Readers reply: How is it physically possible to continue breaking sporting records?

The long-running series in which readers answer other readers questions on subjects ranging from trivial flights of fancy to profound scientific and philosophical conceptsThis weeks question: Is it inevitable that consumerism will literally fill up the planet?Obviously, progressions in sports clothing technology must make a small difference to the abilities of an athlete - but how on earth is it physically possible that we continue to break world records, year on year? Are humans really faster o...