<i>He ran 240 km (150 miles) in two days. He then ran the 40 km (25 miles) from the battlefield near the town of Marathon to Athens to announce the Greek victory over Persia in the Battle of Marathon (490 BC) with the word "Νενικήκαμεν" (Nenikékamen, 'We have won') and collapsed and died on the spot because of exhaustion.</i><p>So, after running 75 miles a day for the first two days, don't run another 25 miles the next day.<p>PS: <i>The story is improbable, as the Athenians would more likely have sent the messenger on horseback. </i>