scanz
if you eat a slow carb meal, it's works better if you can slow up the absorption rate so it better matchs the carb absorption..
Different areas will have different fat consistancy, but another thing that can effect the absorption rate is how the insulin pools within the fat area, if it pools sitting near the muscle this can slow absorption day, as insulin absorps into fat a lot easier than mucsle, but then if you exercise the muscle it warms the fat layer up with quickens the absorption rate....
As to whether rubbing to warm the fat layer up first will work haven't got a glue, as it would be a different warmth than muscle movement and probably doesn't last as long!
And with rubbing the injection site you do risk rubbing an comtaminate into the site! Reason why you were told not to do it, but that was in the days when syringes were akin to harpoons though!!