New Rochelle, N.Y. — October 20, 2026 — Millions of people rely on smartwatches, fitness trackers and apps for tracking calories burned. But how accurate are those numbers? Independent research has repeatedly found that calorie-burn estimates from popular fitness trackers and apps can be wildly inconsistent. They can be off by as much as 93% in controlled testing against medical-grade equipment (1). The Difference, a weight management app known for its predictive, data-driven approach, announced today a major update. The update comes during National Health Education Week and involves Activity Burn. Its library of official physical activities now reflects the most current exercise science available. In addition, its search and validation systems for user-added activities have been substantially upgraded.
Database Updated with New Compendium
The update refreshes the app’s activity database against the newest edition of the Compendium of Physical Activities. The Compendium is the standard for scientific reference research used to assess intensity levels for activities. The Compendium assigns Metabolic Equivalent (MET) values to physical activity, from walking, running and treadmill workouts to household chores (2). The revision added hundreds of newly standardized activities, and updated the intensity ratings on hundreds more, some by significant margins.
Alongside the database refresh, The Difference’s latest app release improves the matching algorithm that powers its Activities Search. Users can now find and log the right activity faster when counting calories burned. The app also adds new validation checks for user-submitted activities in its crowd-sourced database as the community adds new entries. The user added workouts and movement types are not part of what the official research covers. These entries are measured against existing standards for both naming and intensity accuracy before they reach other users.
“Regular movement, activities of everyday life, and structured exercise can and should be a part of everyone’s life. At The Difference, we know that accurately measuring the impact of physical exertion, at any level of intensity, is helpful for our clients, particularly those with weight management goals,” said Peter Conroy, Founder and CEO of The Difference and a Certified Personal Trainer (CPT) through the National Academy of Sports Medicine (NASM).
New Data Improves Activity Burn
The timing reflects a broader shift in the company’s approach. A typical calorie burn calculator or heart rate–based estimate relies on generic formulas to estimate calorie burn. In contrast, The Difference’s premium Activity Burn feature layers each user’s individual profile on top of standardized MET data. It aims to close the gap between what a tracker reports and what a person’s body actually does.
For people looking for the best way to track calories burned during exercise, personalization matters. Activity Burn uses a user’s weight, height, gender, and age to personalize the intensity of whatever they are doing. As opposed to applying the fixed constant built into traditional MET formulas, which treat every person the same. In one example from The Difference’s own analysis, a generic estimate for a single bike ride showed 787 calories. In contrast, Activity Burn personalized the rider’s profile and showed 502 calories. This is a difference of nearly 300 calories from one workout.
Even small errors compound. Someone trying to lose weight could overeat by 100 to 150 calories a day by overestimating their activity burn by 20% to 30%. Activity Burn works alongside True Burn, The Difference’s formula that learns a user’s real daily calorie burn. These features help users can see what they’ll weigh tomorrow based on what they eat and do today. Activity Burn is part of The Difference’s Premium subscription, available on iOS and Android for $24.99 a year.
About The Difference
The Difference is a New Rochelle, NY-based weight management company dedicated to improving the quality of life and increasing the longevity of its customers and communities. Its app combines proprietary predictive weight-change formulas, a food database of more than 1.5 million items with full macro breakdowns, AI-powered food-photo recognition, smart scale integration, and personalized weight forecasting with an activity-tracking system built on current exercise science. The Difference seeks to make lasting improvement in the health and wellness of its clients and communities with predictive, intuitive, and affordable weight management technology, and has prioritized partnerships that extend that mission into underserved communities. More information is available at www.thedifferenceapp.com.
Media Contact:
Peter Conroy
The Difference
thedifferenceapp@gmail.com
+1-718-801-7563
(1) Shcherbina A, et al. “Accuracy in Wrist-Worn, Sensor-Based Measurements of Heart Rate and Energy Expenditure in a Diverse Cohort.” Journal of Personalized Medicine, 2017. https://doi.org/10.3390/jpm7020003.
(2) Herrmann SD, et al. “2024 Adult Compendium of Physical Activities.” Journal of Sport and Health Science, 2024. https://doi.org/10.1016/j.jshs.2023.10.010.
