He trotted round half a lap, took one or two sprints, then some breathing exercises.
他小跑了半圈， 进行了一两次冲刺， 然后进行了一些呼吸练习。
英语百科
Lap joint
（重定向自Half lap）
Halving lap joints are used extensively in traditional timber framing, construction and cabinetry for framing. They are quick and easy to make and provide reasonable strength through good long grain to long grain gluing surface. The shoulders provide some resistance to racking (diagonal distortion). They may be reinforced with dowels or mechanical fasteners to resist twisting.