As we age, declining physical function and fading memory seem like natural laws. However, a Japanese expert presents a surprising view: if someone has "poor memory but good physical strength," this might actually be a warning sign of cognitive decline. He introduces a simple self-test to gauge brain age and teaches a 30-second squat to help prevent dementia.
Learn the 10-Second Leg Raise Test
Research has uncovered an unexpected connection between thigh muscles and the brain. Japanese dementia prevention expert Teruyuki Motoyama proposes a simple self-assessment method:
- Sit on a chair with your back straight. Alternately straighten each leg parallel to the ground and hold for 10 seconds.
Motoyama explains that people with declining cognitive function often have difficulty feeling pain and fatigue in their front thigh muscles. If you feel no pain at all and think "this is too easy," it could indicate that your cognitive function may be declining. He suggests rating the pain felt in the front thigh during this leg raise on a scale of 1 to 10:
- Pain level 5 or above: Most likely healthy individuals
- Pain level 0 to 3: Those who feel only mild pain may already have dementia or mild cognitive impairment
Why Do People with Dementia Not Feel Pain and Fatigue? Lack of Load is the Main Cause of Decline
This phenomenon reflects sensory nerve degeneration. When muscles are active, they generate weak electrical signals that travel via sensory nerves to the brain, allowing it to perceive pain and fatigue. However, once sensory nerves degenerate, this information struggles to reach the brain. Even with strenuous exercise, the person cannot feel pain or fatigue. "This is why dementia patients can wander around for hours without feeling tired—their sensory nerves have degenerated, and their brains cannot perceive fatigue."
Even people with normal cognitive function can see their dementia risk increase after just two weeks of hospitalization, precisely because they are unable to move their bodies. Global research confirms that dementia patients are concentrated mainly in modernized, advanced nations, while ethnic groups that continue traditional lifestyles where their bodies regularly bear physical load have almost no dementia issues.
30-Second Squat Reconnects the Brain and Nerves
Through large muscle training, the brain can be rejuvenated. "Reading and conversation only stimulate the brain indirectly. The only thing that can stimulate the brain directly is physical muscle activity." Motoyama emphasizes that by fully engaging muscles and retraining sensory nerves, you can "reconnect" the nerves. For those with mild cognitive impairment or early-stage dementia, there is a real chance for improvement. Motoyama recommends the simple "30-second squat" method:
30-Second Squat for Dementia Prevention | Steps
- Stand with feet about 1.5 times shoulder-width apart (aim for over 60cm), toes pointing outward at a 45-degree angle.
- Bend your knees and hips to squat down about 20cm.
- Do not fully stand up; return to a point about 10cm above the starting position.
- Perform at a pace of one squat every 3 seconds, completing 10 squats within 30 seconds, repeating steps 2 and 3.
30-Second Squat for Dementia Prevention | Frequency
- As a guideline to avoid muscle soreness, doing this once every two days to once a week is sufficient.
- Motoyama notes that you don't need to be fixated on the exact number. It's better to focus your concentration fully on the muscles while completing 10 reps, as this provides much stronger stimulation to the brain. If you still have energy after 10 reps, you can increase to 20. Be especially cautious: those with dulled sensory nerves will have greater difficulty feeling fatigue, so do not increase the number of reps excessively. If it feels too strenuous, you can squat shallower. If you experience discomfort in your knees or hips, don't force it; simply maintaining a position with your hips sticking out for 10 seconds can also yield some effect.
Results Seen in 3 Months; Combining with Lifestyle Improvements Yields Better Results
For those in the early stages of mild cognitive impairment who perform these squats, improvements in sensory nerves can be seen after 2 to 3 months. However, Motoyama emphasizes that to achieve maximum effect, lifestyle habits must also be improved:
- Avoid Accumulating Stress: Stress leads to excessive cortisol secretion, which can cause the hippocampus to shrink.
- Ensure Adequate Sleep: Lack of sleep allows amyloid beta, one of the causative substances of Alzheimer's disease, to accumulate more easily in the brain. Aim for at least 7 hours of sleep per day.
