An excerpt from Black Belt Magazine 1970 Yearbook
The fourth black belt magazine Survey has revealed a slight decline in the number of karate practitioners as compared to last year. Since the inauguration of this annual survey, this is the first time that karate membership has declined and the first time judo has overtaken the total enrollment of karate.
According to the United States Judo Federation, the total registration for judo in 1969 was 127,000 and the newly formed United States Judo Association claimed another 12,000 members for a total of 139,000 participants in judo. But some USJA members also belong to the USJF, and if the members who belong to both organizations were discounted in one of the organizations, total judo membership in the U.S. would be approximately 135,000.
The USJF membership has grown primarily in the junior and white belt divisions. According to this organization, 5,000 additional juniors were added to the roll in 1969, and another 4,700 white belts as well as brown belts joined the federation in the same year. But the black belt division showed an increase of only 300. The USJA had a total of 12,000 registered members in 1969, consisting of 900 women, 500 black belts and 7,000 juniors below the age of 17 years old.
The year 1969 is the year karate ceased to grow and began, in fact, to falter. The art was not only surpassed by judo, but more participants abandoned their karate dojo than new students who joined. Until last year when the pace began to slow, karate had showed a growth trend, but 1969 finally revealed a decrease in participants from 130,000 to 123,000—a loss of 7,000 enthusiasts.
See also this previous study.
This page is provided by Neil Ohlenkamp, author of Judo Unleashed. Last modified December 1, 2006.