Weight bearing activities build better bones because bone cells respond by creating more bone tissue. The more the bone tissues are the stronger it builds up. This bone-building process is also called as osteogenesis. Only the bones involved on the exercise can generate new bone tissue so, it is really better to have a weight exercise that involves almost all of the bones.
In order to get ATP from sugar molecules in food, an organism needs oxygen present in order to oxidize the molecules.
