Question: Chinese poles have been used for the dancing that has recently gained popularity as a mainstream form of what activity?
Context: Pole dance combines dance and acrobatics centered on a vertical pole.  This performance art form takes place not only in gentleman's clubs as erotic dance, but has also recently gained popularity as a mainstream form of fitness, practiced by many enthusiasts in gyms and in dedicated dance studios.  Amateur and professional pole dancing competitions are held in countries around over the world. You Got Served is a 2004 American dance drama film written and directed by Chris Stokes, manager of its stars, recording artist Marques Houston and boy band B2K.  The plot concerns a group of dancers, who take part in a street dancing competition.  It was released by Columbia Pictures' Screen Gems division on January 30, 2004, and was produced by Marcus Morton, Cassius Vernon Weathersby, Billy Pollina, Kris Cruz Toledo.  It opened at #1 at the box office during Super Bowl weekend with $16 million grossed in its first week.  It has recently gained a cult following.  It was filmed on May 1, 2003 through June 25, 2003 and released on January 30, 2004.  Houston and Grandberry later starred in the 2004 film "Fat Albert". Garth Hill College (also Garth Hill and Garth) is a secondary school in Bracknell, England and is on the same site as the Wick Hill Centre, which is now part of Bracknell and Wokingham College .  It was created as Garth Hill School (a Comprehensive) in September 1969 from an amalgamation of Wick Hill Secondary Modern School (opened 1956) and neighbouring Garth Grammar School (opened 1965), the name of the latter referring to a former local fox hunt.  The school underwent a £40 million rebuild in 2010, opened by HRH Princess Anne the same year.  The School has recently gained yet another new building for the sixth form of Garth Hill, costing £6 million and opened in 2015 by the Mayor of Bracknell. Bushcraft is a popular term for wilderness survival skills.  The term was popularized in the Southern Hemisphere by Les Hiddins (the Bush Tucker Man) as well as in the Northern Hemisphere by Mors Kochanski and recently gained considerable currency in the United Kingdom due to the popularity of Ray Mears and his bushcraft and survival television programs.  It is also becoming popular in urban areas where the average person is separated from nature, as a way to get back in tune with their rural roots.  The phrase bushcraft's origin is from skills used in the bush country of Australia.  Often the phrase 'wilderness skills' is used as it describes skills used all over the world. Natural childbirth is childbirth without routine medical interventions, particularly anesthesia.  Natural childbirth arose in opposition to the techno-medical model of childbirth that has recently gained popularity in industrialized societies.  Natural childbirth attempts to minimize medical intervention, particularly the use of anesthetic medications and surgical interventions such as episiotomies, forceps and ventouse deliveries and caesarean sections. Natural childbirth may occur during a physician or midwife attended hospital birth, a midwife attended homebirth, or an unassisted birth.  The term "natural childbirth" was coined by obstetrician Grantly Dick-Read upon publication of his book "Natural Childbirth" in the 1930s, which was followed by the 1942 "Childbirth Without Fear". Michael Kelly Guitars is an American guitar, bass and mandolin company, who imports high quality instruments manufactured to their specifications (mainly from S. Korea).  Based in Clearwater, Florida, they are a division of Guruz Media Inc, also based in Clearwater, Florida.  Michael Kelly Guitars was founded in 1999.  The company has recently gained popularity, particularly due to the release of their new Mod Shop Guitars, where they take some of their standard designs and swap out the pickups using Lindy Fralin, Seymour Duncan, TV Jones, Bare Knuckle and Fishman.  They are also hot rodding the wiring, and adding coil tap volume and tone pots to some of the Mod Shop Designs.  They have also gained popularity due to their Dragonfly II acoustic bass, which has been used by Duff McKagan of Guns N' Roses, Shavo Odadjian of System of a Down, Tony Bigley of Souls Harbor, and others #see  for a full list#. In historical linguistics, the wave model or wave theory (German "Wellentheorie") is a model of language change in which a new language feature (innovation) or a new combination of language features spreads from a central region of origin in continuously weakening concentric circles, similar to the waves created when a stone is thrown into a body of water.  The theory was intended as a substitute for the tree model, which did not seem to be able to explain the existence of some characters, especially in the Germanic languages, by descent from a proto-language.  At its most ambitious, it is a wholesale replacement for the tree model of languages.  During the 20th century, the wave model has had little acceptance as a model for language change overall, except for certain cases, such as the study of dialect continua and areal phenomena; it has recently gained more popularity among historical linguists, due to the shortcomings of the Tree model. Poetry has been featured extensively in Thai literature, and constituted the near-exclusive majority of literary works up to the early Rattanakosin period (early 19th century).  It consists of five main forms, known as "khlong", "chan", "kap", "klon" and "rai"; some of these developed indigenously while others were borrowed from other languages.  Thai poetry dates to the Sukhothai period (13th–14th centuries) and flourished under Ayutthaya (14th–18th centuries), during which it developed into its current forms.  Though many works were lost to the Burmese conquest of Ayutthaya in 1767, sponsorship by subsequent kings helped revive the art, with new works created by many great poets, including Sunthorn Phu (1786–1855).  Prose writing as a literary form was introduced as a Western import during the reign of King Mongkut (1851–68) and gradually gained popularity, though poetry saw a revival during the reign of King Vajiravudh (1910–25), who authored and sponsored both traditional poetry and the newer literary forms.  Poetry's popularity as a mainstream form of literature gradually declined afterwards, although it is still written and read, and is regularly employed ceremonially. Chinese poles are vertical poles on which circus performers climb, slide down and hold poses.  The poles are generally between 3 and in height and approximately 2 to in diameter.  Some poles have a slightly larger pole that rotates around the static central pole using ball bearings.  This rotating pole allows a performer to spin on the vertical axis, giving a performer the ability to incorporate rate of spin into what would otherwise be static moves.  Bringing the body closer into the pole causes the performer to spin faster.  A few Chinese pole tricks have been incorporated with pole dancing techniques. Rabbinic Judaism or Rabbinism has been the mainstream form of Judaism since the 6th century, after the codification of the Talmud.  Rabbinic Judaism gained predominance within the Jewish diaspora between the 2nd to 6th centuries, with the development of the oral law and the Talmud to control the interpretation of Jewish scripture (specifically the Masoretic Text) and to encourage the practice of Judaism in the absence of Temple sacrifice and other practices no longer possible, while waiting for the Third Temple.
Answer: fitness