During Middle Adulthood, Aerobic Capacity Declines As:​

During middle adulthood, aerobic capacity declines as:​

A) less oxygen is taken into the lungs and less blood is pumped by the heart.
B) sensitivity to insulin is lost by the muscle tissues.
C) lean-body mass, which includes muscle, is replaced by fat.
D) large amounts of calcium are lost by the bones, making them porous and brittle.