PHA training or Peripheral Heart Action Training is a form of bodybuilding circuit training that was popularized by former Mr. America and Mr. Universe Bob Gajda in the 1960s.
This method is specifically designed to keep the blood circulated throughout the body during the entire workout. The smaller muscles around the heart are worked on first before the larger muscles around the body's periphery.
John McCallum, the noted physical culture writer, wrote several articles concerning P.H.A. in his series The Keys to Progress. McCallum advocated P.H.A., running, and a high protein/low carbohydrate diet for maximum definition, improved endurance, and sound health.