Which of the following is not a component of health-related fitness?
a. cardiorespiratory fitness
b. bone density
c. muscular strength
d. flexibility

exercises that improve cardiovascular fitness improve body composition, because they
a. increase body fat
b. increase body tissue
c. release energy
d. store energy

Bone density is not a health-related fitness component. There are only five health-related fitness components and these are: 
a. Cardiovascular Endurance - refers to the ability of your circulatory and respiratory systems, how they work together.
b. Muscular Strength - the maximum amount force that your muscles can exert in one effort.
c. Muscular Endurance - the ability of your muscles to perform without feeling easily fatigued.
d. Flexibility - the ability of your joints to move and bend through a full range of motion.
e. Body composition - refers to the proportions of your lean and fat tissue.

Exercises that improve cardiovascular fitness tend to improve body composition because they release energy. When the body exercises, stored energy is expelled through respiration and processes in the cells. With this, fat is used up as a source of energy and is then burnt and released giving way to improved body composition.