For the past few years, select members of the U.S. Marine Corps travel to the U.K. to participate in Royal Marines Commando training. True to the U.S. Marines’ institutional mentality to always adapt and improve, this provides them an opportunity to observe what works and how it can be implemented in the Corps’ physical regimen.

Some U.S. Marines (USMC) were also sent specifically to the Royal Marines’ Physical Training Instructor (PTI) program, a grueling 17-week process that produces combat-ready physical instructors that train the Royal Marines.

The assessment verdict: the British have a regimen far more sustainable and beneficial for the modern warfighter. USMC participants now recommend the Corps’ program focus on muscular endurance and functional fitness oriented toward combat.

In 2016, the USMC also launched the Force Fitness Instructor program, influenced by the PTI concept widespread in Commonwealth countries such as Canada, Australia, New Zealand, and the U.K.