Exercise, much like the participants who perform it, comes in many shapes and sizes. Toning tables, also known as passive-exercise machines, are a type of resistance training found at specialty salons and some health clubs. You lie on the bench and try to resist the movements of the machine to increase your muscular strength. These tables have a benefit in physical rehabilitation after joint surgeries to improve flexibility. However, if your goal is to improve your muscular strength or lose weight, you have to exercise actively, not passively.
Muscles respond with strength improvements when they contract against a resistance that causes fatigue and are exercised through a full range of motion. For example, when you hold a heavy dumbbell in each hand with your arms straight and your hands in front of your legs, then bend your elbows and raise your hands to your shoulders, you strengthen your biceps. This requires effort, as you move weight against gravity, which contracts your muscles and leads to gains in strength. In contrast, when you lie on a table and the machine moves your arms, you are not using effort, gravity or muscle contraction to perform the activity. A study published in the "Journal of Strength and Conditioning Research" in August 2005 confirms this. Women exercised on passive-motion machines for 16 weeks and were tested for gains in strength and flexibility and also for changes in body composition. The results showed the toning tables did not provide enough stimulus for significant improvements.