As we get older, our muscle strength slowly declines - increasing our risk of falls, injuries, and loss of independence. In particular, we rely on our lower body strength for many essential daily activities such as walking and climbing stairs. Strength training can help offset the weakening of muscles, but not everyone has the means (or even the desire) to hit the gym for regular weightlifting sessions.
Researchers at Tohoku University have discovered a solution that requires no equipment, only demands five minutes of your day, and has been shown to improve measures of lower body strength. This promising treatment is new, and yet old - drawing on the centuries-old practice of Rei-ho, a type of daily etiquette originally practiced by samurai.
The findings were published in The Tohoku Journal of Experimental Medicine on August 18, 2025.
In Japan, traditional lifestyles provide numerous opportunities to strengthen the legs through daily activities. Sitting in seiza posture (kneeling on the floor with the legs folded under the body) on tatami mats and using squat toilets are such examples. However, tatami mats are going out of style, and Western-style chairs and toilets are becoming more popular.
One cultural tradition that preserves these behaviors and movements is Rei-ho. Rei-ho emphasizes slow, deliberate, and controlled motions in daily actions such as standing, sitting, and walking. Rei-ho's health benefits had never been scientifically tested until now.
A research team at Tohoku University led by Professor Ryoichi Nagatomi conducted a randomized controlled trial to determine the effects of a Rei-ho training routine. The training group performed a five-minute Rei-ho routine, at least four days a week for three months, consisting of controlled Rei-ho style squats and sit-to-stand movements from a chair. The control group continued their usual routines without new exercise. After three months, the training group increased their knee extension strength by an average of 25.9%, compared with only 2.5% in the control group.
"In particular, knee extension strength--the force used to straighten knees--is a key measure of mobility and daily functioning," says Ayaka Ogasawara, first author of the paper, "These exciting results suggest that Rei-ho may help seniors maintain their independence."
These findings suggest that Rei-ho is more than just cultural heritage--it can also serve as a way to stay fit. Since it just alters how we perform simple daily actions, it can be easily incorporated into modern life without equipment or long training sessions.
"We think it's also valuable that those outside of Japan who want to try Rei-ho would also be able to experience a unique aspect of ancient Japanese tradition in addition to the health benefits" says Lecturer Akira Sato.
While a fall means just getting back up for a young person, it can lead to severe injuries or even mortality in the elderly. This is why it is so important for early interventions that seek to offset the muscle weakening that inevitably happens to each and every one of us as we age.
- Publication Details:
Title: A Traditional Japanese Samurai Movement Rei-ho as a Knee Extension Strength Training: A Randomized Controlled Study
Authors: Ayaka Ogasawara, Akira Sato and Ryoichi Nagatomi
Journal: The Tohoku Journal of Experimental Medicine
