However, some skills are at their best in early adulthood. Athletic skills that require strength and speed are at their best in the early twenties. Skills requiring endurance are best in late twenties to early thirties.
Sexuality activity increases between the ages of 20-30, but declines from 30-40. The ability to reproduce declines. It declines after 35 in women and 40 years old in men.
Weight gain is normal in early adulthood. Many American adults gain about 20 pounds between the ages of 25 and 55. However, there is a risk when an adult gains more than ten pounds after age 18. Weight gain surpassing ten pounds increases the risk for diabetes and heart disease.
