STOP THE PRICKS: A VALIDATION STUDY OF A NONINVASIVE LACTATE THRESHOLD DEVICE

ABSTRACT Purpose: The aim of this study is to assess the validity of a noninvasive lactate threshold device (NID) to determine lactate threshold heart rate (LTHR) and aerobic threshold heart rate (AeTHR). Methods: Twenty-one recreational athletes completed a personalized graded exercise test on a treadmill. All participants wore the noninvasive device and blood lactate samples were taken at the end of 3-minute stages. Lactate threshold heart rate and aerobic threshold heart rate were then calculated using four traditional methods and compared against the same heart rate values calculated by the device. Results: No significant differences were found in lactate threshold heart rate and the aerobic threshold heart rate between the noninvasive device and four traditional lactate methods. Conclusions: This study provides preliminary support for the validity of the NID for estimation of LTHR (4mmol), but weaker support for validity at AeTHR (2mmol)

A Validation Study of a Noninvasive Lactate Threshold Device

International Journal of Exercise Science 12(2): 221-232, 2019. The lactate threshold is considered a key marker of endurance exercise performance and identification of this threshold is important in writing an exercise training program. Unfortunately, assessment of the lactate threshold has traditionally required venous or capillary blood samples and a specialized meter to assess blood lactate concentrations. Recently, a consumer grade, non-invasive device was developed to determine muscle oxygenation and estimate the lactate threshold. Purpose: The aim of this study was to assess the validity of a noninvasive lactate threshold device (NID) to determine lactate threshold heart rate (LTHR). Methods: Twenty-one recreational athletes (14 females, 39 ± 7 years, 29.1 ± 5.2% fat, 37.8 ± 6.0 ml·kg-1·min-1; 7 males, 42 ± 9 years, 16.8 ± 2.2% fat, 45.9 ± 6.4 ml·kg-1·min-1) completed a personalized graded exercise test on a treadmill. All participants wore the NID and blood lactate samples were taken at the end of 3-minute stages. LTHR was then calculated using two traditional methods (4 mmol/L and \u3e1 mmol/L increase) and compared against the same heart rate values calculated by the NID. Results: No significant differences (p = .87) were found in LTHR between the NID and the traditional lactate methods (NID: 167 ± 9 bpm, 4 mmol/L: 167 ± 12 bpm, \u3e1 mmol/L: 167 ± 12 bpm). Conclusions: This study provides preliminary support for the validity of the NID for estimation of LTHR