Wearable Lactate Threshold Predicting Device is Valid and Reliable in RunnersBorges, Nattai R.1; Driller, Matthew W.2Journal of Strength and Conditioning Research: August 2016 - Volume 30 - Issue 8 - p 2212–2218 doi: 10.1519/JSC.0000000000001307 Original Research Abstract Author InformationAuthors Article MetricsMetrics Borges, NR and Driller, MW. Wearable lactate threshold predicting device is valid and reliable in runners. J Strength Cond Res 30(8): 2212–2218, 2016—A commercially available device claiming to be the world's first wearable lactate threshold predicting device (WLT), using near-infrared LED technology, has entered the market. The aim of this study was to determine the levels of agreement between the WLT-derived lactate threshold workload and traditional methods of lactate threshold (LT) calculation and the interdevice and intradevice reliability of the WLT. Fourteen (7 male, 7 female; mean ± SD; age: 18–45 years, height: 169 ± 9 cm, mass: 67 ± 13 kg, V[Combining Dot Above]O2max: 53 ± 9 ml·kg−1·min−1) subjects ranging from recreationally active to highly trained athletes completed an incremental exercise test to exhaustion on a treadmill. Blood lactate samples were taken at the end of each 3-minute stage during the test to determine lactate threshold using 5 traditional methods from blood lactate analysis which were then compared against the WLT predicted value. In a subset of the population (n = 12), repeat trials were performed to determine both inter-reliability and intrareliability of the WLT device. Intraclass correlation coefficient (ICC) found high to very high agreement between the WLT and traditional methods (ICC > 0.80), with TEMs and mean differences ranging between 3.9–10.2% and 1.3–9.4%. Both interdevice and intradevice reliability resulted in highly reproducible and comparable results (CV < 1.2%, TEM <0.2 km·h−1, ICC > 0.97). This study suggests that the WLT is a practical, reliable, and noninvasive tool for use in predicting LT in runners. 1School of Medical and Applied Sciences, Central Queensland University, Rockhampton, Australia; and 2University of Waikato, Hamilton, New Zealand Address correspondence to Nattai R. Borges, email@example.com. Copyright © 2016 by the National Strength & Conditioning Association.