Pffft! Nothing to it.
Eight weeks of playtime.
In the Marines, we had to run 26 miles a day with a 200 pound pack on our back. Our morning began at 4am with 150 pushups, 200 situps, 1000 Jumping Jacks, and THEN we had to hold our breath for 20 minutes while we made our racks tight enough to bounce an M-16 rifle 5 feet into the air.
After the 2 year length of the program, we all had .0001% body fat and could SPRINT full-out for 100 miles through the desert with a Volkswagon Beetle tied behind us . . . with the park brake ON.