 The bikini design had become common in Western countries by the mid @-@ 1960s as beachwear , swimwear and underwear . By the late 20th century it had also become common as sportswear , particularly in sports such as beach volleyball and bodybuilding . By the early 2000s bikinis had become a US $ 811 million business annually , and boosted spin @-@ off services such as bikini waxing and sun tanning . 
