If the temperature is above 65 degrees Celsius and the humidity is less than 60, and if the track is dry and the wind is at zero, Usain Bolt can clock a high 9.4 and a high 18.9 as long as he remains healthy and fit for the entire season.
Bolt was off this target by less that a quarter-second and slightly more than a third-of-a-second in the 100m and 200m, respectively, in 2011. In 2010 and 2011, he engaged in scaled down workouts and lost time due to injuries. So, it is likely that he can achieve these ultimate targets in 2012 because he has resumed highly intense and full-scale workouts.
In 2008, Bolt was in his best shape. However, his technique was raw and unrefined at that time. He could have run a high 9.5 in the 100m if he did not intentionally slow down.
In 2009, Bolt participated in full-scale workouts, and his technique dramatically improved. However, due to engagements after his Olympic achievements, his background training suffered as he could not train regularly. In addition to that, he suffered injury in a car accident, which caused him to miss practice for 12 days. It is estimated that Bolt lost a month's training for the 200m. Despite all this, he still ran a 9.58 for the 100m and 19.19 for the 200m. He could have run a 19.15 in the 200m if there were no headwind and the humidity less than 60.
Bolt will train properly in 2012, and he has Yohan Blake to push him in practice. Blake’s 19.26 200m run will only persuade Bolt to not be the ‘slacker’ he is notoriously known to be in practice.
The weather in London is known for being wet and damp. In that case, Bolt may have to achieve these milestones elsewhere.