Tough Mudder: The Challenge Within

A group of Mudders are followed in this series, which begins with a look at the obstacles they have overcome in life and how their struggles have made them stronger.

The Grenado brothers, Bobby, Jimmy and Brant, are profiled as they work together to overcome the challenge of Bobby's diagnosis of multiple sclerosis at age 50. Included: The three siblings get ready to rock the Mudder course for a 10th time.

Mirna hits the course to prove she's capable of more than people who judge her for her size expect. Her story begins with chest pains and a talk with her cardiologist that motivate her to become a Mudder, an experience she blogs about at Fat Girl Running.

A veteran who was a member of Operation Iraqi Freedom muds as a way to cope with post-traumatic stress and a brain injury she suffered while overseas. Part of her story includes the camaraderie she finds on the course as she works to put her past behind her and focus on the future—and the mud—that lies ahead.

Mudders Mirna, Bobby and Denise get ready to crush the course and face their fears all over again.

In the Season 1 finale, a group of everyday heroes come to the end of their journey to accomplish completing a grueling Tough Mudder obstacle course.