I had a participant ask me why her leg tingles when she is in the warrior poses. She says it feels like it falls asleep, then when we come out of the pose she feels blood rush down. I, myself, feel that in a deep standing straddle forward bend. I promised her I would find out, so it would be really fantastic if someone could email be back with the answer!
Thanks so much! 
I suspect 2 possibilities. Though it would be helpful if you clarified which Warrior you are doing and how deeply it is being done. Warrior I could cause this if there is too deep a lumbar backbend. Warrior II could cause it if hips were uneven, of if the pelvis is as low as the knees. In both these cases the compression or misalignement of the low back could strain the femoral artery or nerve causing momentary loss of blood flow. In your case with standing spread leg stretch can also come from same scenario. Namaste mukunda
well, it’s not a 100% fix to your problem, but I’ve found it helps overall circulation and cramping to make sure you’re foot is in a possition where it’s not cramping. if it is, the rest of the leg will be tense and crampy.