Japanese walking: interval walking and your VO2max

"Japanese walking" has spread across social media as a low-tech alternative to the 10,000-step goal: no gym, no running, just walking that changes pace every three minutes. It appeals because it promises more benefit from the same walk, and unlike many viral routines, it comes from actual randomised trials. Here is what they found, and what they did not.

Where it comes from

The method is interval walking training (IWT), developed by Hiroshi Nose, Shizue Masuki and colleagues at Shinshu University in Matsumoto. They wanted a programme that middle-aged and older people could do on their own, without a gym or a coach, that would still be intense enough to raise fitness. The answer was simple: alternate 3 minutes of fast walking (above about 70% of your peak aerobic capacity for walking) with 3 minutes of slow walking (about 40%), for at least five rounds, on four or more days a week.

What the trials found

Nemoto et al., 2007 — older adults in Japan

In this trial, 246 people with an average age of 63 were randomly assigned to no training, moderate continuous walking (about 50% of peak capacity, with a target of 8,000 or more steps a day) or interval walking. After five months, the interval group had:

• 8% higher peak aerobic capacity on a bike and 9% higher for walking
• 13% stronger knee extension and 17% stronger knee flexion
• a larger fall in resting systolic blood pressure

All of these gains were significantly larger than in the continuous walking group.

Karstoft et al., 2013 — type 2 diabetes in Denmark

Danish researchers compared four months of interval walking with continuous walking matched for energy expenditure and mean intensity in people with type 2 diabetes. VO2max rose by about 16% in the interval group and did not change in the continuous group. Only the interval walkers lost body fat and visceral fat, and their continuous glucose monitor readings improved. The groups were small (12 people in each walking group), so the effect sizes are less certain than the direction. See VO2max, diabetes and insulin sensitivity for the wider evidence.

The pattern fits what we know from running and cycling: for the same total work, intensity is the stronger stimulus for VO2max (see HIIT vs steady cardio). Interval walking is a gentle version of the same idea.

What the evidence does not show

• No longevity trial. Higher fitness is strongly linked to a longer life (see VO2max and longevity), but those studies are observational, and no study links interval walking directly to living longer.
• Adherence was mixed. In the 2007 trial, only about half of the interval walkers (42 of 87) met their training targets. A 2024 review by the same research groups notes that short-term adherence is high but long-term adherence remains a challenge, especially in people with chronic disease or obesity.
• Small and specific samples. Most data come from older Japanese adults and small Danish groups with diabetes. Young, already fit people may need harder work to improve.

How it compares

Walking type	Typical effort	Main strength	Main limit
Easy steady walking	Can sing	Easy to do daily, builds a base	Small VO2max stimulus once you are used to it
Brisk steady walking	Can talk in sentences	Moderate intensity, low injury risk	Gains level off
Interval (Japanese) walking	Short phrases only in brisk phases	Larger gains in fitness and thigh strength	Harder to stick with
Uphill or rucking	Varies with load and slope	Raises intensity without running	More strain on joints and back

A 30-minute Japanese walking session

1. Warm up: walk easily for a few minutes, which can count as your first easy phase.
2. Brisk phase, 3 minutes: walk as fast as you can while staying in control, at or above about 70% of your peak aerobic capacity. Breathing should be deep and you should manage only short phrases. On a 0–10 effort scale this is about 6–7.
3. Easy phase, 3 minutes: slow right down, about 40% of peak capacity, at a pace where you could chat easily.
4. Repeat five times, for 30 minutes in total.
5. Frequency: aim for four or more days a week, as in the trials.

If you use a watch, heart rate in the brisk phases will often sit in the upper part of zone 2 or above. Make it harder over time by walking faster, adding a slope, or adding a sixth round. Fitter walkers can progress to running intervals such as the Norwegian 4×4 or explore running.

Check your starting point with the VO2max calculator or the fitness age calculator, then retest after 8–12 weeks. For why fitness matters more as you get older, see VO2max and ageing.

Safety: interval walking is moderate exercise, but if you have heart disease, uncontrolled blood pressure, diabetes treated with insulin, or joint problems, check with your doctor before starting, and stop if you feel chest pain, dizziness or unusual breathlessness.

Sources

• Nemoto K, et al. Effects of high-intensity interval walking training on physical fitness and blood pressure in middle-aged and older people. Mayo Clin Proc, 2007.
• Karstoft K, et al. The effects of free-living interval-walking training on glycemic control, body composition, and physical fitness in type 2 diabetic patients: a randomized, controlled trial. Diabetes Care, 2013.
• Karstoft K, et al. Health benefits of interval walking training. Appl Physiol Nutr Metab, 2024.
• Masuki S, et al. Interval walking training can increase physical fitness in middle-aged and older people. Exerc Sport Sci Rev, 2017.