C. Layton et L. Avenell, Time taken as a determinant of advancement in Shotokan karate black-belt Heian kata performance, PERC MOT SK, 89(3), 1999, pp. 1110-1110
30 experienced black-belt subjects were individually timed on each of the f
ive Heian kata. Significant relationships were found between years of train
ing and increased performance time on all the kata and for four with age co
ntrolled. The multiple correlation was significant.