I too am overweight, but have like yourself shot on and off for years. My veins are absolutely HORRIBLE!!! I strongly encourage you to STAY AWAY FROM THE LEGS!!! I have a friend who lost her leg from a miss, and I ALMOST lost mine from a miss! I registered, it never burned, everything went fine until I got it all in and there was no rush to follow..... Nothing! I have a big scar left from the very deep hole that my fist could fit down into. Also, my veins in my legs blow easily usually about halfway through or right there at the end of the hit and a knot comes up. Although..... There is a huge main vein (I think it's called femur??) That runs to your heart and down your leg..... I think most people when they find it usually go in the groin area. Anyone with more experience please correct me if I'm wrong. I have taken a flash light and in the dark put it close (touching at times) to the skin and ran it down my arms moving it around as need to see my veins, then had someone mark the vein with a pen. If you EVER try veins in your breast..... BE VERY CAREFUL ITS EXTREMELY EXTREMELY PAINFUL IF YOU MISS EVEN JUST A LITTLE! And whatever you do be choosy about who you let hit you..... Not everyone are the phlebotomist they think they are!!! Oh take a hot bath or get up and move some stuff around with a little weight to it..... Your veins will pop up when your heart starts pumping that blood faster. And stay hydrated..... Makes a huge difference!!!