How long has training in the outdoors been in use?

Outdoor Development, by whatever name it has been known, has been used for many years to meet the training needs of organizations. In 1907 Baden-Powell founded the Scout Movement with the aim of getting young people out of the towns and into the fresh air in order to “Stiffen the slouching slum-dweller and sharpen the lazy schoolboy”. In 1940 Kurt Hahn founded Outward Bound after noting that older sailors more likely to survive sinking during WWII. He produced a programme that gave young sailors new experiences which helped them to realise and understand their own potential and limitations and improve survivability. At about the same time the War Office Selection Board used simple exercises in the outdoors to test, develop and appoint leaders in the Army which focused on leadership, team work and problem solving. From about the 1960’s onwards it gathered momentum and began to take shape and training using the outdoors is now commonplace throughout many organisations.

From http://www.my-peakpotential.com/