This produces water and carbon dioxide

This produces water and carbon dioxide. The process uses oxygen. Some of the oxygen required during aerobic respiration in the red muscles is generated from oxygenated myoglobin. Myoglobin refers to a protein that is located in the muscles and used for storing oxygen. Similar to haemoglobin, myoglobin forms a loose link with oxygen. This occurs when there is plenty oxygen supplies. The combination is held until oxygen demands escalate. Eventually, the muscles have an internal supply for oxygen.

In situations where the skeletal muscles are involved in laborious muscular activity, for instance when lifting heavy objects or during intensive exercise, there are huge energy demands (Purves, Augustine & Fitzpatrick et al, 2004). During such cases, the oxygen attached to myoglobin is utilized quickly. Considering that it is impossible to get adequate oxygen into the tissues as quickly as possible, the muscles acquire additional energy from anaerobic procedures. This calls for lactic acid production, which is accomplished via fermentation.

This results to oxygen debt. A small amount of the lactic acid collects in the muscles. However, the rest gets into the muscle capillaries and is taken to the liver. The blood acts as the medium through which lactic acid is carried. After a person engages in laborious exercise, he experiences a period of panting and hard breathing, which is useful for supplying the liver with adequate amounts of oxygen. This oxygen is vital for aerobic respiration and assists in covering for the oxygen debt. While in the liver, pyruvic acid is formed from lactic acid. Oxidation of pyruvic acid forms water and carbon dioxide. Moreover, ATP energy uses the extra lactic acid to manufacture glycogen and glucose.

It is worth pointing out that lactic acid should be removed from the muscle fibres straightaway. Otherwise, extreme damages can be experienced. In this regard, a resting period is extremely important after a person experiences strenuous exercise. There is need for an uninterrupted blood flow in the muscles, which is useful for getting rid of lactic acid. Lactic acid should never be allowed to accrue in the muscles. This prevents sore muscles and guards the muscle proteins.

In this regard, endurance- training strategies designed for athletes aim at ensuring that more oxygen is available to the muscles. This measure promotes aerobic metabolism. During instances of endurance- training programs, there is an increase of mitochondria in the muscle fibres. In addition, there is an increase in myoglobin and novel blood capillaries. Consequently, blood circulation increases in the muscles. Athletes who have been trained have greater capabilities for undergoing through laborious exercise because there is increased accumulation and manufacture of lactic acid.

Usually, a spasm or cramp comes with abrupt pain. The pain is as a result of the pain receptor stimulators, which functions mechanically in the muscle (Fitzgerald, 1996). Furthermore, the pain may be as a result of compression to the blood vessels, which interrupts with oxygen delivery to the muscle fibres. It is worth noting that a majority of the muscle cramps is as a result of calcium deficiency, which is more common in pregnant women. Calcium is not only used for forming calcium phosphate, which composes dentin, enamel, and hardened bone. Calcium plays a vital role during muscle contraction.