People reach physical maturity at about 19, as they reach early adulthood. During middle adulthood, they begin the ageing process.
Life Stage: Physical characteristics:
Early adulthood: Reach full height and strength.
Have developed sexual characteristics and are able to reproduce.
Woman are at their most fertile.
Middle adulthood: Begin to show signs of ageing, such as greying hair.
Begin to lose muscle tone and strength.