Built for the people
who don't run yet.
Most running apps are built for runners. Just5K is built for the person who Googles “how to start running” at midnight and quietly closes the tab.
What Just5K is.
Just5K is a running app for complete beginners — people who have never run before, or who tried Couch to 5K and quit in week 2. The plan starts with mostly walking, gradually adds short running intervals, and over six weeks builds you up to a continuous 5K.
It uses your heart rate from Apple Watch (or your phone) to calibrate intensity in real time, adapts when you miss a day, and translates everything into plain English. No zone charts. No training-load graphs. Just clear guidance on what to do today.
How it works.
Four ideas the app is built around.
Starts where you actually are.
First workout is mostly walking with short running bursts. That's not a compromise — it's the science. Walk-run intervals are the most proven method for building running endurance safely.
Adapts when life happens.
Miss a workout? The plan recalibrates. Take a week off? It meets you where you are, not where you left off. No guilt, no "you're behind schedule" messages — just: here's what to do next.
Speaks plain language.
No VO₂ max, no training load, no jargon. Five simple statuses tell you where you stand: On Track, Crushing It, Rest Up, Getting Back, Lace Up. You always know what to do today.
Protects you from yourself.
Beginners tend to do too much too soon — the number-one cause of injury. Just5K reads your heart rate to know when you're pushing too hard and tells you to rest. "Rest Up" isn't a failure state.
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Your first 5K starts here.
Walk-run intervals, heart rate zones, and a plan that adapts when life happens.