Related Experiment Video
Updated: May 27, 2025

Assessing the Accuracy of Fitness Smartwatch Data for Cardiovascular and Physical Activity Monitoring: A Validation Study in Digital Health
Published on: February 21, 2025
Accuracy of smartwatches in predicting distance running performance
Jiansong Dai1, Gangrui Chen2, Zhonghe Gu1
1Department of Sports and Health, Nanjing Sport Institute, Nanjing, China.
Objective:
This study examined the accuracy of smartwatches in predicting running performance.
Methods:
A total of 154 amateur runners (123 males and 31 females) were recruited. After wearing the HUAWEI WATCH GT Runner for a minimum of six weeks, the runners' actual completion times for 5 km, 10 km, and half marathon distances were measured, resulting in 288 test instances. The predicted completion times for the same distances displayed on the watch on the test day were recorded simultaneously.
Results:
The actual and predicted performances for the 5, 10, and 21.1 km distances were highly correlated, with r ≥ 0.95 (p < 0.001) and r 2 ≥ 0.9 for all three distances, an error rate between the measured and predicted values of less than 3%, and intraclass correlation coefficient ≥0.9. The bias ± 95% limits of agreement were -20.4 ± 44.2 s for 5 km, 4.1 ± 299.1 s for 10 km, and 143.8 ± 400.4 s for the half marathon.
Conclusions:
This study confirmed that the smartwatch exhibits high precision in predicting 5 km, 10 km, and half marathon performances, with an accuracy exceeding 97%. The performance prediction features of smartwatches can effectively guide amateur runners in setting reasonable competition goals and preparing for races.
Related Concept Videos
Distance Corrections
Distance Measurements by Taping
Accuracy and Precision

