One run is a result.
Your history is a pattern.

Fitness: what pace takes out of you.

Your Fitness estimate brings pace and heart-rate effort together. Running faster at a comparable effort can be a sign that your fitness is improving.

The trend helps you look beyond a single good or bad day. Use the run points to inspect the workouts behind it, or compare with an earlier period.

Pace versus effort: compare like with like.

See how your pace relates to your heart-rate effort. Easy runs and hard workouts occupy different parts of the chart; looking at both helps put a quick pace in context.

Select a run for its key numbers. When detailed data is available, inspect the workout structure and interval pace, heart rate, effort and total interval time.

Durability: how well the pace holds.

Fitness tells only part of the story. Durability estimates how much of your shorter-run performance carries into longer efforts at a similar effort level.

A curve that holds up better suggests less fade as duration increases. Recent long runs provide the most useful evidence for longer-duration estimates.

The chart uses a common effort reference for comparison. Your race-goal point uses your expected race effort, so it can sit away from that curve.

An estimate beyond the durations you’ve recently run is an extrapolation. Treat it as a question to investigate, rather than proof that you can hold a pace.

Race goals: put the target in context.

Choose a distance, target time and expected average race heart rate. RunFit estimates the Fitness needed while accounting for the duration and your durability.

Starting values help you get going; adjust them to reflect the race you have in mind. The estimate depends on those choices and on the evidence in your runs. It is not a promised finish time.

Start with what you have. Refine as you go.

Your run history starts appearing as it arrives. Detailed insights fill in afterward. Keep exploring while recent workouts are analyzed in the background.

Set your resting and maximum heart rate in Settings, and keep them accurate. Better heart-rate data and a mix of recent workouts make comparisons more useful.

Not every run can support every estimate. Missing heart rate, unusual conditions or limited long-run evidence can leave gaps. RunFit keeps the evidence visible so you can judge it yourself.