]
* [[VDOT Calculator]] which adjusts for heat
