Todd Gabriel, a former Marine, has been doing the "Murph" workout for several years.
"It's a lot of volume, a lot of workload and it's painful," said Gabriel.
It's a workout performed by crossfitters in memory of Navy Lieutenant Michael Murphy who died in the line of duty in Afghanistan.
"Somebody paid the ultimate sacrifice for our country. The hero workouts are probably five, six times more difficult than a standard workout and so it's a chance to kind of give a piece of yourself," said Gabriel.
Wearing a 20 pound vest is prescribed during the entire workout.
Gabriel says it consists of a one mile run, 100 pull-ups, 200 push-ups, 300 squats and another one mile run.
"The important thing is that people are here doing it. That's really the important thing to really give a lot of effort into it, push yourself what you believe is imaginable for yourself," said Gabriel.
If you would like to more information, head to The Murph Challenge