On the next round, work the opposite muscle group of the first round. Each repetition involves a concentric and eccentric phase. Slow and controlled movements during each phase provide the most benefit and leads to fewer injuries. It promotes strengthening through the movement pattern. Fast movement can limit the force experienced at certain areas because the movement carried it through.
Controlled movements lead itself to experiencing consistent stress.
Holding your breath increases the pressure within the chest cavity and affects the flow of blood. The heart pumps harder and the blood pressure elevates as a result. Through the range of motion. The joint should be moved through its full range of movement without locking out the joint. Locking out means that only the joint is supporting the load.