Metabolism: How It Is Related to Fitness and Age?

Metabolism is defined as the set of chemical reactions involved in sustaining the living state of the organism and the cells. It is an enzyme-catalyzed reaction which enables the organisms to reproduce and grow, sustain their structures, as well as respond to the environment.   It is divided in two categories: catabolism and anabolism. Catabolism refers to the breaking down of the organic matter  to harvest energy through cellular respiration and anabolism, which  refers to the synthesis of the needed compounds of the cells such as nucleic acids and proteins.

Metabolism is closely related to nutrition and the availability of nutrients. Bio-energetics describes the metabolic or biochemical pathways in which the cell obtains energy and the formation of energy is one of the essential components of metabolism.

The chemical reactions of metabolism are arranged into metabolic pathways, wherein a chemical is changed into another chemical through a sequence of enzymes. Enzymes are important in metabolism, since they enable organisms to initiate reactions that need energy, by coupling them to reactions which release energy. Enzymes serve as catalyst, which allow reactions to occur in rapid phase as well as regulating metabolic pathways due to changes in the environment of the cells.

The term metabolism also refers to the burning of calories to provide energy needed by your body. The three ways that can burn calories include:

1. The resting metabolic rate (RMR). This is the 75% of the burned energy daily. RMR is the calories burned during rest.
2. The thermic effect of food (TEF): This refers to the over 10% of the used energy every day.
3. The physical activity energy expenditure (PAEE): This accounts to the burned energy while doing any activities or while working out.

The PAEE is affected by your activity every day. The more fitness activity you do, the more calories your burned. Increasing the calories you burned through PAEE is one way of speeding up your fitness. If you want to speed up your metabolism, you must do fitness activities that drain glucose instead of fatty acids. Any high-intensity workout will also increase metabolism for a longer time after doing fitness activities.

Does Metabolism Decrease with Age?

The gain of weight as we age is due to the decrease in the calories burned by our body. Low level of physically fitness activity plays an important role in the decreased in the expenditure of energy as well as decline in the metabolic rate due to age. Basal metabolic rate, which makes up 50-70% of TEE, decreases to 1-2% every year.  As the person gets old, his or her energy expenditure also decreases. The declined in the expenditure of energy is due to increase mass of fats and decreased mass of muscles.

In order to prevent  declined metabolic rate and age-related weight gain, you must integrate a fitness program including muscle building and strength training to have a stable muscle mass that is metabolically active, as well as cardiovascular physical activity to avoid increased mass of fats and  maintain a high level of burning energy.