Sports massage is a highly valuable treatment for a runner. Based on your mileage the frequency of massages should be determined. Runners who do not regularly use a foam roller post runs should opt for sports massage more frequently. Though sports massage helps recover very quickly and effectively, timing it right is very important. The reason is that you can feel extremely sore for the next few days and this can hamper your race. So a rough guideline to follow (this varies from runner to runner) is to do a sports massage at least 5 days prior to a big race/marathon. After completing the marathon, it is best to wait for at least 3 days to do deep-tissue/sports massage. The reason is that according to research, lactic acid built up in muscles needs that much time to buffer back to a neutral pH so as to not cause further tissue damage and soreness. A very light massage is fine after 2 hours but a sports massage will be most beneficial after 3 days post-marathon.