For quite a while now, I've had a problem with my left leg/foot when running. After approx 4 miles it starts to tingle and gradually goes completely dead on me. This normally lasts for anywhere from 3 to 5 miles and then disappears again. For the rest of my run or race it doesn't give me any more trouble.
I've noticed also for several months that often I wake up in the morning with pins and needles in my arms. Is this cause for alarm, or could it be a trapped nerve somewhere?