Wearing weights all day long, will improve your strength (naturally). I've done this myself for about half a year now, but as "searcher" and other said, you'll get injured if you use too heavy weights. Basically if your daily job is to run around and be very active it'll be bad for you, but if you just go around doing nothing, you'll improve your strength and speed. It's like Bretty101 said: You can't move at full speed since that'll be bad for you