Interval Walking Training: Japan’s Simple Fitness Secret

Exercise ranks number 12 on Michael Greger MD’s Daily Dozen checklist – last but certainly not least, backed by overwhelming evidence for its health benefits. Daily movement is one of the few lifestyle habits shared by every Blue Zone population on earth. And here’s the good news: it doesn’t require a gym, expensive equipment, a personal trainer, or hours of your time. Enter interval walking – also called Interval Walking Training (IWT) or “Japanese Walking.” This simple technique alternates brisk and relaxed walking, and to scientists’ surprise, it unlocks significant fitness and health gains in as little as 30 minutes a day.

What is interval walking?

Interval walking training is powerful yet incredibly simple to learn and do:

• Walk at a fast pace for 3 minutes, then recover by walking at a relaxed pace for 3 minutes
• Repeat that cycle — 3 minutes fast, 3 minutes easy — for a total of 5 rounds, about 30 minutes total

If you don’t want to constantly check your watch, search your app store for “interval timer” and you’ll find plenty of free options to automate the 3-on, 3-off cycle for you.

The science: what a 5-month Japanese study found

Researchers at Shinshu University School of Medicine enrolled 246 healthy adults aged 44–78 in a randomized 5-month trial. Participants were divided into three groups: no training, continuous moderate walking (50% aerobic capacity, 8,000+ steps), and high-intensity interval walking (alternating at ≥70% aerobic capacity with recovery periods).

The interval walkers outperformed both other groups across every measure:

• Leg and thigh strength: knee extension improved 13%, flexion 17%
• Cardiovascular fitness: peak aerobic capacity increased 8–9%
• Blood pressure: resting systolic blood pressure dropped significantly
• Time investment: all of these gains came in less total walking time than the steady-walking group

The researchers concluded that interval walking may protect against the age-related declines in muscle strength, aerobic capacity, and blood pressure that drive so much chronic illness.

Why interval walking matters for long-term health

As Michael Greger MD has highlighted, exercise boosts immunity (children running just 6 minutes showed 50% more immune cells), protects against cognitive decline, and improves mood, sleep, and hypertension. Combined with a whole-food, plant-based diet, daily movement is among the most powerful forms of preventive medicine available:

“Exercising for 20 minutes may add an hour to your life. So, for all those who say they don’t have time to work out, exercising gives us a 3-to-1 return on investment!” — Michael Greger MD, founder of NutritionFacts.org, author of How Not to Die, How Not to Diet, and How Not to Age

How to start this weekend

Here’s a practical checklist to get your first IWT session done:

• Shoes: pick supportive walking shoes you’re comfortable in
• Hydration: bring a water bottle — hydration is its own Daily Dozen checkbox
• Pace check: during the brisk intervals your heart rate will rise, but you should still be able to hold a conversation. If you can’t, slow down slightly
• Timer: use a free interval timer app to automate your 3-minute cycles
• Start small: 2–3 cycles is plenty if it’s been a while. Work up to 5 cycles (30 minutes) for the full study-backed benefits

Make it enjoyable with music or a walking buddy. And if you live near forest trails, do your interval walking there — research on “forest bathing” suggests that exercising among trees adds a meaningful immune-boosting effect on top of the exercise itself.

Frequently Asked Questions About Interval Walking

What is interval walking training? Interval walking training (IWT) is a walking method that alternates between brisk and relaxed walking in timed cycles — typically 3 minutes fast followed by 3 minutes easy, repeated 5 times for a 30-minute session. Developed and studied in Japan, it is sometimes called Japanese Walking.

Is interval walking better than regular walking? According to a 5-month randomized study at Shinshu University, yes — interval walkers outperformed steady-pace walkers across every measured outcome, including leg strength, cardiovascular fitness, and blood pressure, in less total walking time.

How fast should you walk during interval walking? During the brisk intervals, aim for roughly 70% of your aerobic capacity — a pace that raises your heart rate noticeably but still allows you to hold a conversation. If you cannot speak comfortably, slow down slightly. The recovery intervals should feel genuinely easy.

How long should an interval walking session be? A full session is approximately 30 minutes — five cycles of 3 minutes brisk walking followed by 3 minutes easy walking. Beginners can start with 2–3 cycles and build up gradually.

Does interval walking help with blood pressure? Yes. The Shinshu University study found that participants doing interval walking training saw significant reductions in resting systolic blood pressure over 5 months, outperforming both the steady-walking group and the no-exercise group.

Can interval walking build muscle? The same study found that interval walkers improved knee extension strength by 13% and knee flexion by 17% over 5 months — meaningful muscle gains from walking alone, with no gym required.

Do I need any equipment for interval walking? No. All you need is supportive walking shoes, water, and a free interval timer app on your phone to automate the 3-minute cycles. No gym membership, weights, or special gear required.