Usain Bolt push Bolt to do longer sprinting distances with the aim of making the 400 m event his primary event by 2007 or 2008. Bolt was less enthusiastic, and demanded that he feel comfortable in his sprinting. He suffered another hamstring injury in March 2006, forcing him to withdraw from the 2006 Commonwealth Games in Melbourne, and he did not return to track events until May. After his recovery, Bolt was given new training exercises to improve flexibility, and the plans to move him up to the 400 m event were put on hold. The 200 m remained Bolt's primary event
Usain Bolt to test him to prove that he was clean, stating, "We work hard and we perform well and we know we're clean". At the end of the 2008 athletics season, Bolt competed in the ÅF Golden League, beginning in Weltklasse Zürich. Despite having the slowest start among his competitors in the 100 m race, he still crossed the finishing line in 9.83 s. Even though the time was slower than both his newly set world record and Asafa Powell's track record, it was still among the top-fifteen 100 m finishes by any sprinter to that date. Bolt admitted that he