Assessment of Peak Oxygen Uptake with a Smartwatch and its Usefulness for Training of Runners

Peak oxygen uptake (˙VO_2peak) is an important factor contributing to running performance. Wearable technology may allow the assessment of ˙VO_2peak more frequently and on a larger scale. We aim to i) validate the ˙VO_2peak assessed by a smartwatch (Garmin Forerunner 245), and ii) discuss how this parameter may assist to evaluate and guide training procedures. A total of 23 runners (12 female, 11 male; ˙VO_2peak: 48.6±6.8 ml∙min^-1∙kg^-1) visited the laboratory twice to determine their ˙VO_2peak during a treadmill ramp test. Between laboratory visits, participants wore a smartwatch and performed three outdoor runs to obtain ˙VO_2peak values provided by the smartwatch. The ˙VO_2peak obtained by the criterion measure ranged from 38 to 61 ml∙min^-1∙kg^-1. The mean absolute percentage error (MAPE) between the smartwatch and the criterion ˙VO_2peak was 5.7%. The criterion measure revealed a coefficient of variation of 4.0% over the VO2peak range from 38-61 ml∙min^-1∙kg^-1. MAPE between the smartwatch and criterion measure was 7.1, 4.1 and -6.2% when analyzing ˙VO_2peak ranging from 39-45 ml∙min^-1∙kg^-1, 45-55 ml∙min^-1∙kg^-1 or 55-61 ml∙min^-1∙kg^-1, respectively.