This painful effect is commonly referred to as cramp. When the body can no longer remove lactic acid as quickly as it is produced (for example during a long-distance race), the acid starts to gather and ultimately prevents energy production and muscle movements. As the intensity of an exercise increases, for example, by fast walking, then jogging, and finally sprinting, more and more lactic acid is produced. In other words, the body monitors the rate of production and does not hamper energy production. No glycogen is needed, and no lactic acid is produced.ĭuring a low-intensity aerobic exercise, such as a moderate jogging or fast walking, lactic acid is slowly produced by glycogen/glucose and removed before it can concentrate. In these cases, existing ATP and creatine phosphate or CP stocks are enough for energy needs. Lactic acid is produced during most types of exercise, not only during anaerobic activity.Īn exception is the kind of explosive activity that involves a single lift during a weightlifting training or a 20-meter sprint running in a football match. Aerobic energy production is therefore about 20 times more efficient and can be maintained for a longer period of time. However, under these conditions, a glucose molecule can generate up to 38 ATP molecules. The energy demand is slower and smaller than in an anaerobic because, it takes longer to transport enough oxygen from the lungs to the muscles, than to use the oxygen to generate ATP. In this system, glucose is completely split into carbon dioxide, water and energy rather than lactic acid. For this reason, no one can run or ride a bike at great speed for a long time.ĭuring aerobic exercise, ATP is produced in the usual way, using oxygen. Lactic acid prevents energy production by creating an acidic environment in the body that ultimately prevents muscle contraction. A high concentration of lactic acid is produced as a byproduct of this rapid glucose disruption. So, this high-speed production of ATP can only be sustained for 90 seconds. To create a large amount of ATP in this way, a large amount of glucose is consumed, causing the glycogen stores in the body to decline rapidly.

Under these conditions, the glucose is only partially broken down and is converted into lactic acid instead of carbon dioxide and water.

However, instead of producing the usual 38 molecules of ATP per molecule of glucose, the body can only make 2 using this anaerobic reaction. Instead it saves time by following different routes which don't require oxygen. To deal with these sudden explosions of power, glucose bypasses the normal energy-generating pathways which use oxygen. Another chemical called phosphocreatine (PC) is required to reform the ATP molecules.Īnaerobic activity, such as sprinting, requires glucose very quickly to cope with sudden and major energy needs. ĪTP is consumed and reproduced repeatedly to generate biological functions such as cell regeneration and muscle building.Įnergy is released as the ATP molecules are cleaved into adenosine diphosphate molecules (ADP).

This chemical substance is stored in the muscle cell and is used to 'fuel' the onset and continuity of muscle contraction. South Georgia & South Sandwich Islands (GBP £)įThe essential element required to produce movement in the human body is ATP (adenosine triphosphate).

Cardiorespiratory endurance definition