CarbTrail: a fuelling plan built from your actual route.
view on the app store ↗ ios · iphone & ipad
Plan your fuel by route, not guesswork. Get a minute-by-minute carb timeline, then mix your own sports drink for a fraction of the cost of a branded one.
Import a route, get a plan
Import a GPX file from any route planner or device, or enter distance and elevation manually — CarbTrail derives duration and effort automatically. Live weather for the route's location, from Open-Meteo, feeds into the plan too, so a hot exposed climb gets a different fluid target than a shaded flat one.
A minute-by-minute schedule
The result is a fuelling and drinking schedule down to the minute, tuned to your body weight, sport, intensity, sweat rate and the weather on the day. Carbohydrate, fluid and sodium appear per hour as bars alongside a fuelling curve, so it's clear at a glance where the plan asks the most of you.
Mix your own drink
A DIY recipe engine gives exact gram amounts of carbohydrate and electrolytes such as salt for a sports drink you mix yourself, together with a cost per bottle and a running tally of what that saves against branded products. A "which mix?" guide compares four carbohydrate systems and two salt sources for anyone starting from scratch. A learn section explains the sports-science background, with sources including ACSM/AND/DC 2016 and Jeukendrup.
- Works for cycling, running, marathon race day, trail running, triathlon, gravel and hiking
- Apple Health integration for athlete-profile data, read and written only with permission
- Four tabs: Plan, Recipe, Learn, Settings — fully in German and English
- Hydration target of about 75% of sweat loss, with a safety margin for long or hot sessions
- Units switch automatically by region (°F, lb, mi, ft where relevant)
CarbTrail calculates reference values for endurance fuelling — it does not replace individualised sports-nutrition advice, particularly for medical conditions or specific performance goals. Digitalbucht is the sole proprietorship of Emil Deak, based in Wülfrath, Germany.
Data and privacy
Location is used only for the weather feature — including automatically right after a GPX import, where the coordinate comes from the route rather than your device. Only coordinates go to Open-Meteo, never profile or health data. Your athlete profile (body weight, biological sex, sweat rate, sweat sodium) stays on the device and is never transmitted. Health data is read or written only with your explicit permission and stays inside Apple Health. No adverts, no tracking.
Full terms of use and privacy policy for all apps: Apps: terms & privacy.
More: all apps · RoadFitter, another app for cyclists.
Last updated: August 2026
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