Mark McClusky says for elite athletes today, pushing boundaries and breaking records is all about "the aggregation of marginal gains."
One of the reasons the Taliban has been so difficult to defeat in Afghanistan is its control over the local people. They have earned popularity by delivering a form of local justice.
But there are signs – even in some of the most troubled parts of the country – that the Afghan government and police are making inroads to change that.
The BBC’s David Loyn reports from Helmand Province in Afghanistan.