In the 1950s, the Royal Canadian Airforce produced a set of exercises for their airmen. Made up of five ‘Basic eXercises”, they were designed to be completed in sets based on age and job role. The exercises could be completed using bodyweight only, in a small space without the necessity to be able to run or walk any distance (you could substitute the suggested walk for a march or run on the spot). Although it was not explicitly stated, it’s difficult not to imagine that this was devised partly so that any P.O.Ws could still maintain fitness.
It didn’t take long for the 5BX to reach the general public, where they became incredibly popular. And Dr Orban, who had created the 5BX, devised a plan for women called the XBX – women had ten (or X, in Roman numerals) exercises to do.
Like the 5BX, the XBX was also popular. In fact, as recently as 2019, the XBX was still being cited by as famous a lady as Helen Mirren as being a core part of her fitness routine. The plans are (presumably) public domain by now, but there are still books being published using the plans, and copies exchange hands for ouch-y prices on Ebay.
Way back when State 11 Soft Tissue Therapy was but a baby, I wrote a post about the 5BX. Bizarrely, it is result #3 on Google for XBX.