Most innovative piece of running technology
Reliable method to track load during running outside lab setting
High societal relevance & scientific expertise
years scientific experience
data points analyzed every minute of your run
steps used for testing and validating algorithms
Most running injuries are overuse injuries. They happen when your load exceeds what your body can handle. Safe progression isn’t about avoiding high load, it’s about balancing load and tolerance to prevent injuries and recover smarter.




OnTracx quantifies impact load step by step.
Using a lightweight sensor, we measure the biomechanical load your body experiences during every run. These measurements closely match gold-standard lab metrics, but now they work outdoors, in real life.
This metric represents the average impact peak (Peak Tibial Acceleration, PTA) measured across all steps in a session. It reflects the typical impact your body experiences while running. This value is influenced by running speed, running technique, surface, and more and differs for every runner.
Total load accumulated during a run. Cumulative load is the sum of all impact loads across every step.
How your running load changes over time. Load progression shows the percentage increase or decrease in cumulative load between sessions or between weeks. Monitoring progression helps ensure that load increases gradually and safely, reducing the risk of overload.
Load tolerance or load capacity, indicates how prone a runner is for sustaining an injury.
OnTracx classifies runners into low, medium, or high tolerance using evidence-based factors like age, experience, injury history, and current pain.
With this insight, you can distinguish runners who need to build up load gradually and from those who can increase their load more progressively.






OnTracx translates load and tolerance into individualized, load-based return-to-run programs, designed for smart and controlled progression.
Baseline load represents the load level at the start of a return-to-run program. OnTracx determines it based on pre-injury load and injury information, or it can be set by a professional based on distance or estimated load. It serves as the reference point from which safe progression begins.
Chronic load is the average cumulative load over the past 3 weeks, providing insight into your recent training history.
Acute load represents the cumulative load from the most recent session or week. Comparing acute load with chronic load highlights sudden spikes in load, which are often linked to increased injury risk.
Running speed affects the impact peak at each step, and the effect is highly individual. This makes speed an important factor to consider when progressing running load during rehabilitation.

Built on rigorous research and real-world testing, our technology delivers reliable insights you can trust.
OnTracx is built on biomechanical principles, co-developed with professionals, and validated against laboratory references.
Explore our resources to understand how we measure load and provide actionable insights.

Running distance or duration doesn’t reflect actual mechanical load, which varies with speed, style, terrain, surface, shoes and more. Recent evidence shows that over 70% of injuries occur when load exceeds the body’s capacity. Volume-based rules like “+10% per week” don’t account for individual load and are often ineffective. OnTracx tracks actual load in real-world runs, enabling gradual, individualized training and long-term injury prevention.
Over 70% of running injuries are linked to excessive mechanical load, often from sudden increases. Fitness can improve faster than tissue adaptation, risking overload. Tracking load helps runners and professionals spot spikes, plan safer progressions, and support return-to-run after injury.
The tolerance profile shows how well an athlete’s body handles mechanical load. Calculated during intake, it guides a tailored weekly load progression. Low-tolerance athletes get conservative increases, while high-tolerance athletes progress faster, ensuring safer and more effective training and return-to-run plans. More info available in this article.
The OnTracx sensor measures tibial acceleration (PTA) at foot strike using a lightweight IMU. Algorithms convert this into step-by-step mechanical load estimates, letting practitioners track impact and cumulative load. While not direct tissue force, PTA strongly correlates with lab measures of running load.
No, there’s no single “perfect” running style for everyone. Technique changes can reduce load for some runners but increase it for others, so individual measurement is key. OnTracx tracks mechanical load per runner, helping choose the right intervention while supporting overall injury prevention and rehab. Learn more about how OnTracx helps you prevent overuse injuries in this article.
Absolutely not. If an athlete rarely gets injured, they should keep running as usual. Drastic changes in running style or training can backfire. OnTracx isn’t a quick fix, it provides data to help professionals make personalized, informed decisions for gradual training and injury risk management.
OnTracx sensor measurements strongly correlate with lab-based “gold standard” load measures (r = 0.91). This means that our sensor-based measure is almost the same as the load parameter calculated in lab-settings. As a Ghent University spin-off, we prioritize accuracy and validity of our product.
With intervention screening, you can see how any chosen change affects an athlete’s load. The OnTracx sensor measures load and cadence in real time. Record each condition for at least 60 seconds, then compare results to find effective, athlete-specific load management strategies. More info available in this article.
Mechanical load is measured in “G” units. Average runners experience ~9 G, high-impact runners >12 G, but it varies widely. The load of two runners who run the same distance at the same pace can differ by no less than 15%. OnTracx lets you track load during and after each run for personalized insights. More information about running load available in this article.
Surface, footwear, and running style all influence mechanical load, but effects vary per runner. OnTracx helps you discover which conditions reduce load, giving personalized insights for safer training and return-to-run. Learn more about how OnTracx helps you prevent overuse injuries in this article.
Most apps track distance or pace, but OnTracx focuses on mechanical load (the stress on muscles, tendons, and bones). It measures load step-by-step, showing how much your body experiences per run, how it accumulates over time, and how each run contributes, giving runners a new perspective on training progression that traditional metrics often miss.
Yes. Derived from biomechanics research, OnTracx metrics correlate strongly with lab measures. It’s been used in studies with clinicians, running pros, and academics, and continues to expand its scientific evidence base.
OnTracx tracks step-by-step mechanical load in real outdoor runs over weeks or months, across multiple runners. This lets researchers study training load, behavior, and injury risk in real-world conditions, not just controlled labs.