CAMP LEATHERNECK, Afghanistan – Dropping off some laundry, I couldn’t help notice the barking around the corner. More than a dozen Marines were laying on their bellies in the dirt, working their body cores in a series of exercises outlined in the CrossFit fitness program. They were with R4OG, a group sent here to prepare gear to be sent back to the U.S. as part of the drawdown of coalition forces. The acronym stands for Retrograde and Redeployment in support of Reset and Reconstitution Operational Group. Photographer Colin Kelly and I ended up back at Leatherneck this morning after hopping…