Research backed strength training and fitness equipment used by top trainers and professional sports teams worldwide. Keiser has always been the training equipment of choice for discerning commercial fitness clubs and organizations. It's non-intimidating style and ease of use are only one part of the reason. There are also the over a hundred peer reviewed and published studies showing how Keiser's Pneumatic Technology provides a safe and effective way for users to get results. That’s why Keiser equipment was invented to provide high resistance with very little inertia (moving mass) and without the dependence upon gravity. The elimination of a weight stack reduces the mass; therefore the force due to acceleration is virtually eliminated, which leaves only pure variable resistant force.