The thought of living and training at 2,200m above-sea-level might not appeal to every endurance athlete, but those visiting Mexico City even for a short time should make the most of the scarce oxygen and amplify their stay. That said, this strategy isn't complete without considering levels of pollution in the Mexican capital. Nevertheless, well organised runners and cyclists can navigate outdoor areas in the city to a degree of success, while swimmers have their own isolated tubs set aside from main thoroughfares. These facilities are stitched together by a handful of small neighbourhoods where hotels . . .