Theoretically, anaerobic activity is the type of movement or exercise used in the ‘fight’ response. Anaerobic exercise (e.g. resistance training, sprint training) increases and help maintain lean body mass, which is the most metabolically active tissue in the body.
Anaerobic energy systems are of two major types. The immediate energy system is used for high-intensity activities that last less than 30 seconds, such as running the 100-meter dash or lifting heavy weights. Here, the muscles use ATP and creatine phosphate (CP) supplies at are already stored in the muscles, which last only 1 to 10 seconds.
The lactic acid system is a second source of energy for anaerobic activities. This system generates ATP for high-intensity activities lasting from 30 seconds to 3 minutes, such as the 400-meter or 800 meter run, which continues after the ATP-CP system for approximately 5 to 6 minutes.
Lactic acid has an incredibly fatiguing effect on muscle contraction. Because the full redistribution of blood takes 4 to 6 minutes, depending on the condition of the individual, initial oxygen supply is minimal at best.