Sun Rongchun, 57, exercises with an improvised cervical traction device attached to a high bar at a sports complex in Shenyang, Liaoning province, China on April 9, 2019. (Photo by Sheng Li/Reuters)

Ukrainian emergency workers spray a plane with water hoses as part of a rescue training exercise at Boryspil International Airport outside Kiev, Ukraine, September 27, 2016. (Photo by Valentyn Ogirenko/Reuters)

A Ukrainian serviceman fires a 2S7 Pion self-propelled gun during military exercises near the village of Divychky in Kiev region, Ukraine, October 21, 2016. (Photo by Valentyn Ogirenko/Reuters)

A Thai Yoga enthusiast performs during a mass yoga exercise in Bangkok, Thailand, 16 June 2019. Hundreds of Thai and foreign Yoga enthusiasts took part in the mass Yoga exercise organized by the Indian embassy to mark the International Day of Yoga which annually celebrated on 21 June. (Photo by Rungroj Yongrit/EPA/EFE)

The Revere Hotel in Boston, Ma. celebrated its grand opening on April 18 with a vertical fashion show. The Boston Rock Gym provided the models who rappelled down the exterior of the 24-story hotel wearing outfits created by the students from the Massachusetts College of Arts and Design and by Ted Baker London.

Photo: A model walks down the side of Revere Hotel in Boston during a vertical fashion show for the Massachusetts College of Art and Design on April 18, 2012. (Photo by Dominick Reuter/EPA/Lauren Fish/Lauren Frohne/Globe photo)

Yoga instructor Sarah Henry leads a class during a paddleboard yoga session at Adventure Sports Miami on July 10, 2011 in Miami, Florida. The paddle board is said to give the body's core more of a workout then in a gym since the platform is unstable and one must use the muscles to remain balanced on the board. (Photo by Joe Raedle/Getty Images)

Romanian soldiers take part in a joint military exercise with NATO members, called “Agile Spirit 2015” at the Vaziani military base outside Tbilisi, Georgia, July 21, 2015. Georgian soldiers along with U.S. marines and platoon-size units from Bulgaria, Latvia, Lithuania and Romania are taking part in the exercises at the Vaziani military base outside Tbilisi. (Photo by David Mdzinarishvili/Reuters)

Margaret Morris dancers exercising on the sands at Saint-Idesbald. (Photo by Fox Photos/Getty Images). August 1929