Chargers coach Jim Harbaugh's workout video adds to viral offseason

EL SEGUNDO, Calif. -- New Los Angeles Chargers coach Jim Harbaugh has added to an offseason full of viral moments.

Since becoming the Chargers' head coach early this year , Harbaugh has joined the team's post-practice activities, such as strength and conditioning workouts with coach Ben Herbert. Harbaugh doesn't join these workouts in jest, either. He often moves at a faster pace than many players -- or at least tries his hardest to.

On Thursday, the 60-year-old Harbaugh joined in reverse sled pulls. Instead of using weighted plates, however, the offensive linemen stood on the sleds. In the viral video, Harbaugh grimaces as he backpedals and uses his hamstring muscles to pull a 300-pound lineman on a sled with the rest of the group.

The workout tradition dates back to Harbaugh's first head-coaching gig 20 years ago when he was at the University of San Diego, where players renamed a campus hill "Harbaugh Hill." Harbaugh used to sprint up the hill with his athletes to exhaustion. Once, he vomited midstride and didn't stop running.