TOKYO — “And now we move on to level two!” calls out a male voice. Then, over some cheerful piano notes: “We’re marching in place! Now, one by one, bring your knees up to your chest. Yes, just like ...

One of the keys to a long and healthy life might be as simple as a five-minute Japanese workout. This low-intensity routine is still practiced by millions of people of all ages in Japan. Here's what ...