All Slendertone products use clinically proven EMS (electrical muscle stimulation) toning technology, which works by sending signals to your nerves to contract and relax your muscles, similar to regular toning exercise.
When you first turn it on, the feeling may be a little strange as you are at the lowest setting. As you increase the intensity, the sensation goes from a mild tingly feel, to a distinct muscle contraction. This is when the product (and you!), are working to the optimum!
The muscles simultaneously contract and then relax similar to the regular muscle contraction experienced during normal exercise. You can now feel the Slendertone Sensation and your muscles are working. This sensation is powerful enough to recruit all of the muscle fibers in the targeted region, yet comfortable enough to have a conversation while using it.
Be sure to increase the intensity during your toning session so you always feel the Slendertone Sensation; remember there are at least 99 levels.