Isometric exercise has been around for decades. Actual training practices can be traced back to the Roman and Greek times however first identified in the 1920’s. Scientists studied isometric training extensively since the mid-1940 when Hellebrandt discovered that controlled, high muscle tension generation increased muscle strength to high levels quickly. This discovery went mainstream by way of Charles Atlas promoting and selling his program “Dynamic Tension Method”. In 1953 Hettinger and Mueller’s classic paper was first published. Their research conceded: “A maximum muscle strengthening effect was produced by (ONE) daily isometric contraction, lasting six seconds, using an effort level of two thirds of the muscle’s contractile power” Also please refer to our referral/testimonial page for more proof regarding the efficacy of isometric training using the PeakFitPro. I stand 100% behind the results achieved by individuals properly using the gym and following the protocol.