About Sam Gym
AI-powered fitness tracking that actually learns who you are.
🏗️ Why Sam Gym Exists
Every calorie tracker on the market does the same thing: give you a static daily calorie target based on a formula, then make you scroll through a database to log what you ate. Your body changes. The app doesn't.
Sam Gym was built by a fitness enthusiast who got tired of that approach. The question was simple: what if a calorie tracker actually learned your metabolism instead of guessing it?
Sam Gym uses Bayesian statistics to adapt its weight predictions to YOUR body — not a generic formula. After about two weeks of data, it learns your specific metabolic rate and adjusts daily.
📸 What Makes Sam Gym Different
AI Photo Meal Logging
Take a photo of your plate. AI identifies the food, estimates portions, and calculates calories, protein, carbs, and fat — in seconds. No database scrolling.
Adaptive Weight Prediction
A 6-week weight forecast that uses Bayesian modeling to learn YOUR metabolism. Starts generic, then adapts daily based on real data. Eerily accurate after 2 weeks.
WHOOP & Apple Health
Real-time calorie burn from your wearable. Recovery-aware training recommendations. Heart rate zone analysis. Energy balance updated live throughout the day.
Optimal Performance Window
Uses your wake time, recovery score, sleep quality, strain, and workout habits to pinpoint the exact hours your body is primed to train — different every day.
🔬 The Technology
Sam Gym isn't a wrapper around a food database. It's a metabolic learning engine built on real science:
- Bayesian Adaptive Energy Balance Model (AEBM) — Learns your personal TDEE by comparing predicted vs. actual weight changes. Adjusts daily with a confidence-weighted offset. Requires 2+ logged meals per day to prevent garbage-in-garbage-out.
- Computer Vision Meal Analysis — Multi-model AI pipeline identifies foods, estimates portions using visual depth cues, and calculates macro breakdown. Handles mixed plates, restaurant meals, and home cooking.
- Karvonen Heart Rate Reserve Method — Same method used by WHOOP and Garmin for heart rate zone calculation. Uses your actual resting HR (14-day rolling average) and age-based max HR for personalized zones.
- Circadian-Adaptive Performance Window — Combines peer-reviewed circadian rhythm research (core body temperature peaks, PMC3761508, PMC8425416) with your actual wake time, recovery data, sleep hours, strain, and habitual workout timing to compute daily optimal training hours.
- Real-Time Energy Balance — Live calorie burn from WHOOP or Apple Health, decomposed into BMR, activity, thermic effect of food, and exercise. Not a static estimate — updates throughout the day.
Patent pending on the adaptive metabolic modeling system.
🔒 Privacy Is Not a Feature — It's a Principle
Your body data is yours. Period.
- We will never sell your data to third parties
- We will never use your data for advertising
- We will never share your health information with insurers, employers, or anyone
- All data encrypted at rest and in transit
- WHOOP/Apple Health credentials stored with Fernet encryption
- Profile fields individually encrypted in the database
- You can export all your data anytime
- You can delete your account and all data permanently with one tap
Sam Gym is committed to being a Public Benefit Corporation. That's not marketing language — it's a legal structure that means we're bound to prioritize user benefit alongside profit. Your health data will never become a product.
Read our full Privacy Policy for the complete details.
📱 Available On
Sam Gym is available on iPhone and iPad via the App Store. Free 30-day trial, then $3.99/month. No ads. No data selling. Cancel anytime.
The app integrates with:
- WHOOP — Recovery, strain, sleep, heart rate, real-time calorie burn
- Apple Health — Heart rate, workouts, activity, sleep data
- Apple Watch — Passive heart rate and workout data via HealthKit
Try Sam Gym Free for 30 Days
AI photo meal logging. Adaptive weight prediction. WHOOP integration. No commitment.
Download on the App Store