The barbell wrist curl is an isolating exercise that strengthens the forearms and muscles within the hands while simultaneously improving flexibility.
Sitting on a bench, grab a barbell with your palms facing up and your hands shoulder-width apart. Rest your forearms on your thighs, and allow your wrists to hang over your knees. Perform the movement by curling your palms and wrists toward your face.
Pause for a moment in the top position, then slowly return the barbell to the starting position.
To maximize each rep, perform the movement in a slow and controlled manner.
Avoid cutting the reps short. Focus on moving through the full range of motion with each rep.