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What Is Isotonic, Isokinetic, Isometric and Auxotonic Training?
What is Isotonic Training? Which exercises can be given for Isotonic Exercising?
This is a relatively easy question to answer, but I wanted to expand on it as well. There is no other field that seems to be as susceptible to marketing than the fitness industry. We see it every day with infomercials, supplement ads, and muscle magazines. The problem stems from the fact that many of these companies try to use big scientific terms to get the consumers to believe their product is superior. In fact, very few of these companies use true science or even understand the science they are promoting. This is where spending time with true text books can be very helpful in cutting through all the garbage.
Now, there are several forms of lifting... isotonic, auxotonic, isokinetic, and isometric. Here is a brief defination of all.
Isotonic - where there is constant tension during the lift
Isokinetic - constant velocity (speed) in the lift
Isometric - there is no change in muscle length during the lift, static
Auxotonic - changing tensions caused by altered velocities and joint angles
Isotonic lifting never really occurs. Many of the classic machine manufactorers would like us to believe that they have created equipment that places the same level of tension throughout the entire movement. The cams that have been created still do not meet everyone's strength curves. They base all their work on theoretical averages that by its own definiton is not going to meet the needs of many individuals. Even during free weight training the tension is not constant as we naturally move the weights with varying speeds and the fact that our joints are moving will cause a 50 pound dumbbell actually to vary in weight.
Isokinetic machines used in many rehab clinics are also misleading. The theory of moving with a constant velocity is both faulty and dangerous. First, nothing moves with a constant velocity, especially weight training. The weights have to be accelerated and decelerated, even in these isokinetic machines!
Auxotonic movement is the most common in sport and training. Because we often have to move an object from inertia and we have to decelerate the weight near the end range of motion to protect the joint. This is often what occurs in sport as well. We often have to accelerate very quickly and equally important have to learn how to decelerate quickly. It is interesting to note that most injuries do not occur with ballistic actions that many so called "experts" would like you to believe. Most injuries occur when one is trying to overcome inertia or does not have the eccentric strength to decelerate properly.
This is why it is so important to understand science versus marketing!!