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).
Exercise is a key ingredient to increase metabolism. The aerobic workouts burn more calories in the short term, and weight training builds the muscles that will boost your metabolism in the long run. During heavy physical exertion, the muscles may burn through as much as 3,000kJ (717 kcal) per hour.