What is a critical rule when performing a one arm row regarding the bar's motion?

The critical rule when performing a one-arm row is not to bounce the bar off the chest at any time. This is important because bouncing the bar can lead to poor form and an increased risk of injury. Effective resistance training relies on controlled movements to isolate the target muscles and ensure proper engagement throughout the exercise. Bouncing can create momentum that diminishes the workload on the muscles, reducing the effectiveness of the exercise and potentially leading to improper lifting mechanics.

Additionally, maintaining controlled motion helps maintain focus on muscle contraction and ensures that the correct muscles are being targeted effectively. This principle is paramount in promoting strength gains and achieving optimal results from the exercise. Adhering to this rule allows for better form, enhances muscle activation, and promotes safety during resistance training.