I saw Colin Jackson on the TV saying you get more endurance as you get older – and he was an athlete, so he should know these things. Is it true and if so, why?
Sam Norton, by email

Matt Hart answers: For athletes, an increase in endurance with age is the natural result of years of aerobic conditioning. Endurance is a feature of fitness that takes time to build, so a younger athlete would have to be extremely naturally gifted to match the performance of older competitors.
As you age you experience a steady decline in sporting performance, but this is heavily biased towards loss of speed and power rather than endurance. This is because we lose our fast-twitch muscle fibres (the ones sprinters use to make them run at speed) but hang on to our slow-twitch ones (which endurance athletes use to keep going for hours). Because of this, it is possible to enhance your endurance fitness even while your top-end power is in decline.