Abubaker Kaki Khamis is a member of an Arab tribe whose militias were the forerunner of the janjaweed.
But when they go on the road with the Sudanese athletics team, the two are roommates.
"We don't think: 'These are Fur, these are Arab,' " says Mr. Ismail at the ramshackle track and field stadium where they train amid dust and rubble. "It doesn't matter here."
The two are Sudan's brightest prospects for medals at the Beijing Olympics in August, despite having to train on a track riddled with cracks.
Yet their big day is in danger of being overshadowed by campaigners who are trying to use the Olympics to highlight China's poor record on human rights.
Darfur activists in the West have seized on the Beijing Olympics as a way to pressure China into ending its support for the Khartoum government, which is waging war against rebels in the war-torn western region. China consumes two thirds of Sudan's oil exports to fuel its voluminous economy and has sold military jets in return. Filmmaker Stephen Spielberg has already given up his role overseeing the opening ceremony of what campaigners are calling the Genocide Games.
Meanwhile, unrest in Tibet has intensified calls for China to improve its human rights record, as it promised to do to host the Summer Games. Beijing's Olympic flame – which was sent on a four-month, six-continent tour at the beginning of April – was protested raucously in several Western cities, and many world leaders are under pressure to boycott the Games' opening extravaganza.
Yet for a handful of young Darfuris, Beijing is a place for their dreams to come true. "Talk of a boycott makes me angry," says Ismail, who reached the 800-meter finals in Athens four years ago. "We have people in the team from Darfur who are running. If we lost the chance of the Olympics, we would have to wait another four years before having another chance."
Abubaker Kaki Khamis belongs to the Misseriya tribe, whose mounted Arab militias wrought havoc in southern Sudan where they fought for the government during a long and bitter civil war. They were the model for the janjaweed militia in Darfur that has raped and killed thousands of Ismail's tribemates.
Mr. Khamis is Sudan's best hope of a medal. Last month he was crowned world indoor 800-meter champion – the youngest ever – and since then has been feted by Sudan's President Omar el Bashir, had songs written for him, and been given parcels of land around Khartoum.
Like many young athletes he dreams of earning enough money to buy his parents a house. "Everything else is on hold now as I go for an Olympic win, but I need to help my family," he says, at the simple village of prefab huts where the athletes live.
Abubaker may be pinning his hopes on gold, but he has to cope with the same basic training conditions as everyone else.
Sudan's Olympic hopefuls use old paint cans filled with concrete for weight training. Their athletics stadium has never been finished. Piles of rubble surround the track. Because there are no floodlights, all training comes to a halt when the sun disappears in the evening.
Still, Jama Aden, who coached Abdi Bile to a world title in 1987, has spent the past six years trawling the country for talent. Though five members of his young team have picked up sponsorships with Nike, the rest survive on hand-me-downs., making a donation from the British Embassy in Khartoum the only way Mr. Aden can afford to get his team to Beijing.
"The facilities we have are poor compared to what there is in the West, but the athletes make up for it by being keen and willing to work extra hard," he says. "So what makes me upset when the Western world says we should have a boycott [is that] people don't realize that Darfur benefits from all this."
By the time he has finalized his 12-strong team for Beijing, he thinks half will be from Darfur, including members of the Zaghawa and Fur tribes, which support the region's rebel movements.
So while activists use the Olympics to pressure China on Sudan, the athletes see the Games as a chance to improve their country's reputation abroad. "People only think of bad things when they think of Sudan," says Nawal El Jack, a 400-meter runner, echoing her teammates' views. "Beijing is our chance to show people that we can do good things too."