Lieutenant Michael Patrick Murphy lost his life in June 2005 during a mission to kill or capture a Taliban leader hiding in the hills of Afghanistan's Kunar Province. Trapped in a firefight behind enemy lines, the Navy SEAL was gunned down after he abandoned cover in an effort to call for backup. His body was recovered on Independence Day and he was posthumously honored with 14 service medals, including the Medal of Honor, Silver Star, and Purple Heart. The last Arleigh Burke-class Navy Destroyer and a post office in Patchogue, New York, were named for him. The SEALS continued to teach cadets the workout he invented.

Lieutenant Murphy called his grueling workout "Body of Armor" – he did it while wearing a 25-pound flak jacket – but after his death, the folks at CrossFit renamed it the "Murph" and added it to their collection of "Hero Workouts, named for fallen soldiers. The regimen demands and develops cardio endurance and requires nothing more than the discipline to follow in the Lieutenant's bootsteps.

The "Murph" is a mile run followed by 100 pull-ups, 200 push-ups, 300 air squats, and another mile on the track. Practitioners are able to partition the calisthenics to fit their ability, but they are also encouraged to always hit the rep count. The point is to foster discipline as well as strength. Our recommendation: Front-load the air squats and always do pull-ups after push-ups to stretch out your forearms. The second run feels like a relief after all that pushing and pulling.

When you get tired – and you will get tired – remember Murphy, who exhaustively prepared for any fight he saw coming.