an Olympic Marathon, "the words pain and suffering very rarely come up", says Rojas. "What comes up is 'I relaxed', 'I focused', 'I stayed calm'." But why seek that pain at all? "It's an amazing thing for people outside of running to get their heads

my mileage and practised running above 14,000 feet, but still I'd limped home after aggravating an old Achilles injury. Today I was ready for a charmed third try. I was fit, healthy and confident of a top-10 finish. Maybe I'd even break three hours

Ouch Your muscles burn – and basically everything's on fire. Science Many call this "going anaerobic," but there's little evidence that the pain arises from too little oxygen (or too much lactic acid). Rather, your brain recognises that you're too