Power curve (mean maximal power)

Your power curve — also called the mean maximal power (MMP) curve — plots the best average power you've produced for every duration, from one second out to several hours. Read left to right it falls steeply through the sprint durations and flattens toward your threshold. Its shape is a fingerprint of what kind of rider you are, and it's the raw material for estimating FTP, Critical Power, and W' without a formal test.

MMP(t) = max rolling-average power sustained for duration t
    (taken across your entire ride history)

The curve is built by sliding a window of each length across every ride and keeping the single best value at that duration. The result is an envelope, not any one ride: your best 5-second sprint and your best 3-hour effort almost certainly came from different days. Handling gaps and dropouts correctly (regridding the stream to a steady sample rate) matters, because a naive window can understate power on rides with pauses or missing data.

The shape reveals rider type. A pure sprinter shows enormous short-duration power that drops off a cliff; a time-triallist posts modest sprint numbers but a nearly flat curve out to an hour. The steepness between roughly 1 and 20 minutes reflects anaerobic capacity (a large W') versus aerobic endurance (a high CP), and comparing your curve against normative power-profile charts locates your strengths and weaknesses.

Because it captures maximal efforts across durations, the curve is what lets models estimate FTP (e.g. ~95% of best 20-minute power, or via the CP model) and fit CP and W' — no dedicated test day required. The important caveat: the curve is only as good as the efforts in it. If you've never gone genuinely deep for 5 minutes, the model has no anchor there and will underestimate that part of your ability.