Smartwatches have become increasingly popular for fitness tracking, but their accuracy remains a topic of debate. A recent study from Germany investigated the reliability of these devices across swimming, cycling, and running. The researchers found that for heart rate monitoring during running, the difference between wrist-based data and a validated chest strap ranged from 3.1% to 8.3%.
Some women with specific body compositions experienced distorted heart rate readings, possibly due to external movements impacting signal strength. In swimming, smartwatches generally performed well in recording distances during front crawl. However, errors were more pronounced during medley swims, particularly if stroke transitions occurred mid-lap.
Stroke rate detection accuracy varied significantly between watch models. Smartwatches excelled in cycling and outdoor running under clear conditions.
Smartwatch accuracy in fitness tracking
For a 36.8-kilometer bike route, recorded distances varied minimally, from 0.03% to 4.2%. A 3.4-kilometer hilly running course showed distance variations ranging from 0.2% to 7.5%. Track running tests revealed polarized results.
Watches with a running track option had a deviation of only 0.8% over 4,000 meters, while other models displayed variations up to 1,020 meters. Testing watches on the inside versus outside curve of the track showed a 106-meter difference. To test your smartwatch’s accuracy, choose reliable references, test under clear conditions, repeat tests consistently, and ensure adequate satellite connections.
While smartwatches provide useful data, understanding which information is reliable and how to use it effectively is crucial for training and performance optimization. As the use of wearables becomes more common, researchers are also investigating discrepancies between smartwatch data and clinical testing measures. Differences in heart rate variability measurements could have significant implications for users relying on these devices for health monitoring and stress management.
