When I was a pre-teen, my Mom bought a 5BX booklet and 3 10BX booklets, one for each member of the family.  I was never good at being a regular exerciser, but my Mom has done her 10BX routine her whole life.  She eventually lost her book, but she still does her routine three times a week.  She is not tapering off though, still stuck at the highest level she got to.  She is not growing old willingly : -)

What a memory!  thanks for the show.