Helen is a prototypical CrossFit workout. Like Fran, Jackie and a few other of her sisters, she combines functional movements with an otherwise unmatched level of intensity. Each exercise is completed just as the athlete approaches a level of fatigue that would require a reduction in power. The effort is then transferred to another movement that similarly taxes the exerciser until they move to the next. The shifting of mode enables the unrivaled levels of intensity for which CrossFit is known.
Intensity is the independent variable most strongly associated with the favorable adaptation to exercise.