Author: Robert Reiman, psychologist
10 000 steps a day sounds like a universally accepted, science-backed goal. But the story behind this number began in marketing. The science tells us a far more gradual story.
In 1965, the Japanese company Yamasa launched a pedometer called manpo-kei, meaning “10 000 steps meter” (Lee et al., 2019). The Japanese character for 10,000, 万, has even been compared to the shape of a walking person. The round, catchy number worked well in marketing – and it stuck.
So the idea took hold that 10 000 steps a day is a scientifically established threshold: more than that is enough, less is too little. But research does not support such a magic threshold. The real question is what the relationship between steps and wellbeing actually looks like and whether average population patterns tell us anything about one individual’s own days.
One number doesn’t describe the shape of the curve
Zhang et al. (2025) studied 820 Chinese university students. Participants wore wrist-based motion sensors and completed the WHO-5, a five-item wellbeing questionnaire. Across individuals, a higher average step count was associated with a higher WHO-5 score, but the relationship was not linear.
The curve rose more steeply at lower step counts and flattened out at around ≈8,650 steps per day. This 8,650 was not a threshold where something suddenly changed, nor a new target to aim for. The study included only university students, and steps and WHO-5 were measured over a single short period – so the result shows an association, not evidence that adding steps caused a change in wellbeing.
The average person doesn’t exist. You are one separate whole person
When studies compare people to one another, they ask, for example, whether people who take more steps tend to score differently on the WHO-5 than those who take fewer steps. This doesn’t yet answer the question of whether the same person feels different on their more active days compared to their less active ones.
“What distinguishes people from each other may not be the same thing that distinguishes your own days from one another.”
The meta-analysis by Bourke et al. (2025), which pooled results from many studies, looked at exactly this second question. A small positive association was found between general physical activity and subjective daily ratings, r ≈ 0.13. In other words, on more active days, ratings tended to be slightly more positive on average, but with many exceptions.
Across the pooled studies, physical activity and wellbeing were measured in various ways, and not all studies used daily step counts or questionnaires comparable to Mentastic’s evening mood check-in. So the small association found by Bourke et al. (2025) cannot be directly compared to findings from Mentastic’s own research. It provides background knowledge about the average association seen across many studies, but does not predict what pattern will appear in any one person’s own days.
There is no magic number
Debunking the 10,000 steps myth does not mean that activity doesn’t matter. Rather, one artificially precise benchmark disappears.
Research does not show a single universal step threshold that divides days into “enough” and “too little.” Associations emerge gradually, average associations can be small, and one person’s own days may differ from the general pattern.
Estonian national physical activity guidelines follow a different logic altogether. The National Institute for Health Development (2025) emphasises regular movement and the duration and intensity of activity — not a specific step count to reach each day:
- Move regularly, ideally at least 30 minutes every day.
- Accumulate 150–300 minutes of moderate-intensity activity per week, or 75–150 minutes of vigorous-intensity activity, or a combination of both.
- Do muscle-strengthening exercises for all major muscle groups on at least two days per week.
- Do balance and stretching exercises on at least three days per week.
So instead of 10 000, another idea might be worth remembering: what matters is not a magic daily number, but the pattern of movement that builds from day to day.
This keeps activity in its rightful place – without one number becoming a universal measuring stick.
nd this is precisely where general knowledge becomes a personal question: on YOUR more active days, did your evening mood tend to be different than on your less active days? Did some pattern repeat or were the days very different from one another?
REFERENCES
Lee, I.-M., Shiroma, E. J., Kamada, M., Bassett, D. R. Jr., Matthews, C. E., & Buring, J. E. (2019). Association of Step Volume and Intensity With All-Cause Mortality in Older Women. JAMA Internal Medicine, 179(8), 1105–1112. DOI: 10.1001/jamainternmed.2019.0899.
Zhang, H., Wang, S., Huang, Y., Xiu, L., & Wang, Y. (2025). Inverted-U association between daily steps and WHO-5 in university students: non-linear modeling and robustness checks. Frontiers in Behavioral Neuroscience, 19, 1693386. DOI: 10.3389/fnbeh.2025.1693386.
Bourke, M., Judge-Mears, B., Guo, B., & Fortnum, K. A meta-analytic review of the within-person association between daily physical activity and sedentary time with subjective wellbeing. Health Psychology Review. DOI: 10.1080/17437199.2025.2590489.
National Institute for Health Development. (2025). Estonian national dietary, physical activity and sleep recommendations: Summary tables. National Institute for Health Development.