Physiological machine learning

Blood Lactate Estimation

Predicting blood lactate from non-invasive physiological signals using linear, ensemble, and Bayesian hierarchical models.

A cyclist wearing a metabolic gas-exchange mask rides a stationary bike while a technician monitors the test.

Can blood lactate be estimated from wearable physiological signals without drawing blood?

Blood lactate testing is a gold-standard method for assessing fatigue and physiological response during endurance exercise, but collecting lactate requires repeated blood draws that are time-consuming and disruptive to training. Meanwhile, athletes already continuously collect signals such as heart rate, cadence, power, respiratory frequency, and oxygen saturation using non-invasive sensors.

We investigated whether these signals could be used to predict blood lactate and, specifically, whether nonlinear models outperform traditional linear approaches when modeling the complex physiological response to exercise.

Predict Blood Lactate Non-Invasively

Use continuously measured exercise and physiological signals to estimate blood lactate without relying on repeated blood sampling.

Compare Linear and Nonlinear Models

Benchmark linear regression approaches against decision trees, random forests, gradient boosting, and mixture-of-experts models.

Account for Repeated Testing Days

Model day-to-day differences in exercise protocol and physiology rather than assuming one relationship holds identically across every session.

Identify Importnat Physiological Predictors

Evaluate which non-invasive measurements contribute most strongly to lactate prediction.

CS 1090A Blood Lactate Final Project

Final project deck for the blood lactate estimation analysis, including data exploration, modeling, and results.

CS 1090A Blood Lactate Final Project, slide 1 of 33
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