Original:  As a recap for the race, not only runners gave their best performances in this race, but several foreign teams - especially from Okinawa, Japan - played a great role adding a cultural exchange aspect to the event.
Revised:  As a recap for the race, not only runners gave their best performances in this race, but several foreign teams - especially from Okinawa, Japan played a great role adding a cultural exchange aspect to the event.
Edit intent: fluency