What causes fatigue? Japan researchers examine “body rust” and recovery

Summary

The report examines fatigue as a widespread issue in Japan, noting that about 80% of survey respondents said they experienced it. Researchers describe fatigue as more than ordinary tiredness: repeated strain may contribute to oxidative stress—likened to “rusting” in the body—and inflammation that can affect the brain. In this state, fatigue may persist even after sleep.

The video also explores ways to monitor fatigue and support recovery, including research on hydration and exercise, workplace measurement tools, and changes to daily habits.

Strategies and techniques discussed

• Support recovery after exertion: Researchers are studying hydration methods and a drink intended to help prepare the body for exercise and speed recovery, including in hot weather.
• Consider polyphenol-rich foods: The report mentions polyphenols in foods and drinks such as red wine, tea, and coffee. Professor Watanabe’s research highlights cocoa polyphenols in relation to fatigue recovery.
• Track fatigue objectively: A transportation company measures drivers’ fatigue before work and uses the results to guide safer driving. The report says hard-braking incidents fell by 98% and accidents fell by 70%.
• Use technology to monitor signs of strain: A smartphone app analyzes changes in fingertip color to estimate autonomic nervous system activity and assess fatigue.
• Support gut health as part of managing stress: Under Dr. Kobayashi’s guidance, two women tried a mix of fermented foods, including yogurt and kimchi. The report also mentions extra-virgin olive oil to help with bowel regularity.
• Pay attention to sleep and daily energy: One participant reported shallow sleep and waking tired before making changes. Later, she said she felt clearer and more energetic in the morning. The segment presents this as her personal experience, not a guaranteed result.
• Notice and communicate fatigue: The report emphasizes that objective measurements, alongside how someone feels, may help people recognize tiredness and respond appropriately.

Presenters and sources

• A fifth-grade student whose independent research on fatigue was recognized by the Japanese Society for Fatigue Science
• Professor Watanabe, fatigue researcher
• Dr. Kobayashi, who guided the lifestyle changes
• Researchers and specialists associated with the Japanese Society for Fatigue Science and a university in Japan
• A transportation company’s drivers and staff
• Two women participating in the fatigue-recovery effort
• Nippon Television News Japan, the report’s producer