Originally Posted by OBoile

Might be best to refrain from using that term unless you're discussing artwork then.


This is false. Aerobic exercise does not significantly increase the amount of lean muscle mass, nor does it signal the body to build/retain muscle to any significant degree.
Also, burning fat and increasing the amount of muscle are two distinct processes. One does not happen as a result of the other.
Also, muscle "density" isn't really a thing. Muscles can grow or shrink. Certain other adaptations within the muscles can occur, some of which are caused by aerobic activity, but that doesn't make them significantly more dense.
Finally, you are constantly burning fat reserves. Constantly. The consumption of fewer calories than what you expend is what causes fat loss. Aerobic exercise will increase caloric expenditure, but it isn't necessary for fat loss. So the "sufficient quantity" is 0.


Strength training. Lifting heavy things, or pushing against a sufficiently difficult resistance. This causes a different adaptation within the body than producing a low amount of force for an extended period of time, as is the case with aerobic exercise. Specifically it sends a strong signal to the body to build/retain as muscle. One look at the bodies of elite strength athletes vs elite endurance athletes should make this quite clear.