Fat metabolism

The body has reserves of fat. The fat stored in various parts of the body is an
important source of energy. Stored fat can be used as a plentiful source of energy. Fat
catabolism has three major sources of energy. The first source of energy is the
triacylglycerols in the muscle fiber (Katch, McArdle, & Katch, 2015). The second source
is circulating triacylglycerols in lipoprotein complexes while the third is adipose tissues.
Adipose tissues are the major suppliers of fatty acid molecules. Adipocytes store and
synthesize triacylglycerol. Adipocytes thus play an important role in fat storage as well as fat
mobilization. When fatty acids enter the bloodstream, they are bound to plasma albumin.
The utilization of fat depends on blood flow in the active tissues (Thomas & Noubani, 2014).
When one is engaging in intense physical activity, more free fatty acid (FFA). FFAs are
either bound with intramuscular proteins or esterify to form intracellular triacylglycerol
(Katch, McArdle, & Katch, 2015). Intermuscular proteins enter the mitochondrion for energy.
In the mitochondrion, the fatty acid molecule transforms to acetyl-CoA. The transformation
happens during oxidation reactions. The respiratory chain helps in oxidizing the hydrogen
released during the catabolism of fatty acids (Katch, McArdle, & Katch, 2015). The
breakdown of fatty acids is associated with oxygen uptake. In instances where glucose is
limited, ketone bodies can be oxidized and used as fuel for the body (Turner, Cooney,
Kraegen, & Bruce, 2014). Fat is also used as a source of energy when physical activities
are intense. It also occurs when one takes a diet that is low in carbohydrates.
Protein Metabolism

Proteins supply the body with energy during long periods of physical activity.
Proteins are important when one is engaging in physical activities that require a high level of
endurance. The first step is the conversion of the amino acids into molecular forms that enter
the pathway for energy release (Katch, McArdle, & Katch, 2015). The conversion involves
the removal of nitrogen from amino acids. The process of deamination where the nitrogen is
removed from the amino acids takes place in the liver. An acceptor acid is sourced from a
donor amino acid to an acceptor acid (Katch, McArdle, & Katch, 2015). When the amino
acid loses its nitrogen-containing amine group, the remaining compound helps in the
generation of energy. In some instances, amino acids are glucogenic and this means that
when they are deaminated, they produce intermediate products for glucose synthesis via
gluconeogenesis. This method is useful during periods of prolonged physical activity.
Carbohydrate Metabolism
The process of carbohydrate metabolism can take place either aerobically or
anaerobically. The implication is that the process can take place with or without oxygen. The
process of carbohydrate metabolism is called glycolysis (Katch, McArdle, & Katch, 2015).
When one is engaging in light and moderate physical activity, carbohydrates provide the
body with the main source of energy. Aerobic glycolysis is relatively slower compared to
anaerobic glycolysis.
Benefits of Different Energy Sources
`It is important to ensure that your body has all the required macronutrients required for
energy. With different sources of energy, you will be able to continue playing soccer and
ensure that your body remains energized. You can thus play for long periods without
being exhausted.

References

Katch, V., McArdle, W., & Katch, F. (2015). Essentials of exercise physiology. (5th ed.).
Retrieved from https://www.vitalsource.com/
Thomas, S. E., & Noubani, F. (Writers). (2014). Cell metabolism and respiration (Links to an
external site.) [Streaming video]. Retrieved from the Films on Demand database.
Turner, N., Cooney, G. J., Kraegen, E. W., & Bruce, C. R. (2014). Fatty acid metabolism,
energy expenditure and insulin resistance in muscle. Journal of
Endocrinology, 220(2), T61-T79.