Concentration exercises limit your range of movement to increase the effectiveness of the movement.
- Sit on the end of a flat bench with your feet flat and your legs spread live a V.
- Grasp a dumbbell in your hand, palms facing up.
- With your elbow pressed against your inner thigh just above your knee, curl the dumbbell up towards your chest.
- Slowly return to the starting position.
- Repeat and switch arms.
- Keep all of your body still except the arm you are exercising.