The Chinese Market Crash in context. How big is the market, how many investors does it have and does it tell us anything about the wider Chinese economy? Sprinters legs It may seem strange, but world class runners don\u2019t move their legs faster than average park runner. That\u2019s the claim anyway \u2013 is it true and if so what is it that makes athletes like Usain Bolt and Justin Gatlin run so fast?