metabolism

Basal metabolic rate (BMR) is the rate of energy expenditure per unit time at rest. It can be expressed in units ranging from watts, milliliters of oxygen consumption per minute, or joule per hour per kilogram of body mass. The amount of oxygen an individual takes in and utilizes at rest is equal to 3.5 milliliters of oxygen per kilogram of body weight per minute or one Metabolic equivalent to oxygen consumption referred to as one MET. METs estimate the intensity of aerobic activities based on oxygen consumption during and compared to a resting state.

Catabolism or catabolic means the breakdown of complex molecules to simpler ones with release of energy or destructive metabolism. Catabolism is the process of transforming chemical fuels such as glucose into energy in the form of adenosine triphosphate or ATP. Catabolic hormones include epinephrine, cortisol, and glucagon.

Anabolism and anabolic means the synthesis of complex molecules from simpler ones with the storage of energy or constructive metabolism. The processes produce growth and differentiation of cells, increase in body size, and involve synthesis of complex molecules. Anabolic hormones in the human body include testosterone, insulin, growth hormone, and Insulin-Like Growth Factors or IGF. These hormones promote tissue growth. Resistance training promotes tissue growth in part by increasing these hormones.

Ketone bodies are three water soluble molecules that are produced by the liver during times of fasting, carbohydrate restrictive diets, starvation, prolonged intense exercise, or inadequately treated type 1 diabetes. Ketone bodies are manufactured by the liver when too much protein is being used for energy. The dangers of ketone formation are that ketones are toxic to the brain and central nervous system function. Ketone presence in large enough quantities for prolonged periods of time in extreme cases may cause death. Ketone and keto-acidosis are terms that describe this condition.

Eating certain foods, water with lemon, lifting weights for the most part, or running sprints do not burn fat. Any of these may burn calories or create a caloric deficit, but do not necessarily burn fat. Burning fat is dependent on reaching and maintaining a target heart rate for an extended time. There are three energy systems that allow for muscle contraction. These energy systems are ATP-PC, anaerobic glycolysis, and aerobic metabolism.