Japanese walking research: every study, with sources
This page lists the studies behind Japanese walking (interval walking training, IWT) and the wider walking research that Ayumi's pages cite. For each one you can see who took part, what they did and what they found, with a link to the PubMed record. Studies of interval walking itself come first; studies of walking in general come second, and the page says which is which.
- The method in the studies: 3 minutes of fast walking, 3 minutes of slow walking, repeated 5 or more times a day, at least 4 days a week, for 5 months.
- The best-known trial (Nemoto 2007): 246 adults, average age 63, randomized. In the interval group, peak aerobic capacity for walking rose 9%, knee extension strength 13% and knee flexion strength 17%.
- Not shown: interval walking itself did not significantly improve sleep quality in older adults with poor sleep (Kamiya 2024).
Studies of interval walking itself
Nemoto et al., Mayo Clinic Proceedings, 2007
Effects of high-intensity interval walking training on physical fitness and blood pressure in middle-aged and older people · PMID 17605959 · DOI
Who took part and what they did. Randomized trial of 60 men and 186 women, average age 63, split into no walking training, steady moderate walking (8,000 or more steps a day, 4 or more days a week) or interval walking (5 or more sets a day of 3 minutes at 40% and 3 minutes above 70% of peak aerobic capacity, 4 or more days a week). 5 months.
What they found. Interval group: peak aerobic capacity for walking +9% (for cycling +8%), knee extension strength +13%, knee flexion strength +17%. Resting systolic blood pressure fell more in the interval group than in the steady walking group (P = .01); no mmHg figure is quoted here.
Masuki et al., Mayo Clinic Proceedings, 2019
High-intensity walking time is a key determinant to increase physical fitness and improve health outcomes after interval walking training in middle-aged and older people · PMID 31477320 · DOI
Who took part and what they did. 679 men and women, average age 65, did 5 months of interval walking (5 or more sets a day of 3 minutes fast at 70% or more and 3 minutes slow at 40% of estimated peak aerobic capacity, 4 or more days a week). No control group.
What they found. Estimated peak aerobic capacity rose 14% and the lifestyle-related disease score fell 17% on average. Gains grew with weekly fast-walking time up to about 50 minutes, then levelled off; slow or total walking time did not predict gains.
Kamiya et al., Sleep Medicine, 2024
Effects of intensity, frequency, and time window of exercise on sleep quality among community-dwelling adults aged 65-86 years · PMID 38692218 · DOI
Who took part and what they did. Adults aged 65 or older with poor sleep (Pittsburgh Sleep Quality Index above 5): 63 did 5 months of interval walking, 65 formed a comparison group.
What they found. The change in sleep quality did not differ significantly between the two groups, in men or in women. Within the walking group some people improved, depending on when and how often they walked (for example men who walked 5 or more days a week). The authors concluded that interval walking does not significantly improve sleep quality on its own.
Studies of walking and exercise in general
These studies looked at walking or exercise in general, not at the 3-minute interval method. They give context; they do not prove that Japanese walking does the same.
Lee et al., Cochrane Database of Systematic Reviews, 2021
Walking for hypertension · PMID 33630309 · DOI
Who took part and what they did. Cochrane review of 73 randomized trials: walking (mostly moderate pace, on average about 153 minutes a week for about 15 weeks) compared with no walking. Walking in general, not interval walking.
What they found. Systolic blood pressure about 4.1 mmHg lower (95% CI 3.0 to 5.2 lower, moderate certainty); diastolic about 1.8 mmHg lower (95% CI 1.1 to 2.5 lower, low certainty).
Pearce et al., JAMA Psychiatry, 2022
Association between physical activity and risk of depression: a systematic review and meta-analysis · PMID 35416941 · DOI
Who took part and what they did. Systematic review and meta-analysis of 15 prospective cohort studies with 191,130 people. Observational: it shows an association, not cause and effect.
What they found. More physical activity went with a lower risk of depression. The steepest gain came at low amounts: about half of the activity equal to 2.5 hours of brisk walking a week already went with much of the lower risk.
Xu et al., JMIR Public Health and Surveillance, 2024
The effect of walking on depressive and anxiety symptoms: systematic review and meta-analysis · PMID 39045858 · DOI
Who took part and what they did. Systematic review and meta-analysis of 75 randomized trials with 8,636 people: walking compared with inactive comparison groups.
What they found. Walking reduced depressive symptoms (standardized mean difference −0.59) and anxiety symptoms (−0.45). The effect showed up indoors and outdoors and across frequency and duration subgroups.
Noetel et al., BMJ, 2024
Effect of exercise for depression: systematic review and network meta-analysis of randomised controlled trials · PMID 38355154 · DOI
Who took part and what they did. Systematic review and network meta-analysis of 218 randomized trials of exercise for depression.
What they found. Walking or jogging gave a moderate reduction in depression (Hedges' g −0.62), larger at higher intensity.
Kredlow et al., Journal of Behavioral Medicine, 2015
The effects of physical activity on sleep: a meta-analytic review · PMID 25596964 · DOI
Who took part and what they did. Meta-analysis of 66 studies of physical activity and sleep.
What they found. Regular exercise brought small gains in total sleep time and sleep efficiency, small-to-moderate gains in the time taken to fall asleep and a moderate gain in sleep quality. Age, sex, exercise type, time of day and duration changed the effect; intensity did not.
Bratman et al., Proceedings of the National Academy of Sciences, 2015
Nature experience reduces rumination and subgenual prefrontal cortex activation · PMID 26124129 · DOI
Who took part and what they did. Small experiment: a 90-minute walk in nature compared with a 90-minute walk in a city.
What they found. The nature walk reduced rumination (repetitive negative thinking) and activity in a brain region linked to it; the city walk did not.
What the research does not show
- Interval walking itself has not been shown to improve sleep quality (Kamiya 2024). Where Ayumi's pages mention sleep or mood, the evidence is about walking in general and is labelled that way.
- Masuki 2019 had no control group, so it supports the earlier randomized trial rather than proving it.
- Pearce 2022 is observational: people who move more also differ in other ways.
- Not everyone reaches the targets. In Nemoto 2007, 11 of 19 men and 31 of 68 women in the interval group did.
- We quote no weight-loss figure because we have not verified one, and Ayumi makes no weight-loss promise.
- All results are group averages; your own result will differ.
How we use sources
Every number on Ayumi's pages comes from this list. Before a study is added we read its published abstract on PubMed or Europe PMC and check who took part, how long it lasted, what was compared and what was measured. We write the figure the way the paper does and state the conditions next to it.
We keep interval walking studies apart from studies of walking in general, and we say when a result is observational or has no control group. We do not use star ratings, testimonials or before-and-after stories as evidence.
When we verify new research we add it here and update the date above. If you spot a mistake, write to erengn@gmail.com and we will correct it.
This page is general information, not medical advice. Ayumi is a walking app, not a medical device. If you have a heart condition, high blood pressure or other health concerns, talk to your doctor before starting a new exercise routine.
Japanese walking research: common questions
Is there research behind Japanese walking?
Yes. Japanese walking is interval walking training, developed and studied at Shinshu University in Japan. The best-known trial is a randomized study of 246 adults with an average age of 63 over 5 months: the interval walking group raised peak aerobic capacity for walking by 9% and knee strength by 13 to 17% (Nemoto et al., Mayo Clinic Proceedings, 2007, PMID 17605959).
How much of the walking needs to be fast?
In a study of 679 people, fitness gains grew with weekly fast-walking time up to about 50 minutes and then levelled off, while slow or total walking time did not predict gains (Masuki et al., Mayo Clinic Proceedings, 2019, PMID 31477320). The study had no control group.
Does Japanese walking improve sleep or mood?
Interval walking itself did not significantly improve sleep quality in adults aged 65 and over with poor sleep (PMID 38692218). Walking in general reduces symptoms of depression and anxiety in reviews of randomized trials (PMID 39045858 and PMID 38355154), but those studies were not about the 3-minute interval method.
Does walking lower blood pressure?
A Cochrane review of 73 randomized trials found that walking lowered systolic blood pressure by about 4.1 mmHg and diastolic by about 1.8 mmHg compared with no walking (PMID 33630309). It covers walking in general; in the interval walking trial of 246 adults, systolic pressure fell more with interval walking than with steady walking (PMID 17605959).
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