Department for Health Sciences, Medicine and Research, Faculty of Health and Medicine, Danube University Krems, 3500 Krems an der Donau, Austria.
Department of Engineering and Industrial Design, Magdeburg-Stendal University of Applied Sciences, 39114 Magdeburg, Germany.
Sensors (Basel). 2024 Jul 18;24(14):4675. doi: 10.3390/s24144675.
Smartwatches are one of the most relevant fitness trends of the past two decades, and they collect increasing amounts of health and movement data. The accuracy of these data may be questionable and requires further investigation. Therefore, the aim of the present study is to validate smartwatches for use in triathlon training. Ten different smartwatches were tested for accuracy in measuring heart rates, distances (via global navigation satellite systems, GNSSs), swim stroke rates and the number of swim laps in a 50 m Olympic-size pool. The optical heart rate measurement function of each smartwatch was compared to that of a chest strap. Thirty participants (15 females, 15 males) ran five 3 min intervals on a motorised treadmill to evaluate the accuracy of the heart rate measurements. Moreover, for each smartwatch, running and cycling distance tracking was tested over six runs of 4000 m on a 400 m tartan stadium track, six hilly outdoor runs over 3.4 km, and four repetitions of a 36.8 km road bike course, respectively. Three swimming protocols ranging from 200 m to 400 m were performed in triplicate in a 50 m Olympic-size pool, evaluating the tracked distance and the detected number of strokes. The mean absolute percentage errors (MAPEs) for the average heart rate measurements varied between 3.1% and 8.3%, with the coefficient of determination ranging from 0.22 to 0.79. MAPE results ranged from 0.8% to 12.1% for the 4000 m run on the 400 m track, from 0.2% to 7.5% for the 3.4 km outdoor run, and from 0.0% to 4.2% for the 36.8 km bike ride. For the swimming tests, in contrast, the deviations from the true distance varied greatly, starting at a 0.0% MAPE for the 400 m freestyle and reaching 91.7% for the 200 m medley with style changes every 25 m. In summary, for some of the smartwatches, the measurement results deviated substantially from the true values. Measurements taken while road cycling over longer distances with only a few curves were in relative terms more accurate than those taken during outdoor runs and even more accurate than those taken on the 400 m track. In the swimming exercises, the accuracy of the measured distances was severely deteriorated by the medley changes among the majority of the smartwatches. Altogether, the results of this study should help in assessing the accuracy and thus the suitability of smartwatches for general triathlon training.
智能手表是过去二十年中最相关的健身趋势之一，它们收集越来越多的健康和运动数据。这些数据的准确性可能存在问题，需要进一步调查。因此，本研究的目的是验证智能手表在铁人三项训练中的使用。测试了十种不同的智能手表，以测量心率、距离（通过全球导航卫星系统，GNSS）、游泳划水频率和在 50 米奥林匹克标准泳池中的游泳圈数的准确性。每个智能手表的光学心率测量功能与胸带进行了比较。30 名参与者（15 名女性，15 名男性）在电动跑步机上进行了五次 3 分钟的间隔跑步，以评估心率测量的准确性。此外，对于每种智能手表，在 400 米草地球场跑道上进行了六次 4000 米的跑步、六次 3.4 公里的丘陵户外跑步和四次 36.8 公里的公路自行车课程的距离跟踪测试。在 50 米奥林匹克标准泳池中进行了三次从 200 米到 400 米的游泳协议，分别评估了跟踪距离和检测到的划水次数。平均心率测量的平均绝对百分比误差（MAPE）在 3.1%到 8.3%之间，决定系数在 0.22 到 0.79 之间。400 米跑道上 4000 米跑步的 MAPE 结果范围为 0.8%至 12.1%，3.4 公里户外跑步的 MAPE 结果范围为 0.2%至 7.5%，36.8 公里自行车骑行的 MAPE 结果范围为 0.0%至 4.2%。相比之下，对于游泳测试，真实距离的偏差变化很大，从 400 米自由泳的 0.0%MAPE 开始，到 200 米混合泳的 91.7%MAPE，每 25 米变换一次泳姿。总之，对于一些智能手表，测量结果与真实值有很大的偏差。在较长距离且曲线较少的道路自行车骑行中测量的结果在相对意义上比户外跑步更准确，甚至比在 400 米跑道上测量的结果更准确。在游泳练习中，大多数智能手表之间的混合泳变化严重恶化了测量距离的准确性。总的来说，本研究的结果应该有助于评估智能手表在一般铁人三项训练中的准确性和适用性。
