The best average power held for duration; null with no power, no
timestamps, or when the section is shorter.
The best average power for each duration (by default a spread from 1 s up to the section's length), shortest first. Never rises as the duration grows. Durations longer than the section are left out. Pauses longer than 10 s count as 10 s, as in every time-weighted number here.
Optionaldurations: readonly Duration[]
Best efforts by power inside a section:
ride.power.bestEffort(minutes(20)).