FuelFlow
Stop Bonking. Start PRing.
Free · In‑App Purchases
Built for the Dark Miles
FuelFlow is a real-time fueling app for endurance athletes — the ones who know "just send it" stops working past mile 21. Whether you're prepping for your first marathon or your tenth 100-miler, FuelFlow tracks what you're putting in versus what your body is asking for, and tells you when to do something about it.
NEW: ULTRA MODE (EARLY ACCESS)
Build a race plan on the web at fuelflow.run — course, aid stations, pacing, per-phase fueling targets — then race it on iPhone and Apple Watch.
• Aid station tracking: know what's coming and what your next segment needs
• The Stack: an adaptive UI that simplifies as you get deeper into the pain cave, so the right action is always one tap away
• Crew Mode: generate PDF crew cards and share links so pacers and crew know what to hand you, when
• Course-aware fueling targets that respect terrain and pace
• Works offline once your plan is downloaded
Enable Ultra Mode in Settings.
TRACK WHAT MATTERS, IN REAL TIME
Log carbs, sodium, and water as you go — on iPhone or Apple Watch. No mental math at mile 18 or mile 93. Smart status messages tell you whether to fuel now, soon, or whether you're crushing it, based on where you are in the activity — not just hourly goals.
APPLE WATCH THAT ACTUALLY WORKS
Log nutrition without pulling out your phone. Quick Access Grid puts your go-to fuel one tap away. The watch app runs standalone — no phone required. Alerts when you fall behind.
AUDIO COACHING: EYES UP, HANDS FREE (EARLY ACCESS)
Spoken nutrition reminders during activities. Eight crew personalities from zen to drill sergeant.
BUILT FOR ENDURANCE SPORTS
• Running — road, trail, ultra
• Cycling — road, gravel, mountain
• Triathlon and multisport
• Nordic skiing, swimming, hiking, mountaineering
YOUR DATA, YOUR WAY
Export every session: CSV, PDF (with route map and heart-rate graph), TCX, GPX, FIT. Import workouts from Apple Health, Strava, Garmin Connect, or upload FIT files from your bike computer to add nutrition to past activities.
SMART TRACKING FEATURES
• Customizable nutrition goals per sport
• Sweat profile data with H drop data import
• Pre-activity nutrition logging
• Weather and route data
• GI distress and energy level tracking
• Personal records and trend analysis
PRIVACY FIRST
Your health data belongs to you. iCloud syncs privately across your devices. We don't sell your information or share it with third parties.
RACE-DAY TESTED
Built by ultrarunners. Tested at trail 50s, 100Ks, and 100-milers. Sharpened every release.
START FUELING SMARTER
Download FuelFlow and stop wondering if you're doing it right.
Your next personal best starts here.
EULA: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Garmin sync bug fixes. Now even more ultra!
The developer, TheVSG LLC, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Linked to You
The following data may be collected but it is not linked to your identity:
- Usage Data
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- TheVSG LLC
- Size
- 62.6 MB
- Category
- Health & Fitness
- Compatibility
Requires iOS 26.0 or later.
- iPhone
Requires iOS 26.0 or later. - Apple Vision
Requires visionOS 26.0 or later. - Apple Watch
Requires watchOS 26.0 or later.
- iPhone
- Location
- This app may use your location even when it isn’t open, which can decrease device battery life.
- Languages
- English
- Age Rating
4+
- 4+
- In-App Purchases
Yes
- FuelFlow Premium $14.99
- FuelFlow Premium $1.99
- Copyright
- © 2026