Best efforts

A best effort is the best stretch of a given size inside a section: the highest average power held for 20 minutes, the fastest kilometre. They sit under the measure they are about: power and pace.

Power

import { readFileSync } from 'node:fs';
import { km, minutes, seconds } from '@pond-ts/fit';
import { readActivity } from '@pond-ts/fit/files';

const ride = readActivity(readFileSync('hill-ride.fit'));
const best20 = ride.power.bestEffort(minutes(20))!;
console.log(best20.duration.format(), best20.power.format());
console.log(
  best20.section.label,
  best20.section.bounds.elapsed?.from.format(),
  '→',
  best20.section.bounds.elapsed?.to.format(),
);

20:00 269 W
Best 20:00 58:49 → 1:18:49

Each result hands back the Section it came from, so you can ask that stretch anything else: where it was, what the heart rate did, how it compares.

const where = best20.section.stats();
console.log(
  where.distance?.format('km'),
  where.heartRate.average?.format(),
  where.cadence.average?.format(),
);

7.04 km 162 bpm 81 rpm

curve() gives the best for many durations at once, shortest first. With no durations it picks a spread from one second to the length of the section; or pass the ones you want:

for (const e of ride.power.curve([
  seconds(5),
  minutes(1),
  minutes(5),
  minutes(20),
  minutes(60),
]))
  console.log(e.duration.format().padStart(7), e.power.format());

05 355 W
00 323 W
00 309 W
00 269 W
00:00 221 W

A longer duration never has a higher best than a shorter one. Durations longer than the section are left out, and with no power the curve is empty and bestEffort is null.

Pace

pace.bestEffort(distance) is the fastest elapsed time over that distance, stops included. bestEfforts() takes several, or by default the usual race distances (400 m up to the marathon) that fit inside the section:

const run = readActivity(readFileSync('interval-run.fit'));
for (const e of run.pace.bestEfforts())
  console.log(
    e.section.label.padEnd(10),
    e.time.format().padStart(6),
    e.pace.format(),
  );

Best 400 m   1:31 3:48/km
Best 0.5 mi   3:05 3:50/km
Best 1 km    4:10 4:10/km
Best 1 mi    7:16 4:31/km
Best 2 mi   15:39 4:52/km
Best 5 km   24:49 4:58/km

Inside any section

Best efforts belong to sections, so you can ask inside a lap, a climb or a stretch you picked:

const secondClimb = ride.section({ distance: { from: km(28), to: km(32) } });
console.log(secondClimb.power.bestEffort(minutes(5))?.power.format());

309 W

How gaps and pauses count

A power meter dropout counts as 0 W. A best effort is work over time, and a dropout did no measured work. The ride's best 20 minutes contains its 15-second dropout; Power curve and best efforts shows what changes if you skip it instead.
A pause counts as 10 seconds at most. Each sample stands for the time since the one before, capped at 10 seconds, at its own power. So after a café pause the first sample stands for 10 seconds at whatever it recorded, and the pause adds nothing else. An effort can run across a stop this way: the riding either side of it makes one 20-minute effort, whose section runs longer than its duration. On the example ride, the best hour is made that way.
Pace efforts are on elapsed time. The fastest kilometre includes any time stood still inside it, as a race result would.

Power​

Pace​

Inside any section​

How gaps and pauses count​

Power

Pace

Inside any section

How gaps and pauses count