David Marshall holds the rank of Chief Instructor in Taiji received in 2012 (formally known as "Long Zhan") and was a longtime student of the late Grandmaster Jeffrey J. Guiffre (Florida) and the Yin Cheng family ( Yin Cheng Xing Jian Zong Hui) of Beijing (the late legendary Grand Master Wang Peisheng head of the Northern Wu Style Tai Chi Chuan school) David spent thirteen years training privately and weekly open classes with GM Guiffre to achieve authorization to teach and with Master Wang Naixiang in Beijing ( son of Wang Peisheng) in 2005 to achieve this rank.

David holds the rank of Qigong Master as certified by the incomparable Korean Monk Cheong Wol (In Sung Choi) in 2017 and world renowned Acupuncture and energy Master Jong Koo Kim of Seoul. David trained from 2011 to 2017 to achieve this certification.

David also trained full time in 2012 with Master Tang Li Long ( one of the original Wudang five dragons) of the Xuan Wu Pai at The Wudang Gong Fu Academy for seven months in Wudangshan Hubei Province ( The birthplace of Taoism and the Internal martial arts) 

And in 2019 trained full time for one month with Sifu Mark Rasmus in the Karen Village Chang Mai Thailand in high instructor level Elastic force qigong and Hermetics expanding his knowledge of mind and body practices.