I think many people greatly underestimate the degree to which the body is an adaptive system and, specifically, the degree to which a sedentary lifestyle intera

I think many people greatly underestimate the degree to which the body is an adaptive system and, specifically, the degree to which a sedentary lifestyle interacts poorly with this aspect of our bodies. The thing that brought this into full relief for me was the story of Brian Jones, a member of the Starting Strength community. He fell off of a roof and shattered both legs. Doctor told him he would never walk again, etc., etc. But he did. And then he start lifting weights. Of course, his body adapted to the increasing load he was placing on it. Specifically, his body responded by growing muscle and making his bones more dense. His bones got so dense that the metal pins which were inserted into his leg bones after his accident started getting pushed out into the surrounding flesh and he had to have surgery to remove them (links to his story below). I would bet good money that the majority of bone breaks (excluding things like car crashes and obvious stupidity), even in children, are a result of our largely sedentary lifestyles interacting with our body's evolved tendency to not engage in metabolically expensive activity like growing muscle and denser bone unless it receives signals indicating that they are actually demanded by our environment. Brian Jones' story: Video form: https://startingstrength.com/resources/forum/articles-and-platform-videos/40189-barbell-training-rehab-brian-jones-story.html https://startingstrength.com/resources/forum/articles-and-pl... Written form: https://startingstrength.com/article/barbell_training_as_rehab https://startingstrength.com/article/barbell_training_as_reh...