In order to compare the true fitness-raising impact of karate, scientists at Adelphi University in the United States recently asked 11 subjects to participate in two randomly assigned trials preceded by a minimum of three learning trials. One of the trials consisted of karate exercise, including a fairly continuous, rhythmic series of kicks, blocks, and punches. The other trial was simply a typical low-impact aerobic-dance routine.

There were few differences between karate and aerobic dance. Heart rate settled at 157 beats per minute, and oxygen consumption and ventilation rates were almost identical in the two activities. The only significant different was that the karate movements stimulated an increase in carbohydrate metabolism, while the aerobic dance relied more on fat.

It's fair to say that continuous karate exercise provides a fine cardiovascular stimulus and can produce valuable improvements in aerobic capacity. In fact, the gains are probably as great as those achieved through more traditional forms of exercise like aerobic dance.

('The Energy Requirements of Karate Aerobic Exercise Versus Low Impact Aerobic Dance,' Medicine and Science in Sports and Exercise, vol. 26(5), Supplement, p.510, 1994)