OKLAHOMA CITY, Okla -- When you think of a strenuous, heart-pounding workout, yoga doesn't usually come to mind.
But during a recent class at Hidden Dragon in Oklahoma City, yoga instructor Ryan Tigner was faced with the unexpected.
"Having someone collapse and have a moment is not the norm," Tigner told KFOR.
50-year old Nick Zaizar had a preexisting heart condition and crumbled out of his Standing Warrior position.
"It was very abrupt, like a sack of potatoes hitting the ground," Zaizar...