Dynamic tension

"Dynamic Tension" is the name Charles Atlas gave to the system of physical exercises that he first popularized in the 1920s.

Dynamic Tension is a self-resistance exercise method which pits muscle against muscle. The practitioner tenses the muscles of a given body part and then moves the body part against the tension as if a heavy weight were being lifted. Dynamic Tension exercises are not merely isometrics, since they call for movement. Instead, the method comprises a combination of exercises in three disciplines: isotonic, isokinetic, and some exercises in the isometric discipline.

Proponents assert that it is nearly impossible to be injured during exercise using this method because one's own muscles provide the force and, as they tire, so the force used also decreases. Likewise, the benefits can continue beyond the more traditional exercise methods because as the practitioner grows stronger, the exercise becomes more intense.

"Dynamic Tension" is a registered trademark of Charles Atlas, Ltd.

After being bullied as a child, Charles Atlas joined the YMCA and began to do numerous exercise routines. He became obsessed with strength. He said that one day he watched a tiger stretching in the zoo and asked himself "How does Mr. Tiger keep in physical condition? Did you ever see a tiger with a barbell?" He concluded that lions and tigers became strong by pitting muscle against muscle. The story may be apocryphal, but it captures the essence of Mr. Atlas' innovation. There were many other "isometric" courses available at the time and it wasn't until Atlas used an advertisement depicting a bully kicking sand in the weakling's face that the sales took off. Some other notable users of this method include Joe DiMaggio, Max Baer, Rocky Marciano, Joe Louis, Robert Ripley and Alan Wells.

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