Mercer, seriously, search around this site before asking questions.
Somewhere a true believer is training to kill us. He is training with minimal food or water, in austere conditions, training day and night. The only thing clean on him is his weapon. He doesn't worry about what workout to do - his ruck weighs what it weighs; his runs end when the enemy stops chasing him. He is not concerned about 'how hard it is;' he knows either he wins or dies. He doesn't go home at night, he is home. He knows only the cause.