Your body is the engine.
Know exactly what it burns.
Military-grade metabolic science. On your wrist. On your phone.
Coming SoonGeneric fitness apps guess your calories.
Hiko calculates them — using the same metabolic science the US Army uses for its soldiers.
Military-grade metabolic science
Hiko uses the Load Carriage Decision Aid (LCDA) equation published by USARIEM in 2022. Six variables. One precise calorie number.
Every surface has a cost
Paved road, gravel trail, deep snow — each surface changes your energy expenditure. Hiko detects terrain automatically via OpenStreetMap.
The Japanese walking method. In your pocket.
Alternating fast and slow intervals backed by 20 years of research at Shinshu University. Hiko is the first app to combine Japanese interval walking with load carriage science.
Your heart rate tells the story
Heart rate, speed, altitude, terrain — Hiko correlates all four in real time. When your heart says you're climbing before GPS does, Hiko knows.
Your data stays on your device. Period.
On-Device Only
All calculations happen on your iPhone. Nothing leaves.
No Servers
Hiko has no backend. No accounts. No sign-up.
No Tracking
Zero analytics. Zero data collection. Zero compromise.
Your Health Data
HealthKit data stays in Apple's encrypted container.
Built on real research.
Years of interval walking research at Shinshu University
LCDA equation published by USARIEM
Bytes of your data that leave your phone
Based on peer-reviewed research by Looney et al. (USARIEM) and Prof. Hiroshi Nose (Shinshu University, Japan).
Learn how LCDA worksRuck smarter.
Download Hiko.
Frequently Asked Questions
What is LCDA?
The Load Carriage Decision Aid is a metabolic equation published by the US Army Research Institute (USARIEM) in 2022. It uses six variables — body mass, lean body mass, walking speed, terrain, grade, and external load — to calculate precise calorie expenditure. Hiko is the first consumer app to implement LCDA.
How is this different from other calorie trackers?
Most fitness apps estimate calories using weight multiplied by time — a single variable. Hiko uses six variables from peer-reviewed military research. The difference between walking on pavement versus gravel can be 50% more calories. Other apps miss this entirely.
What is Japanese interval walking?
A training method developed by Professor Hiroshi Nose at Shinshu University over 20 years of research with 7,000+ participants. You alternate between fast and slow walking intervals. Studies show improvements in aerobic capacity, leg strength, and metabolic health.
Do I need an Apple Watch?
Hiko works on iPhone alone. Apple Watch adds real-time heart rate, more accurate speed tracking, and wrist-based workout controls. The calorie calculations work either way — the Watch enriches the data.
Is my data private?
100% on-device. No accounts, no servers, no data collection. Your health data never leaves your phone. Hiko reads from HealthKit and writes results back to HealthKit. Nothing is transmitted anywhere.
What terrains does Hiko detect?
Nine terrain types via OpenStreetMap: paved road, dirt road, gravel, sand, grass, swamp, deep snow, light snow, and heavy brush. Each has a scientifically validated energy coefficient from military research.