Comparison of Electromyographical Signal Analyses for Estimating Lactate Threshold

Document Type

Conference Proceeding

Publication Date


Publication Title

Proceedings of the Southeastern American College of Sports Medicine Regional Conference


Background: Currently, no published literature exists comparing the most appropriate and efficient filtering methods of electromyographical (EMG) analyses to estimate the workload at which lactate threshold (LT) occurs.

Purpose: The purpose of this investigation was to evaluate and compare EMG transformations and time windows to predict LT.

Methods: Participants (n=14) completed a maximal exercise test on a cycle ergometer until exhaustion. Blood lactate was measured every minute, while EMG was recorded continuously at the vastus lateralis. EMG signaling was then transformed and filtered using two time-segment windows (i.e., 10 and 60 seconds), as well as three signal conversions (i.e., root mean square, smoothing, and peak amplitude averaging).

Results: Results indicated no mean differences between the EMG thresholds, for any of the filtering methods or time-segment windows, when compared to the LT criterion. Moderate correlations were seen when comparing the lactate and EMG time-curves ranging from 0.69 – 0.79.

Conclusions: EMG may be a useful tool to estimate the work rate associated with LT. Averaging EMG over a minute of time and continual 10-second recordings demonstrate comparable readings and allow an easier application of EMG threshold in the field.