With the sizzling summer heat replaced by cool breezes and mild temperatures recently, it's a great time to contemplate adding a new exercise to your weekly routine. If you are interested in a homegrown sport that is recreational and relieves stress, sports chanbara lets you kill two birds with one stone . . . or one sword.

Sports chanbara is an increasingly popular sport in Japan and abroad in which you try to whack your opponent using special air-filled soft sticks. It was invented in the 1970s by Tetsundo Tanabe, a security company executive from Yokohama. A longtime kendo teacher, he hit upon the idea of creating a new competitive sport out of chanbara, a Japanese-style sword fight often seen in samurai TV programs and popularly imitated by children using plastic toy swords.

Tanabe says he has worked hard to keep the sport — usually referred to by its nickname, "spochan" — free of rigorous rules or manners, after seeing many attempts to promote the highly regulated kendo fail overseas.