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 and Herb Elliott (the Jamaican athletics team doctor). Elliott, a member of the IAAF anti-doping commission, urged those concerned about the issue to "come down and see our programme, come down and see our testing, we have nothing to hide". Mills had been equally ardent that Bolt was a clean athlete, declaring to the "Jamaica Gleaner": "We will test any time, any day, any part of the body...[he] doesn't even like to take vitamins". Bolt stated that he had been tested four times prior to the Olympics, and all had tested negative for banned substances. He also welcomed anti-doping authorities