Diaulos (Greek: Δίαυλος, English translation: "double pipe") was a double-stadion race (c. 400 m.) introduced in the 14th Olympiad of the ancient Olympic Games (724 BC). Scholars debate whether or not the runners had individual "turning" posts for the return leg of the race, or whether all the runners approached a common post, turned, and then raced back to the starting line
Dolichos or Dolichus (Greek: Δόλιχος, English translation: "long race") in the ancient Olympic Games was a long-race (ca. 4800 m) introduced in 720 BC. Separate accounts of the race present conflicting evidence as to the actual length of the dolichos. However, the average stated length of the race was approximately 18-24 laps, or about three miles. The event
was run similarly to modern marathons - the runners would begin and end their event in the stadium proper, but the race course would wind its way through the Olympic grounds. The course would often flank important shrines and statues in the sanctuary, passing by the Nike statue by the temple of Zeus before returning to the stadium
Diaulos
Was a double stadion race. The race was 200 yards in one direction and then the athletes had to run around one post and run back another 200 yards.
Dolichos
Translates to "long race". The dolichos was the longest running race in the ancient Olympics, measuring about 3 miles in length.