Sweatpants are a casual

Casual

In the European tradition, casual is the dress code that emphasizes comfort and personal expression over presentation and uniformity. It includes a very wide variety of costume, so it is perhaps better defined by what it isn't than what it is...

 variety of soft trousers

Trousers

Trousers are an item of clothing worn on the lower part of the body from the waist to the ankles, covering both legs separately...

 intended for comfort

Comfort

Comfort may refer to:*Comfort , by the rock group Failure*Comfort *Comfort Air, German airline*Comfort food*Comfort noise, artificial background noise used in radio and wireless communications to fill the silent time in a transmission*Comfort object, an object used to provide psychological...

 or athletic

Athletic

Athletic may refer to:* An athlete, or sportsperson* Athletic director, a position at many American universities and schools* Athletic type, a physical/psychological type in the classification of Ernst Kretschmer...

 purposes.
In Britain, Australia and New Zealand they are known as "jogging bottoms" or "track pants".

Design

Sweatpants are usually made from cotton

Cotton

Cotton is a soft, fluffy staple fiber that grows in a boll, or protective capsule, around the seeds of cotton plants of the genus Gossypium. The fiber is almost pure cellulose. The botanical purpose of cotton fiber is to aid in seed dispersal....

, and the chief characteristic distinguishing them from other athletic pants is the elastic band located around the ankle

Ankle

The ankle joint is formed where the foot and the leg meet. The ankle, or talocrural joint, is a synovial hinge joint that connects the distal ends of the tibia and fibula in the lower limb with the proximal end of the talus bone in the foot...

s. Sweatpants are traditionally ash gray in color

Color

Color or colour is the visual perceptual property corresponding in humans to the categories called red, green, blue and others. Color derives from the spectrum of light interacting in the eye with the spectral sensitivities of the light receptors...

 but are now available in essentially any color. They are usually quite "baggy" and loose, which makes them easy to slip into (and out of) and allows a great deal of flexibility and comfort. In addition, this design traps less heat than most conventional trousers, which may be a disadvantage in some contexts (such as cold temperature

Temperature

Temperature is a physical property of matter that quantitatively expresses the common notions of hot and cold. Objects of low temperature are cold, while various degrees of higher temperatures are referred to as warm or hot...

s) and an advantage in others (such as body heat

Thermoregulation

Thermoregulation is the ability of an organism to keep its body temperature within certain boundaries, even when the surrounding temperature is very different...

-increasing aerobic

Aerobic

Aerobic is a word that means "requiring air", where "air" usually means oxygen.Aerobic may also refer to:* Aerobic exercise, prolonged exercise of moderate intensity* Aerobics, a form of aerobic exercise...

 activities). The sweatpant variations listed below are made from different materials.
Sweatpants are widely used in schools, sports, etc. because they are comfortable and keep the cold out while they also don't get too hot in warmer temperatures.

Variations

There are many variations on the sweatpant design that have evolved to define their own categories of athletic pants. These variations include fashion pants, windpants, tearaway pants, and muscle pants.

Fashion pants

Fashion pants typically refers to "fashion

Fashion

Fashion, a general term for a currently popular style or practice, especially in clothing, foot wear, or accessories. Fashion references to anything that is the current trend in look and dress up of a person...

 conscious" sportswear

Sportswear

Sportswear or activewear is clothing, including footwear, worn for sport or physical exercise. Sport-specific clothing is worn for most sports and physical exercise, for practical, comfort or safety reasons....

, such as the pants produced by Juicy Couture

Juicy Couture

Juicy Couture is a contemporary line of both casual and dressy apparel based in Arleta, Los Angeles, California founded by Pamela Skaist-Levy and Gela Nash-Taylor in 1996...

. The distinguishing characteristic is that fashion pants lack the elastic band at the ankles.

Windpants

Very similar to, but not to be confused with sweatpants are windpants, also known as windbreakers, which are lighter and serve to shield the wearer from cold wind

Wind

Wind is the flow of gases on a large scale. On Earth, wind consists of the bulk movement of air. In outer space, solar wind is the movement of gases or charged particles from the sun through space, while planetary wind is the outgassing of light chemical elements from a planet's atmosphere into space...

 rather than insulate. Windpants are almost always made out of polyester

Polyester

Polyester is a category of polymers which contain the ester functional group in their main chain. Although there are many polyesters, the term "polyester" as a specific material most commonly refers to polyethylene terephthalate...

 or nylon

Nylon

Nylon is a generic designation for a family of synthetic polymers known generically as polyamides, first produced on February 28, 1935, by Wallace Carothers at DuPont's research facility at the DuPont Experimental Station...

. Some have polyester tricot. Some types of windpants have a separate inner liner made of cotton. Because of this Undergarments are not required while wearing windpants. Due to the substance's natural friction against both itself and human legs, nylon makes "swooshing" sound

Sound

Sound is a mechanical wave that is an oscillation of pressure transmitted through a solid, liquid, or gas, composed of frequencies within the range of hearing and of a level sufficiently strong to be heard, or the sensation stimulated in organs of hearing by such vibrations.-Propagation of...

s during walking

Walking

Walking is one of the main gaits of locomotion among legged animals, and is typically slower than running and other gaits. Walking is defined by an 'inverted pendulum' gait in which the body vaults over the stiff limb or limbs with each step...

. Windpants often have zipper

Zipper

A zipper is a commonly used device for temporarily joining two edges of fabric...

s on each ankle, allowing athletes to unzip the end of each leg to pull the pants over their footwear

Footwear

Footwear consists of garments worn on the feet, for fashion, protection against the environment, and adornment. Being barefoot is commonly associated with poverty, but some cultures chose not to wear footwear at least in some situations....

. Some windpants have zippers that run the full length so the pants can be simply unzipped entirely; in this case, shorts are normally worn underneath.

Tearaway pants

Tearaway pants, also known as breakaway pants, rip-off pants, or (in the UK) popper pants, are another variation of sweatpants, and are closely related to windpants. Tearaway pants are windpants with metal snaps running the length of both legs. Some tearaway pants have snaps on only part of the legs, but normally the snaps run the entire length. Some tearaway pants are reversible. Some do not have pockets but since shorts are usually worn underneath tearaway pants, many people open the top snaps to gain access to pockets in their shorts.

Sometimes, there are button

Button

In modern clothing and fashion design, a button is a small fastener, most commonly made of plastic, but also frequently of seashell, which secures two pieces of fabric together. In archaeology, a button can be a significant artifact. In the applied arts and in craft, a button can be an example of...

s above each set of snaps to add more closure. The buttons and snaps allow athletes to remove their tearaway pants in a timely manner to compete in some sports. Basketball

Basketball

Basketball is a team sport in which two teams of five players try to score points by throwing or "shooting" a ball through the top of a basketball hoop while following a set of rules...

 and track and field

Track and field

Track and field is a sport comprising various competitive athletic contests based around the activities of running, jumping and throwing. The name of the sport derives from the venue for the competitions: a stadium which features an oval running track surrounding a grassy area...

 are the two sports most commonly associated with tearaway pants and windpants.

Adidas

Adidas

Adidas AG is a German sports apparel manufacturer and parent company of the Adidas Group, which consists of the Reebok sportswear company, TaylorMade-Adidas golf company , and Rockport...

 is the largest manufacturer of tearaway pants, followed by Nike, Inc.

Nike, Inc.

Nike, Inc. is a major publicly traded sportswear and equipment supplier based in the United States. The company is headquartered near Beaverton, Oregon, which is part of the Portland metropolitan area...

Other manufacturers are Spalding

Spalding (sports equipment)

Spalding is a sporting goods company founded by Albert Spalding in Chicago, Illinois, in 1876 and now headquartered in Bowling Green, Kentucky. The company specializes in the production of balls for many sports, but is most-known for its basketballs...

, Russell Athletic, Teamwork Athletic Apparel, Wilson Sporting Goods

Wilson Sporting Goods

The Wilson Sporting Goods Company is a sports equipment manufacturer based in Chicago, Illinois, and currently is a foreign subsidiary of the Finnish company Amer Sports....

, And 1

And 1

AND1 is an athletic shoe company specializing in basketball shoes and apparel. Founded in 1993, the company's headquarters were located in Paoli, Pennsylvania before being relocated to Aliso Viejo, California.-Company history:...

, Reebok

Reebok

Reebok International Limited, a subsidiary of the German sportswear company Adidas since 2005, is a producer of Athletic shoes, apparel, and accessories. The name comes from the Afrikaans spelling of rhebok, a type of African antelope or gazelle...

, Champion, Polo Ralph Lauren

Polo Ralph Lauren

Ralph Lauren Corporation is a luxury clothing and goods company of the American fashion designer Ralph Lauren. Ralph Lauren specializes in high-end casual/semi-formal wear for men and women, as well as accessories, fragrances, home and housewares...

, Converse, Old Navy, Foot Locker, Tommy Hilfiger

Tommy Hilfiger

Thomas Jacob "Tommy" Hilfiger is an American fashion designer and founder of the premium lifestyle brand Tommy Hilfiger.-Early life:...

, Fila

Fila

Fila or FILA may refer to:*Fila , a South Korean sportswear manufacturer* Fila , an island of Vanuatu*Fila, Iran, a village in Lorestan Province...

, and numerous other brands.