I failed my first Marathon while training on Runna. But it wasn't Runna's fault. At the LA Marathon last year, I did not finish. I stopped after 18 miles. My

I failed my first Marathon while training on Runna. But it wasn't Runna's fault. At the LA Marathon last year, I did not finish. I stopped after 18 miles. My legs were in pain. My heels were in pain. I was afraid of rhabdomyolysis. But there was a hidden problem