He's the co-founder of the Barefoot Running Club in Boulder, Colo.
An in-line skating crash in 2006 left Sandler with multiple broken bones.
After 10 surgeries, Sandler could barely walk and doubted he would ever run again.
Now, Sandler runs more than 100 miles each week barefoot.
He says running shoes are the problem, not the answer.
He maintains running barefoot decreases the wear and tear on the rest of the body.
He tells a Steamboat Springs newspaper that barefoot running will be the next big fitness movement.