Changes

Running in the heat is much harder than running in cooler temperatures, reducing performance and creating serious health risks. Moderate exercise in mild temperatures, such as 60f/15c, will reduce performance, but the perception is likely to be fatigue rather than overheating. Without preparation More extreme exercise or temperatures can create the risk of heat illnesses which can be punishing dangerous. =Heat and Fatigue=It is generally accepted that exercise at a constant effort will be voluntarily terminated once the core body temperature reaches about 40c/104f<ref name="Tucker-2008"/>. However, if subjects are allowed to vary their pace freely, they will preemptively reduce their exercise intensity to prevent their core temperature form reaching the critical point<ref name="Tucker-2008"/>. One mechanism for this reduction is that fewer muscle fibers are recruited in hot conditions, even before the core body temperature starts to rise<ref name="Tucker-2004"/>. Elevated core temperature reduces the voluntary maximum force generated, though it is unimpaired when electrical stimulation is used, indicating the central nervous system is responsible<ref name="Nybo-2008"/> . When exercising at a constant [[Rating of Perceived Exertion]], subjects steadily reduced their power output at 59f/15c, 77f/25c or 95f/35c even dangerousthough their perception of their temperature comfort remained constant<ref name="Tucker2006"/>.==Mechanisms==Exercise in the heat burns more carbohydrate than in cool conditions<ref name="Mündel-2008"/> . The most important step However, it is not clear to realize that running me if this is because of a direct change in the use of carbohydrate, or if the hot conditions reduce [[VO2max|V̇O₂max]] and therefore the exercise intensity is effectively increased. Exercise in the heat requires just as much care as running also burns more muscle protein<ref name="Snow-1993"/><ref name="Marino-2001"/>, and the waste products from this protein metabolism could result in mental fatigue due to a rise in extreme cold[http://en.wikipedia.org/wiki/Gamma-Aminobutyric_acid GABA]<ref name="Mündel-2008"/>. ==Hyperthermia - Heat can kill==Running in the heat can kill, as the bodies body's protective mechanisms that normally cause us to slow down can be ineffective. There are a number of risk factors for serious heat injury* # Being overweight, as fat can act as an insulator.* # Being untrained, as fitness gives some heat adaptation over the unfit, and also teaches the mind some of the danger signs of heat problems.* # Lack of heat acclimatization, which both as this acclimatization gives some protection from the heat and also teaches the mind to adjust the intensity based on heat. * # Thinking you can run faster than you can in the conditions. * # Having suffered from heat illness before.* # Ignoring warning signs (see below).==Staying Alive in the Heat - The Warning Signs==

==Tips for Running in the Heat==

* Even holding some ice in your hand, or holding a cold water bottle can [http:help<ref name="Hsu-2005"//www.ncbi.nlm.nih.gov/pubmed/15855685 help]>.

 ==See Also==