Glycolysis involved in glycolysis. The burning sensation in muscles during hard exercise can be attributed to the release of hydrogen ions during the shift to glucose fermentation from glucose oxidation to carbon dioxide and water, when aerobic metabolism can no longer keep pace with the energy demands of the muscles. These hydrogen ions form a part of lactic acid. The body falls back on this less efficient but faster method of producing ATP under low oxygen conditions. This is thought to have been the primary means of energy production in earlier organisms before oxygen reached high concentrations in the atmosphere between
Oxygen is doubted; a placebo effect is a more likely explanation. Available studies support a performance boost from oxygen enriched mixtures only if it is breathed "during" aerobic exercise. Other recreational uses that do not involve breathing include pyrotechnic applications, such as George Goble's five-second ignition of barbecue grills. Smelting of iron ore into steel consumes 55% of commercially produced oxygen. In this process, is injected through a high-pressure lance into molten iron, which removes sulfur impurities and excess carbon as the respective oxides, and . The reactions are exothermic, so the temperature increases to 1,700 °C. Another 25% of commercially