Carrying a bergen across different terrain at varying speeds is fun and challenging. Putting on a bergen puts you into a great posture meaning you are working muscles that need working and is a great challenge for all levels of fitness.
Remember noBODY gets left behind so come along and give it a try.
Tabbing is a military term, walking at a fast pace with a weighted bergen (Rucksack). In the British Army loaded marching is considered a core skill and is tested annually in an eight mile Combat Fitness Test carrying 15-25kg depending on the regiment. The term tab has its roots in an acronym, being an abbreviation of Tactical Advance to Battle.