Basal Metabolism Activities

Basal Metabolic Rate (BMR) is the number of calories expended by the body to maintain its day-to-day functions. The body uses energy, or calories, constantly as it breaks down and distributes food to keep itself operating. Basal metabolism activities are the activities the body participates in every day, whether or not you leave your bed. Each person has a different BMR, impacted by body composition, genetics and activity level.

Breathing

• Breathing is a caloric expenditure covered under basal metabolism.

  When you inhale, the external intercostal muscles (found between the ribs) contract, causing your ribcage to lift up and out. The diaphragm also contracts during inhalation. When you exhale, cells work through elasticity to return your lungs to normal volume. Each of these activities contributes to your basal metabolism by expending calories. While resting, you breathe 15 to 18 times per minute, according to retired Harvard instructor John W. Kimball's website.

Body Temperature Regulation

• Sweating is the body's response to changes in core temperature.

  The body works to maintain its ideal core temperature, which ranges in humans from 97.7 to 99.5 degrees Fahrenheit. The hypothalamus, sometimes called the body's thermostat, is located in the brain and directs the body to make physiological changes in response to temperature. For example, on hot days, temperature receptors in the skin inform the hypothalamus of the heat. In turn, the hypothalamus directs the body to sweat. These constant activities require the expenditure of calories.

Growth

• Children are growing constantly, and so are adults.

  A big reason children burn so many calories is because they are growing so quickly. Growth contributes to basal metabolism because of the caloric expenditure involved. Cells multiply to form tissue, which make up organs, including the skeletal system. When organs grow, calories are needed to support cell growth. Muscle growth is another type of growth that becomes part of basal metabolism. The body repairs muscles after you work out, and then the body builds new, larger muscles.

Blood Circulation

• The circulatory system distributes oxygen-rich blood throughout the body. The circulatory system includes three main parts: pulmonary, coronary and systemic circulation. Blood traveling back and forth from the heart to the lungs is pulmonary circulation. The blood traveling through the veins of the heart is called coronary circulation. The rest of the tissues of the body receive blood through systemic circulation. Energy is expended when the heart pumps blood by contraction through the aorta and to the rest of the body.