What other changes in the body occur during puberty in boys and girls?
The "growth spurt"
A rapid increase in height, referred to as a growth spurt, usually accompanies puberty. This rapid increase in height typically lasts for two to three years. About 17%-18% of adult height is attained during puberty. Although the increase in height affects both the trunk and the limbs, growth in the limbs usually happens first. The growth spurt characteristically occurs earlier in girls than in boys, with girls having the growth spurt approximately two years prior to boys, on average. In girls, the growth spurt typically precedes the onset of menstruation by about six months.
Bone growth and mineralization
Puberty is accompanied by growth of bones and increases in bone density in both boys and girls. In girls, bone mineralization peaks around the time of the onset of menstrual periods, after the time of peak height velocity (growth spurt). Studies have shown that bone width increases first, followed by bone mineral content, and lastly by bone density. Because of the lag between bone growth and achievement of full bone density, adolescents may be at increased risk for fractures during this time.
Changes in weight and body composition occur in both boys and girls. Adolescent girls develop a greater proportion of body fat than boys, with redistribution of the fat toward the upper and lower portions of the body, leading to a curvier appearance. While boys also have an increase in the growth of body fat, their muscle growth is faster. By the end of puberty, boys have a muscle mass about one and a half times greater than that of comparably sized girls.
Maturation of the cardiovascular systems and lungs results in an increased working capacity of these organs, associated with an overall increase in endurance and strength. These changes are more pronounced in boys than in girls.