Exercise 1: Flat bench press (which trains Pectoralis major). As you lower the bar towards the chest is the eccentric phase of the movement, as you raise the bar back up is the concentric phase of the movement. The isometric phase is when no movement occurs. If you perform the bench press exercise in a slow and controlled manner, I would say there are two isometric phases: the first one is when you have lowered the bar to chest and right before you start pushing it up again (at the end of the eccentric phase). The second isometric phase is at the lockout position when you hold the bar at arm''s lenght, right before you start lowering the bar (at the end of the concentric phase).

Exercise 2: Pull upp (which trains the muscles of the back, for example Latissimus dorsi). Pulling your upper body towards the bar is the concentric phase. As your chin reaches the position that it is elevated to the bar, you might hold it in the top position for a second before you start lowering your body. This top position is the isometric phase of the movement. When you lower your body in a controlled manner is the eccentric movement. The muscle is strongest in the eccentric phase (lowering the body). …show more content…
As you press the dumbells towards the ceiling is the concentric phase. To stop just short locking the elbows and holding the weights in the top position is the isometric phase. The eccentric phase occurs while you are descending back to the start position (lowering your