A Romulan with blood on his face. Nanoprobes assimilating blood cells. Blood is the circulatory fluid that runs through most corporeal lifeforms in the universe. Its primary function is to carry nutrients and respiratory gases to cells and to remove waste products.
Muscle is more metabolically active than fat, and building muscle can help increase your metabolism (36, 37, 38, 39). This means you will burn more calories each day, even at rest (40). Lifting weights will also help you retain muscle and combat the drop in metabolism that can occur during weight loss (41, 42, 43, 44).
The lower your muscle mass, the slower your metabolism. With less muscle and a slower metabolism, it then becomes a lot easier to put body fat back on after coming off the diet. What can I do to speed up my metabolism? It's claimed that certain foods and drinks can boost your metabolism, including green tea, black coffee, spices and energy drinks. The evidence behind these claims is weak. While you don't have much control over the speed of your metabolism, you can control how many calories you burn through your level of physical activity.