Mark C. Davis aka XBigMan describes his struggle with obesity:

Mark in July of 1991.

"As you can imagine from seeing my "Before" picture, I was not a healthy, happy camper. I was 34 years old and took pills for every ailment you could imagine. Neither the doctors nor the pills were very helpful. At every appointment, the nurse would make me hop up on the scale and it would max out at 350 lbs. One nurse would yell out: "Hey we need the obese blood pressure cuff over here!" A doctor told me: "I know why you have high blood pressure. It is because you are so FAT. Have you ever tried Slim Fast?" I had tried Slim Fast (along with every diet and supplement there was) and found it to be the most useless product I had ever tried."

Mark found a more compassionate doctor that suggested he might give exercise a try.

"I purchased an exercise bike and struggled to pedal for 2 minutes a day but kept at it until I could ride the bike for a half hour. I got bored working out alone and started exercising at a gym. I also began studying nutrition and applied my newfound knowledge to creating more balanced meals. What particularly helped me succeed in this effort was my discovery that my problem wasn't what I was eating, but what was eating me."

Having taken the step to deal with the emotional side of his overeating, Mark soon started seeing results.

Iron Man Florida (2006)

"I lost almost half of my bodyweight over 4 years and my energy increased ten-fold. I became much more productive in my work as a Certified Public Accountant, however, my employer decided to downsize what was left of me. I realized that I was being sent me a message: perhaps I wasn't placed on this Earth to count other people's money."

Mark took his next huge step. He enrolled at UC Berkeley to study exercise sciences and became an American College of Sports Medicine Certified Exercise Physiologist.

"I have trained for the last 18 years at the San Francisco Bay Club and have helped close to a thousand people achieve their goals. My clients have ranged from 10 to 86 years of age (and feeling younger!). Some have just a few extra pounds to manage; others face similar challenges to those I faced. I tend to gravitate towards working with the "tough cases": people who are afraid of exercise and feel intimidated."

Mark has appeared on NBC, ABC, Univision and has been quoted in the New York Times and the San Francisco Chronicle. He regularly trains for and competes in Ironman Triathlons including multiple Escape From Alcatraz events.

"Aside from being lucky enough to live in my native San Francisco with my beautiful wife and two daughters, my greatest joy is to help people who are struggling with their weight and share their joy when they find success."