I have been training since mid-December 2016 with Jon at Underground Fitness at the 59th Avenue (Glendale) facility,and it has been a great experience! I was referred to Jon by my Chiropractor, Dr. Stein, for strength/core training due to a longstanding shoulder injury from a car accident. Jon has helped me get back strength in my arms and shoulders, and he is very knowledgeable of various training techniques for this type of injury. I have learned a lot about overall fitness from Jon as well. Jon always has an upbeat and kind personality. I would highly recommend Jon and Underground Fitness! Cindi H.