The history-chasing exploits of Usain Bolt will take center-stage as the Olympic track and field competition begins Friday with the drug-tarnished sport seeking rebirth after a year of shame. Ten days of competition in Rio de Janeiro's Olympic Stadium get under way with officials keen to draw a line under a miserable 12 months which has left the athletics' image languishing at an all-time low. As ever, it will be left to track and field's greatest showman, Bolt, to restore the feel-good factor as the sport attempts to turn the page on the Russian doping scandal and corruption allegations. In his last Olympics, Jamaican star Bolt is gunning for 100m, 200m and 4x100m relay gold after sweeping the titles in 2008 and 2012. The first leg of Bolt's "Treble Treble" quest gets under way Saturday, with the opening heats of the 100m before the final Sunday. "As a young kid you grow up looking forward to the big games," said Bolt. "Championships are what matters. This is what I do." Just as he was at the World Championships in Beijing, Bolt is likely to find himself cast as the good guy in a hero vs. villain duel with long-time rival Justin Gatlin. Bolt has the 9.58sec 100m world record, but Gatlin is the fastest man in the world this season over 100m and he continues to polarize opinion over his two doping bans. At an Olympics which has seen ugly spats in the swimming pool involving athletes with drug-tainted records, it is a safe bet that Gatlin will once again find his past under scrutiny. Sebastian Coe, the president of the International Association of Athletics Federations (IAAF), says he hopes Gatlin will be treated politely by fellow competitors. "I can't change my view on (Gatlin) but he's eligible to compete and he should be accorded the same courtesy as any athlete who is within these rules is accorded," said Coe, who last year said the thought of Gatlin winning the 100m in Beijing made him "queasy." Coe said he hoped fans watching track and field would cast aside cynicism, even if the "the last year has sorely tested all of us." "I genuinely hope that those people that are watching our sport are watching with hope and they're watching with excitement and they're watching with belief," Coe said. The first of 47 gold medals — and 141 overall — will be decided Friday with the women's 10,000m, where Ethiopia's defending champion Tirunesh Dibaba will attempt to make Olympic history by becoming the first woman to win three consecutive times in an individual athletics event. Dibaba's tilt at history is just one of several compelling storylines unfolding over the second week of the Games. Saturday's action will see another star chasing three-peat immortality, when Jamaica's Shelly-Ann Fraser-Pryce attempts to complete an unprecedented hat-trick of Olympic gold in the woman's 100m. The 29-year-old however could face a stiff challenge from compatriot Elaine Thompson, the fastest woman in the world this year with a time of 10.70 seconds. Flying Dutchwoman Dafne Schippers could also be in the hunt for medals, but is widely seen as the bigger threat in the 200m. Among other highlights on opening weekend, Britain's Mo Farah will attempt to retain his 10,000m crown four years after his memorable romp to glory in London. Britain's Jessica Ennis will begin the defense of her heptathlon title Friday but will face a stiff challenge from Brianne Theisen-Eaton, the world leader this year. The Canadian's husband, US star Ashton Eaton, will be bidding to complete a family affair with victory in the decathlon, which starts on August 18.
