Bob is standing in a large field with his dog Heathcliff, and Catherine is standing in the same field 100 metres away from them. They start running directly towards each other, Bob and Catherine both run at 2 metres per second. Heathcliff runs twice as fast as Bob, and reaches Catherine while Bob is still some distance away, at which point Heathcliff turns and runs back to Bob. Heathcliff continues running back and forth in this way until they all meet. What is the total distance Heathcliff ran?