Joseph Pilates was a robust character who believed strongly in his method which he dubbed "controlology".  The first noted event that demonstrated the power of his exercises was in WWI when he and others were detained in prison camps and they survived the 1918 flu epidemic.  He later went to work caring for the war wounded and was able to rehabilitate those in hospital beds and wheelchairs by strengthening their "powerhouse" muscles with his apparatus. 

Later he moved with his wife Clara to New York City and opened a studio that was discovered by famous Dancers and Athletes, including boxer Max Schmelling who was infamous for his fight with Joe Lewis in 1925. 

"Pilates" exercises emphasize balanced development of the body as a whole, through core strength, flexibility, breathing, concentration, and precision.  It has been described as a type of "moving meditation".  Other lessor known benefits include increased stamina and improved circulation.

Using the "Reformer" can assist you in understanding how the exercises work and their relationship to your body.  The increased awareness becomes very useful in improved posture and breathing as well as targeting areas of muscular imbalance that may create pain.  In addition, the "Chair" and "Tower" greatly tighten the mid section improving overall function and providing the trim "physique"!