Avsnitt 6

The thoroughbred racehorse is one of the greatest athletes on the planet, galloping with incredible speed and stamina for such a large animal. It is the result of unnatural selection, and exists on a knife edge between glory and catastrophic failure. The team explore how this animal has been biologically engineered for speed . They dissect an elite racehorse to reveal the extraordinary spring system that propels it to 45mph, its super-sized organs and built-in turbo-booster. Simon Watt visits the top breeding centre in Europe to find out how to produce a champion; and Mark Evans investigates the science behind their phenomenal performance and their vulnerability to injury