The clashes erupted after supporters of the Islamic religious parties alliance (MMA) attacked the men and women contesting the race with batons and stones, police said.
The protesters blocked the race course and chased competitors away as they approached the sports stadium where they were expected to finish race.
A spokesman for the MMA told the Associated Press news agency that the alliance had warned organisers against holding the race "because it is against Islam".
"They want to undress the entire nation," Riaz Durrani said.
"It is indecent for women to run in the streets. They want the sisters and sisters-in-law of the nation to wear knickers and T-shirts."
Two months ago Islamic groups strongly criticised a race in Lahore, saying the female participants had violated Muslim dress code.
Those poor, pathetic, psychologically and physically castrated men of Islam. Humiliating, beating and degrading women seems to be the only way to assert their masculinity--that, and blowing themselves and their masculine organs to smithereens for 72 imaginary virgins.
On reflection, if I were a Muslim woman in those societies, I would probably really encourage them in the latter strategy.