Yoga, meditation and deep breathing have been shown to build flexibility, increase memory retention and improve focus. For people willing to explore the wide range of yoga classes available, a hot yoga studio, Bikram Yoga Chicago recently opened a new location, 47 W. Polk St. Classes take place in 105 degree rooms and students move through a series of 26 poses. The Chronicle’s Assistant Health & Fitness Editor, Katy Nielsen, takes you inside.