The Olympic Journey: How Far, How Fast? (BBC2, 5.30pm)Records are there to be broken. And in this documentary, ahead of the World Athletics Championships in Qatar this October, Gabby Logan investigates the possible limitations of human athletes, and considers the type of records that may be set in the future. Why are runners are obsessed with pushing themselves further and further? And will we ever see the men's 100m run in less than nine seconds, or a marathon in under two hours? Years ago it...
