Six miles, then 2.5 miles walking. I've been taking Norfloxacin, a fluoroquinolone anbiotic for food poisoning (two burritos from the local market). Side effects of this antibiotic include muscle soreness, stiffness, and increased tisk of soft tissue injury. As I ran today, my legs felt increasingly painful--calves, hamstrings and even my right hip flexor. I had to stop or risk serious injury. I've also stopped taking the antibiotic, and I'm using ice on my legs. Discouraging.