Hi and thanks for the query, It would certainly not be due to the exercise that you experienced swollen and sore lymph nodes. The most probably cause of this should be a local inflammatory process, and an infection should be ruled out. Measuring markers of inflammation like the erythrocyte sedimentation rate and C reactive protein levels coupled with a complete blood count, to search for raised white blood cells could guide us to know exactly if its an infection or not. A complete clinical review and follow up of the temperature charts could be helpful, even to localize a site of local infection. Post surgical thrombophlebitis, veins inflammation of the lower limbs should be considered and excluded. I think to be on the safe side, you should visit the treating physician for a clinical examination and laboratory testing to exclude an infectious process. Thanks and kind regards, Bain LE, MD.