Had a sore back for 5+days now Monday i did cardio Tuesday i worked out weights upper.todsys i did my abs oh boy am i in intense pain.when i get up or sit back down it kills.when i also lay on the floor back facing upwards & my legs straight up u reach up 2 ur toes . Reverse crunches where u raise ur hips to touch the ceiling then extend out.ouch they both kill.Theres a big difference between burning & actual pain.Burning means u are working out properly but feeling pain STOP WORKING OUT! Wait until ur no longer in that pain or if u don't u could make it so much more painful & worse than u started with!!
Burning is just weakness leaving the body.
Go and see your doctor, or go and see a chiropractor, you might have a trapped nerve
Long warm shower an while you in the shower stretch it has always helped me