Couple running

Smartwatches could predict your marathon time with increased accuracy

Smartwatches are a popular training tool among runners

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Planning to do a marathon? A new way of analysing data from a smartwatch could help forecast how you will perform.

“Marathon prediction is very difficult,” says Thorsten Emig at the French National Centre for Scientific Research (CNRS), but he and his colleagues have developed a more accurate mathematical model to do the job.

Currently, most smartwatches estimate the wearer’s VO2 max – the maximum rate at which they consume oxygen during exercise – via heart rate measurements and use this estimate to predict their race times. …