I am 51 and I have been doing system engineering work since early 80s. I agree it gets harder as time goes by. I used to love to work. Now I am running out at

I am 51 and I have been doing system engineering work since early 80s. I agree it gets harder as time goes by. I used to love to work. Now I am running out at 6pm. BTW back stretches are really under rated. 2min of it in the morning helps a lot all day.