Mike Mentzer shares details of his body part training and then talks further about “Heavy Duty” training principles.Source: MuscleMag International (May 1985) Page #81 - MuscleMag International (May 1985) Page #82 - MuscleMag International (May 1985) Page #83 - MuscleMag International (May 1985) Page #84 - MuscleMag International (May 1985)