Abstract
Advances in fitness tracker technology have led to increased measurements and predictions of physiological variables, such as VO2max and race prediction times. These data can help develop personalized exercise programs. The validity of wrist-based fitness trackers to estimate VO2max is mixed, and studies have not yet investigated race performance prediction. It was hypothesized that Garmin-estimated VO2max and race prediction times would fall within the INTERLIVE Network's consumer-level acceptability threshold (MAPE p p = 0.009. After 12-weeks of training, estimated VO2max from Garmin (45.00 ± 7.21 ml/kg/min) was significantly higher than criterion (42.43 ± 8.54 ml/kg/min), p=.007. Garmin's race predictions for the half-marathon (129.97 ± 18.29 min) were significantly faster than the official race times (137.55 ± 21.03 min), p=.003. Despite this, mean absolute percent error of VO2max and race prediction were below 10%, indicating the Garmin Forerunner 265 may be suitable for tracking general fitness trends.