OptionalendOptionalstartInclusive sample range of the window that achieved it — for focusing the
chart/map on where the effort happened (maps to distance/time via the
prepared cum / timeSec). Carried through from the powerCurve
point; absent only if no window qualified.
Best average power sustained over any window of this length, watts.
OptionalwattsPower-to-weight, when a body weight (as of the activity date) is known.
One row of the power best-efforts table.