How does exercise influence resting metabolic rate (RMR)?

Regular exercise can elevate resting metabolic rate (RMR) over time due to several physiological adaptations that occur as a result of consistent physical activity. When a person engages in regular exercise, particularly resistance training or high-intensity interval training, there is an increase in muscle mass. Muscle tissue is metabolically active and requires more energy to maintain than fat tissue. As muscle mass increases, the energy expenditure at rest also rises, leading to an elevated RMR.

Additionally, exercise improves overall metabolic efficiency and can enhance the body's ability to utilize energy substrates, which contributes to an increase in the resting metabolic rate. The hormonal changes associated with regular exercise, such as increased levels of certain hormones like growth hormone and testosterone, can further support an increase in muscle mass and metabolic rate.

Furthermore, the process of recovery from exercise also plays a role; after a workout, the body expends energy to repair muscles and replenish energy stores, a phenomenon known as excess post-exercise oxygen consumption (EPOC). This elevated energy expenditure can contribute to a higher RMR in the long term.

In summary, the effect of regular exercise on RMR is significant, as it leads to increases in muscle mass and metabolic activity, ultimately resulting in a higher resting metabolic rate.