It's often tricky, especially with large fish. Go ahead and try to pick a 10-pound dumbbell off the floor with a fly rod, fly line and 12-pound test leader. It's almost impossible if you hold the grip normally, gently lift the rod, and expect the flexed graphite tip of the rod to make it happen. When lifting heavy fish, you want to focus the stress into the line itself (trust me, 12-pound Maxima is harder to break than you think) and the butt section of the fly rod. To get that done, you want to grip slightly higher on the cork, bring the reel seat flush against your forearm, and then lift with your arm and shoulder, not just your wrist. This dramatically reinforces the leverage you have on the fish.