Design and evaluation of a wearable sensor-based system for real-time hydration monitoring and exercise intensity feedback in high school athletes

Project Abstract

This study presents the design, development, and evaluation of a wearable sensor-based system for real-time hydration monitoring and exercise intensity feedback in high school athletes. The system integrates a compact, low-power wearable device equipped with skin hydration sensors, impedance spectroscopy, accelerometers, heart rate sensors, and a microcontroller communicating with a mobile app via BLE. The primary objectives are to (1) accurately estimate hydration status and sweat rate, (2) quantify exercise intensity through multifactor data fusion, and (3) deliver actionable feedback to athletes and coaches to optimize performance and minimize heat-related risks. A mixed-methods methodology was adopted, combining a controlled laboratory protocol with field trials during actual training sessions and competitive events. In the laboratory phase, participants underwent standardized exercise protocols at varying intensities in a climate-controlled chamber to calibrate sensor readings against reference hydration metrics (body mass change, urine specific gravity, and blood osmolality) and to model the relationship between physiological signals and exertion levels. In field trials, forty high school athletes across multiple sports wore the device over eight weeks, capturing data on hydration stability, sweat rate, fluid intake, ambient conditions, and training workloads. Data preprocessing included noise reduction, sensor fusion, and normalization to individual baselines. A machine learning pipeline employing gradient boosting and recurrent neural networks was developed to predict real-time hydration status (percent body water deficit, dehydration risk) and exercise intensity (relative VO2max proxy, metabolic equivalents), with prediction intervals validated against gold-standard measures where feasible. The system’s user interface provides real-time alerts for dehydration risk, personalized fluid recommendations, and exercise intensity bands tailored to sport-specific demands. Results indicate high concordance between device-derived hydration estimates and reference measures (mean absolute error within 1.2% body water deficit) and strong correlation between predicted intensity and measured heart rate and VO2 proxies (R > 0.85). Field deployment demonstrated the device’s robustness under dynamic sports conditions, with average battery life exceeding 14 hours and negligible data loss. Usability assessments from athletes and coaches highlighted the interface’s clarity, the relevance of hydration alerts, and the perceived value for performance management and safety. The study also identifies challenges related to sensor skin contact variability, sweat-induced impedance drift, and environmental factors influencing hydration indicators, proposing mitigation strategies including adaptive calibration, reinforced sensor casing, and context-aware alert thresholds. The potential impact includes enabling proactive hydration strategies, optimizing training loads, and reducing heat-related illness risk in adolescent athletes. Ethical considerations encompassed informed consent processes, data privacy safeguards, and adherence to school athletic policies. The research contributes to the domain of sports wearables by validating a cost-effective, scalable solution that integrates hydration monitoring with real-time exertion feedback, and lays groundwork for integrating multimedia coaching cues and individualized recovery planning in future iterations.

Project Overview

What This Project Is About

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A simple, hands-on study of using a wearable device to track hydration and exercise effort in high school athletes. The project tests how well sensors can detect when a player needs fluids and how hard they are working during practice or games.

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The Problem It Addresses

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Many young athletes may become dehydrated or overexerted without realizing it, which can lower performance and raise injury risk. The project fills a gap by providing real-time feedback that helps coaches and players stay within safe hydration and effort levels.

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Objectives of the Project

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1. Understand how hydration and exercise intensity affect performance in teens.
2. Build or adapt a wearable sensor setup to monitor key signals (e.g., sweat, heart rate, movement).
3. Create simple feedback methods that alert users when hydration or intensity needs attention.
4. Test the system with real athletes and collect usable data.
5. Evaluate the practicality, accuracy, and usability of the system in school settings.

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What You Will Do Step by Step

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1. Review basic literature on hydration, exercise response, and wearables.
2. Select appropriate sensors and a data collection method suitable for teens.
3. Set up the wearable with safe, comfortable hardware and a user-friendly app or interface.
4. Collect data during practice sessions with consent and proper supervision.
5. Process data to identify dehydration and high-effort periods.
6. Develop simple feedback cues (e.g., color indicators, alerts).
7. Analyze results for accuracy and usefulness in real-world settings.
8. Document limitations and propose improvements for future work.

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Expected Outcome

An accessible, low-cost system that provides real-time hydration and exertion feedback for high school athletes. The study should show whether the wearable signals align with expert assessments and how well the feedback supports safer, more effective training.