Rope training involves vigorously undulating one or two large ropes using upper body muscles and stabilizing the body with the lower body and core muscles. It is an extremely popular functional training method used frequently in cross training programs such as CrossFit. Charles Fontaine from the University of Minnesota Duluth and Brad Schmidt from Creighton University in Omaha, Nebraska found that a 10-minute rope interval workout (10 sets of 15 seconds rope waving followed by 45 seconds of rest) increased heart rate to 163 beats a minute and metabolic rate 10 times above rest. Rope training is a vigorous functional training method that develops physical fitness.