These range from the number of calories burned in sexual activity to the value of physical education classes to the notion that burning 3, 500 extra calories leads mathematically to a one-pound weight loss.
Before I answer your question, let me clarify that while metabolism does drop with age (about 3 percent per decade) due to muscle loss and hormonal changes, it does not drop with exercise, but rather increases due to direct calorie burning during your workouts and indirectly through an increase in muscle mass as a result of your workouts.