John Krasinski, who played former Navy SEAL and GRS security contractor Jack Silva in the movie “13 Hours” joined Chris Pratt, another celebrity with a role under his belt as a Navy SEAL in “Zero Dark Thirty” to take part in “The Murph Challenge” on Monday: a fairly recent workout tradition intended to honor the memory of fallen Navy SEAL LT. Michael P. Murphy.

While many Americans choose to celebrate Memorial Day with barbecues and quality time with family and friends, thousands across the country set out to subject themselves to a grueling workout intended to honor the memory of Michael Murphy.  Murphy was the officer-in-charge of a four-man SEAL element participating in the ill-fated Operation Red Wings that would ultimately leave only one survivor, Marcus Luttrell.  Luttrell went on to write a book about the operation that was optioned into a major Hollywood movie, and Murphy was awarded the Congressional Medal of Honor for his heroic actions leading up to his death.

The workout known as the “Murph Challenge” coincides with a fundraising effort sponsored by military apparel company “Forged.”  To date, the fundraising efforts have brought in nearly $800,000 to the LT. Michael P. Murphy Memorial Scholarship Foundation.

The workout itself consists of a one mile run, followed by 100 pull ups, 200 pushups, and 300 body weight squats before setting out on another mile run to complete the circuit; all while wearing a 20-pound weighted vest or body armor.  Elite Crossfit athletes have been known to complete the Murph in as little as 25 minutes – while slow guys like this writer tend to forgo the timer and just try our best to survive the ordeal without betraying our cool demeanor or throwing up on our shoes.

Just trying to collect my thoughts at the Murph halfway point on Monday

“The ‘MURPH’ is more than just a workout, it is a tradition that helps push us, humble us, and dedicate a bit of pain and sweat to honor a man who gave everything he had,” the Murph Challenge website explains.

Pratt, who recently starred in the summer hit “Guardians of the Galaxy 2,” was vacationing in England along with Krasinski, who famously got into incredible shape when cast as one of the six men that disobeyed orders to engage Islamist Extremists attacking the Diplomatic compound in Benghazi on September 11th, 2012.  The two men each posted short videos to their social media accounts after completing the Murph challenge, in which they encouraged others to learn more about the sacrifice of LT. Michael P. Murphy and to take a moment out of their own Memorial Day celebrations to honor the men and women who have died in service to our country.

“It’s a day like today when we commemorate those fallen heroes and say thanks for all you do to make our dreams come true,” Pratt said.

The actors then said that they were going to order Murph Challenge shirts now that they’ve “earned it.”