I graduated some months ago now and built up slowly to doing 10k but over the last few weeks my legs feel achy even on rest days and when I run, a burning in my calves makes me stop. Stretching helps while on the run but I would think ha I g run three times a week,mi should be stronger than this. Not running fast either, just a comfortable pace. How can I sort this out? I do strength and flex exercises every day and that helps with knees but feeling fragile. Help!!