Multimodal Physiological and Biomechanical Wearable Dataset for Non-Invasive Blood Lactate Estimation

This dataset contains multimodal physiological and biomechanical measurements collected from wearable devices during running experiments aimed at non-invasive estimation of blood lactate levels. The data include time-series and derived variables from heart rate monitors, respiratory sensors, and motion capture systems.The dataset columns are as follows:<b>id</b>: Subject identifier.<b>stage</b>: Experimental stage during the test.<b>speed (km/h)</b>: Running speed, with 0 indicating resting stage.<b>LT</b>: Blood lactate threshold calculated by the Dmax method.<b>BLA</b>: Blood lactate concentration.<b>BLAclass</b>: Exercise load classification based on lactate threshold, where 1 indicates high load (above LT) and 0 indicates low load (below LT).<b>max_hr</b>: Maximum heart rate recorded.<b>LF</b>: Low-frequency power (0.04–0.15 Hz) from heart rate variability (HRV) frequency domain analysis, reflecting sympathetic and parasympathetic interaction. Increased LF power is generally associated with sympathetic activation.<b>HF</b>: High-frequency power (0.15–0.4 Hz) from HRV, primarily linked to parasympathetic activity related to respiratory sinus arrhythmia.<b>BF</b>: Breathing frequency (breaths per minute).<b>BR</b>: Minute ventilation, calculated as the current actual ventilation relative to maximal voluntary ventilation.<b>CI</b>: Cardiac index, i.e., cardiac output normalized by body surface area (m²).<b>EE</b>: Energy expenditure in kilocalories per hour, representing metabolic energy produced from carbohydrates, fats, and proteins.<b>RER</b>: Respiratory exchange ratio, defined as the ratio of carbon dioxide output to oxygen uptake.<b>V'CO2</b>: Carbon dioxide output via alveolar ventilation (L/min).<b>V'E</b>: Minute ventilation volume, equal to tidal volume multiplied by breathing frequency (L/min).<b>V'O2</b>: Oxygen uptake via alveolar ventilation (L/min).<b>VT</b>: Tidal volume, the average volume of air inhaled or exhaled per breath at rest (L).<b>VGRF</b>: Vertical ground reaction force.<b>STEP</b>: Step frequency divided by speed.<b>SWING</b>: Average swing phase duration normalized by speed (s/km/h).<b>CONTACT</b>: Average foot contact time normalized by speed (s/km/h).<b>GAIT</b>: Average gait cycle duration normalized by speed (s/km/h).<b>CONGAIT</b>: Ratio of contact time to gait cycle duration, normalized by speed.This comprehensive dataset supports research into physiological and biomechanical indicators related to blood lactate levels, enabling development of non-invasive monitoring methods during exercise.