Final answer:
Factors such as anaerobic exercise, hormone levels particularly thyroxine, external temperature, and adjustments in energy intake verses expenditure influence an individual's basal metabolic rate (BMR). Exercise, exposure to cold, and certain health conditions like fever can increase BMR, while energy restriction can decrease it.
Step-by-step explanation:
Factors Increasing Basal Metabolic Rate (BMR)
Several factors can lead to an increase in an individual’s basal metabolic rate (BMR), which is the rate at which the body uses energy while at rest. One such factor is anaerobic exercise, including activities like sprints, high-intensity interval training (HIIT), and strength training. These types of exercises not only require substantial energy but also raise the BMR to help the body sustain the increased demand for energy even when at rest. Another significant regulator of BMR is the secretion of hormones by the glands. Notably, the hormone thyroxine, produced by the thyroid gland, increases the body’s metabolic activity; a higher level results in a higher BMR, while a deficit can significantly reduce the BMR.
External factors like temperature also affect BMR. For instance, exposure to cold causes the BMR to rise to generate the necessary heat to maintain the body’s internal temperature. Conversely, prolonged exposure to heat can lead to an increase in BMR as well. Additionally, increases in body temperature due to fever can lead to a substantial elevation in BMR, with each degree centigrade of fever potentially raising BMR by about 14-15%.
The body’s metabolism is subject to variations brought on by the balance of energy intake versus expenditure. When an individual experiences prolonged changes in food intake, such as during dieting, the body adjusts its BMR. While under-eating leads to a reduced BMR and preservation of fat stores, engaging in regular exercise can raise BMR, aiding in weight loss and improving energy utilization efficiency.