It's a conspiracy on the part of the shoe companies!!!!! You're doing well with the strength work. Keep it up :)
Your feet continue to 'grow' as you AGE !!! :D
Ligaments and tendons stretch leading to an increase in size. Also the movement of the foot is why the fit of the shoe needs to be a size or two bigger than your foot measurement accommodate for socks, swelling etc etc.
So basically I need to buy new shoes :-)