T1D Logbook

Beta Cell Foundation

About this app

Exercise is one of the hardest things to manage with type 1 diabetes. A steady jog can send you low; a hard sprint or heavy lift can push you high. T1D Logbook helps you see why — by putting your glucose, insulin, carbs, and heart rate on one shared timeline around each workout, so patterns you could never feel suddenly become obvious.

This is a visualization and reflection tool, not a dosing advisor. It won't tell you what to do — it helps you understand what happened, so you can walk into your next workout better prepared and have richer conversations with your care team.

WHAT YOU CAN DO
• See every workout on one timeline — your real glucose readings shown as dots, with modeled lines for how insulin, carbs, and exercise were each pushing your blood sugar up or down at that moment.
• Compare combined and expanded views — overlay everything on a single chart, or break it into separate stacked charts for glucose, heart rate, insulin, and carbs.
• Pinch, zoom, and scrub across the whole window — from three hours before the workout to three hours after — with every chart staying in sync.
• Filter and search your history — by exercise type, time in range, intensity, and how you felt, plus free-text search across your own reflections.
• Log what mattered — insulin (bolus and basal, for MDI, manual pump, or automated-delivery setups), carbs with protein and fat, and glucose readings — then edit them anytime.
• Write reflections — the most valuable part of tracking. Note what worked, what surprised you, and what to try next time.

WORKS WITH YOUR DEVICES
• Health Connect — reads your workouts and their distance, elevation gain, and calories burned, plus your heart rate and glucose, to build the timeline and stats for each session. Writes back the insulin, carbs, and glucose you log. With your permission it also reads workouts older than 30 days, so the history you already have is there the day you install — patterns in type 1 diabetes take months, not weeks, to see.
• Dexcom — readings flow in automatically through Health Connect.
• Freestyle Libre — connect through LibreLinkUp right in the app.
• Phone, tablet, and Wear OS — a roomy two-pane layout on tablets, and quick glucose, carb, and bolus logging from your wrist.

SHARE WITH YOUR TEAM
Export any workout as a clean PDF or image — in US Letter or A4 — to bring to your endocrinologist, coach, or diabetes educator.

YOUR DATA STAYS YOURS
We don't collect or sell your data. It stays on your device and in your own Google account backup — never sent to us. LibreLinkUp credentials are stored encrypted and used only to talk to Abbott's servers.

GROUNDED IN THE SCIENCE
The modeled curves mirror the physiology in the Beta Cell Foundation's public education material and simulators, so what you see stays consistent with how exercise, insulin, and food actually behave.

IMPORTANT
T1D Logbook is for education and reflection only. It is not a medical device and does not provide medical advice, diagnosis, or treatment. Always work with your healthcare provider for decisions about insulin, food, and exercise.

Free and open source, built for the diabetes community by the Beta Cell Foundation.

What’s new

Beta Cell Lab Notes 1.2 — an accessibility release.

• Light and High Contrast appearances, in Settings
• Every chart line has its own style, so insulin, carbs and basal no longer rely on colour
• TalkBack reads and explores the charts; zoom and scrub without a pinch
• Text and controls grow instead of clipping
• Wear OS: every control named, bigger targets, screens that scroll

Not a medical device — never for dosing decisions.