How it works.
Your heart rate sets the pace, not a stopwatch, and not a plan written for someone else's body.
Your easy ceiling, set from you.
During setup, First Gear works out your easy ceiling from your age and resting heart rate: the heart rate where effort stops being easy. Stay under it and you're working at the right effort, whether that's a walk or a jog. As your fitness improves, the ceiling moves with you. No fixed pace, no stopwatch deciding for you.
The talk test.
After a run interval, the coach asks one question: could you have held a conversation just then? Yes, no, or not sure. Your answer nudges the ceiling up or down. It's a second signal alongside your heart rate, so the plan is tuned to how the effort actually felt, not only to a number on your wrist.
Week one, you only walk.
Three twenty-minute walks, nothing more. The coach uses them to read your resting effort and to teach you what easy actually feels like, which most people over 40 have never had the chance to learn.
Run intervals come from your heart, not a clock.
From week two, short run intervals appear, but they're triggered by your heart rate, not a timer. Ease into a jog, and the moment your heart rate nears the ceiling, the coach brings you back to a walk. Over the weeks the intervals lengthen as your data says you're ready, and walking stays part of every session.
The plan adapts. You don't have to.
Have a hard session, or come back after a break, and the coach holds you at your current stage until your numbers say you're ready to move on. After more than a couple of weeks away, it steps back a stage and eases you back in, rather than picking up where a calendar says you should be.
Your safety net.
If your heart rate stays very high for a sustained stretch, the coach tells you to stop, not just to ease off. If you take beta blockers, tell First Gear during setup. The app turns off the age-based formulas and relies on the talk test instead, since medication changes how your heart rate responds to effort. First Gear is coaching guidance, not medical monitoring. If you have a heart condition, or you're unsure about starting exercise, talk to your doctor first.