Yoga pants are a type of flexible, form-fitting pants designed for the practice of yoga as well as other activities that involve a lot of movement, bending and stretching. Some of the other activities include: martial arts, dancing, Pilates, aerobics, etc. These pants are generally made of cotton, spandex, nylon, polyester or a light and stretchy synthetic material. They are usually tight-fitted, colored black, and have an elastic waistband folded over at the top. Although designed specifically for yoga, the pants are also casually worn by women in daily life. 
Although Yoga has been around for over 5000 years,[better source needed] the polyamide fiber, otherwise known as nylon which is used to make up yoga pants, was invented by chemists Wallace Carothers, William Hanford, Donald Homes, Joseph C. Shivers and James Wray in the 1920s and 30s. The polyurethane, that in the 50s became known as Spandex, was created by Matt Donkersloot and Taylor Lindsay.Spandex was first marketed in the U.S. in 1959, and is what was used to give yoga pants their form-fitting design. Although clothing articles similar to yoga pants have been worn since the 50s, yoga pants did not truly become popular until the early 2000s.
Other types of yoga pants can be made out of cotton which was discovered in a cave near Tehuacán, Mexico, and dates back to around 5800 BC. Synthetic fibers such as nylon, which are also used to make yoga pants, are one of the biggest competitors to cotton which is the best selling fiber in the U.S., and one of the top selling fibers in the world.
Types of Yoga Pants 
There are various types and styles of yoga pants. These include the boot cut and flared yoga pants. The boot cut and flared remains the most popular type of yoga pants that is generally used for casual wear, as maternity wear, and for physical activities. The flat and fold-over waists are utilized to provide comfort and versatility. Another style of yoga pants that are full-length and fitted are utilized as tights or leggings when worn. The third style is crop, fitted yoga pants where the pants lie above the ankle that is similar to capri pants where it is often times utilized for a more flattering, versatile, and dressier look.
Some of the most popular brands of yoga pants include: Victoria's Secret, TNA Aritzia, GAIAM, Hard Tail, Lucy Activewear, Vertical Athletics, Lululemon Athletica, Tuff Athletics, and Prana. All of these brands feature many different styles of yoga pants. Some of the different styles include: capris pants, cropped pants, low-rise pants and more. Most yoga pants come in black, however, the "classic" yoga pant colors include: navy, white, pink, blue, brown and charcoal.
Lululemon Athletica Inc. sued Calvin Klein Inc. claiming that Calvin Klein's "Performance" brands infringed three patents for Lululemon pants. Lululemon filed the complaint on 13 August 2011 in federal court in Wilmington, Delaware. Lululemon seeks unspecified damages, including lost profits and royalties, and a court order barring the conduct.[not in citation given]
Lululemon was founded in Vancouver in 1998 and recognizes itself as a pioneer and innovator of yoga and exercise pants. Lululemon, which has 48 stores in Canada and 108 stores in the U.S., sells products patented under the brand name Astro Pant. Calvin Klein's alleged infringing products include its performance knee-length running tights and performance compression overlapping waistband pants. Calvin Klein was acquired in 2003 by PVH Corp., which also owns the Tommy Hilfiger label.
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- What to Wear with Yoga Pants
- C&O Apparel Tuff Athletics Yoga Pant
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- Workout Clothes: The Best Pilates and Yoga Pants for You
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- Media related to Yoga pants at Wikimedia Commons