People wish they had a "faster" metabolism, but most don't even know what it is. According to the Mayo Clinic Women's HealthSource, you can control some aspects of metabolism, but others are out of your hands.
There are two phases of metabolism: anabolic and catabolic. Anabolic is the constructive phase, where nutrient compounds are converted into substances the body can use. In the catabolic phase, substances are reconverted into simpler compounds, releasing the energy needed to keep the body going.
Metabolism is measured in calories. Your basal metabolic rate (BMR) is the number of calories you burn at rest to maintain vital body functions. That usually accounts for more than half the number of calories you burn in a day, but as you age, your BMR decreases at a rate of about 2 percent a decade.
But BMR declines as a result of lost muscle mass, so working hard to keep your muscles in shape will fend off this metabolic decline. That's why strength training to increase lean muscle mass is one of the best ways to boost metabolism and lose weight.