I run no more than 20 miles a week. i have been diagnosed with anemia (12.8 hgb). is this cuould be associated to "runners anemia"?

Need more informatio: Have you had work up with other laboratory testing? Ex. Reticulocyte ct, ldh, total bilirubin?

There are many...: Causes of anemia, and from this limited info it's hard to give specific advice or guidance. I would say that your anemia is mild (normal hct for a man your age is ~45%) and doesn't seem to be impactful on your physical activity. This may even be a normal HGB for you. More info, and trends over time would be helpful. Generally, anemia either reflects inadequate production or exacerbated rbc loss.