Air casan a ' cuideachadh dhut obrachadh a-mach an do chuibhreann de buidheann-air a h-wrist.
Faigh a-mach an leth freagarrach cuibhreannan de na bodybuilder around the circumference of the wrist, the calculation tha e air a dhèanamh a-rèir an diabhal na McCallum.