Underwear is worn for many reasons. They keep outer clothes from being made dirty by sweat. Men's briefs provide support for the male sex organs, and women's brassieres (bras) do the same thing for their breasts. Some people wear corsets to make their torsos a certain shape. For more support and protection when playing sports, people often put on underwear that fits more tightly for extra support. Men may wear jockstraps and trunks (which are a type of boxer shorts). Women may wear sports bras and pelvic protectors. Sports bras lessens the chance of damage to the ligaments of the chest during vigorous exercises such as jogging.