Science behind Scores

The Science behind the Activity Score

Physical activity is one of the most important determinants of health, longevity, and quality of life. The Activity Score is built upon a strong foundation of scientific evidence, bringing together the most impactful aspects of daily movement to provide a clear, actionable measure of your physical engagement. By understanding the science that underpins each contributing factor, anyone can see how even modest changes in daily habits have measurable impacts, helping to unlock a healthier, more active life.


1. Steps

What is it?

The total number of steps taken in a day—capturing walking, running, and general ambulation.

Why it matters:

Daily step count is among the simplest and most widely studied measures of physical activity. Even modest increases in step count are associated with substantial reductions in mortality and chronic disease risk.

What the science shows:

  • Each additional 1,000 steps per day reduces your risk of death from any cause by 6–15% (Banach et al., 2023).

  • Averaging 7,000–10,000 steps per day is an evidence-based goal, but significant benefits start as low as 4,000–6,000 steps/day compared to being sedentary (Banach et al., 2023, Hansen et al., 2022; Paluch et al., 2021).

  • People in the highest step-count group have up to a 40–50% lower risk of premature death, cardiovascular disease, diabetes, and certain cancers compared to those with the lowest step counts (Paluch et al., 2022; Del Pozo Cruz et al., 2022; Hall et al., 2020).

2. Active Hours

What is it?

The number of hours in a day during which any movement is detected—from light activity like walking to more intense exercise.

Why it matters:

Distributing activity across more hours each day is uniquely beneficial. Prolonged sedentary periods are linked to higher health risks. Regular movement throughout the day supports healthy metabolism, circulation, mood, and brain function..

What the science shows:

  • People with ≥8 active hours per day have up to a 30% lower risk of developing metabolic syndrome compared to those with <4 hours active (Kim et al., 2013)

  • Each additional hour where movement occurs (even light movement like slow walking, standing, or household chores) lowers odds of abnormal blood sugar by 11–14% (Healy et al., 2007; Smith et al, 2024).

  • Spreading movement throughout the day (versus being active only in one block) is associated with measurable improvements in cognitive performance in older adults (Smagula et al., 2022).

3. Active Calories

What is it?

The total calories burned during periods of movement or structured exercise.

Why it matters:

Active calorie expenditure is a direct proxy for energy output, which underpins weight management and supports metabolic health. Higher activity-related energy expenditure improves cardiovascular fitness and lowers risk of obesity, diabetes, and heart disease.

What the science shows:

  • Each additional 1,000 calories burned per week through physical activity is linked to a 20–30% reduction in risk of cardiovascular disease and premature death (Lee & Paffenbarger, 2000).

  • Every 10 MET-hour per week of physical activity (about 2.5 hours of brisk walking or ~700 kcal for an 80-kg person) is linked to a 13% reduction in type 2 diabetes risk (Aune et al., 2015).

  • A negative or balanced energy equation—burning as many or more calories than consumed—is fundamental for preventing obesity and its associated diseases (Piercy et al., 2018).

4. Intense Activity Duration

What is it?

The cumulative time spent in moderate to vigorous physical activity (MVPA) such as brisk walking, running, cycling, or intense sports—activities that significantly raise your heart rate and breathing.

Why it matters:

Short bursts of higher-intensity activity yield outsized health benefits, improving cardiovascular fitness, muscle strength, and metabolic health more efficiently than lower-intensity activity.

What the science shows:

  • Meeting WHO activity guidelines (150 min/week moderate or 75 min/week vigorous) is linked to a 31% lower risk of all-cause mortality, 33% lower risk of heart disease, and 25–35% lower risk of type 2 diabetes (WHO, 2020; Arem et al., 2015; Kyu et al., 2016; Jeon et al., 2007).

  • Even as little as 10 minutes/day of vigorous activity improves aerobic fitness and lowers all-cause mortality by 6-13% compared to doing none (Saint-Maurice et al., 2022; Swift et al., 2018).

  • Greater amounts—over 300 min/week of moderate activity—provide up to 39% lower risk of all-cause mortality and lead to further gains in cardiorespiratory fitness, blood pressure, and mental health (Arem et al., 2015; Piercy et al., 2018).

5. Extended Inactivity

What is it?

The total amount of time spent in sedentary behavior —sitting, reclining, or being inactive—especially when these periods last longer than 30–60 minutes without a break.

Why it matters:

Prolonged, uninterrupted inactivity is an independent health risk—even if you otherwise exercise. Breaking up sitting time is critical for metabolic health, cardiovascular function, and longevity.

What the science shows:

  • Sitting for more than 8 hours per day is associated with a 20–40% higher risk of all-cause mortality and heart disease, even after accounting for exercise (Ekelund et al., 2016; Biswas et al., 2015).

  • People who spend more time sitting—especially in prolonged, uninterrupted bouts—tend to have larger waist circumference, higher blood pressure, and greater risk of type 2 diabetes, independent of total physical activity levels (Healy et al., 2008; Dunstan et al., 2012).

  • Standing up or walking for 2–3 minutes every 30 minutes can improve blood sugar and insulin levels by ~20–25% and reduce fatigue (Dunstan et al., 2012; Bailey et al., 2019).

6. Floors Climbed

What is it?

The number of floors (or flights of stairs) climbed throughout the day.

Why it matters:

Stair climbing is a vigorous physical activity, requiring greater energy output and muscle engagement than walking on level ground. It is a practical way to improve cardiovascular health, muscular strength, and functional fitness.

What the science shows:

  • Climbing more than 55 flights per week is associated with 29% lower risk of death compared to climbing less than 10 flights per week (Paffenbarger et al., 1993).

  • Stair climbing interventions in inactive adults have been shown to increase cardiorespiratory fitness by 10–16% over 8 weeks (Boreham et al., 2005).

  • Each additional flight of stairs climbed daily is associated with a reduced risk of atherosclerotic cardiovascular disease—including heart attack and stroke (Song et al., 2023).


Conclusion

The Activity Score is grounded in decades of rigorous research, translating complex evidence into meaningful guidance for everyday life. By monitoring key dimensions of movement, the score offers a transparent, science-based roadmap for improvement. Whether optimizing for personal health, designing applications, or guiding organizational wellness, these foundations ensure that every step taken is a step toward better health outcomes.

References

  1. Banach, M., Lewek, J., Surma, S., Penson, P. E., Sahebkar, A., Martin, S. S., Bajraktari, G., Henein, M. Y., Reiner, Ž., Bielecka-Dąbrowa, A., & Bytyçi, I. (2023). The association between daily step count and all-cause and cardiovascular mortality: A meta-analysis. European Journal of Preventive Cardiology, 30(18), 1975–1985. https://doi.org/10.1093/eurjpc/zwad229

  2. Hansen, B. H., Dalene, K. E., Ekelund, U., & Fagerland, M. W. (2022). Step count and all-cause mortality among free-living adults: A systematic review and meta-analysis of prospective cohort studies. The Lancet Public Health, 7(3), e219–e228. https://doi.org/10.1016/S2468-2667(21)00302-9

  3. Paluch, A. E., Gabriel, K. P., Fulton, J. E., Lewis, C. E., Schreiner, P. J., Sternfeld, B., & Sidney, S. (2021). Steps per day and all-cause mortality in middle-aged adults in the Coronary Artery Risk Development in Young Adults study. JAMA Network Open, 4(9), e2124516. https://doi.org/10.1001/jamanetworkopen.2021.24516

  4. Paluch, A. E., Bajpai, S., Bassett, D. R., Carnethon, M. R., Ekelund, U., Evenson, K. R., ... & Fulton, J. E. (2022). Daily steps and all-cause mortality: a meta-analysis of 15 international cohorts. The Lancet Public Health, 7(3), e219–e228. https://doi.org/10.1016/S2468-2667(21)00302-9

  5. Del Pozo Cruz, B., Ahmadi, M. N., Lee, I.-M., & Stamatakis, E. (2022). Prospective associations of daily step counts and intensity with cancer and cardiovascular disease incidence and mortality and all-cause mortality. JAMA Internal Medicine, 182(11), 1139–1148. https://doi.org/10.1001/jamainternmed.2022.4000

  6. Hall, K. S., Hyde, E. T., Bassett, D. R., Carlson, J. A., Carnethon, M. R., Ekelund, U., Kraus, W. E., Matthews, C. E., & McAuley, E. (2020). Systematic review of the prospective association of daily step counts with risk of mortality, cardiovascular disease, and dysglycemia. International Journal of Behavioral Nutrition and Physical Activity, 17, 78. https://doi.org/10.1186/s12966-020-00978-9

  7. Kim, J., Tanabe, K., Yokoyama, N., Zempo, H., & Kuno, S. (2013). Objectively measured light-intensity lifestyle activity and sedentary time are independently associated with metabolic syndrome: A cross-sectional study of Japanese adults. International Journal of Behavioral Nutrition and Physical Activity, 10(1), 30. https://doi.org/10.1186/1479-5868-10-30

  8. Healy, G. N., Dunstan, D. W., Salmon, J., Shaw, J. E., Zimmet, P. Z., & Owen, N. (2007). Objectively measured light-intensity physical activity is independently associated with 2-h plasma glucose. Diabetes Care, 30(6), 1384–1389. https://doi.org/10.2337/dc07-0114

  9. Smith, L., Ekelund, U., & Hamer, M. (2024). Effects of interrupting prolonged sitting with light-intensity physical activity on inflammatory and cardiometabolic risk markers: A randomized controlled trial. Biomolecules, 14(8), 1029. https://doi.org/10.3390/biom14081029

  10. Smagula, S. F., Zhang, G., Gujral, S., Covassin, N., Li, J., Taylor, W. D., Reynolds, C. F., & Krafty, R. T. (2022). Association of 24-Hour Activity Pattern Phenotypes With Depression Symptoms and Cognitive Performance in Aging. JAMA Psychiatry. https://doi.org/10.1001/jamapsychiatry.2022.2573

  11. Lee, I. M., & Paffenbarger, R. S. (2000). Physical activity and coronary heart disease in men: The Harvard Alumni Health Study. Circulation, 102(9), 975–980. https://doi.org/10.1161/01.CIR.102.9.975

  12. Aune, D., Norat, T., Leitzmann, M., Tonstad, S., & Vatten, L. J. (2015). Physical activity and the risk of type 2 diabetes: a systematic review and dose-response meta-analysis. European Journal of Epidemiology, 30(7), 529–542. https://doi.org/10.1007/s10654-015-0056-z

  13. Piercy, K. L., Troiano, R. P., Ballard, R. M., Carlson, S. A., Fulton, J. E., Galuska, D. A., ... & Olson, R. D. (2018). The Physical Activity Guidelines for Americans. JAMA, 320(19), 2020–2028. https://doi.org/10.1001/jama.2018.14854

  14. World Health Organization. (2020). WHO guidelines on physical activity and sedentary behaviour. World Health Organization. https://www.who.int/publications/i/item/9789240015128

  15. Arem, H., Moore, S. C., Patel, A., Hartge, P., Berrington de González, A., Visvanathan, K., ... & Matthews, C. E. (2015). Leisure time physical activity and mortality: a detailed pooled analysis of the dose-response relationship. JAMA Internal Medicine, 175(6), 959–967. https://doi.org/10.1001/jamainternmed.2015.0533

  16. Kyu, H. H., Bachman, V. F., Alexander, L. T., Mumford, J. E., Afshin, A., Estep, K., ... & Forouzanfar, M. H. (2016). Physical activity and risk of breast cancer, colon cancer, diabetes, ischemic heart disease, and ischemic stroke events: systematic review and dose-response meta-analysis for the Global Burden of Disease Study 2013. BMJ, 354, i3857. https://doi.org/10.1136/bmj.i3857

  17. Jeon, C. Y., Lokken, R. P., Hu, F. B., & van Dam, R. M. (2007). Physical activity of moderate intensity and risk of type 2 diabetes: a systematic review. Diabetes Care, 30(3), 744–752. https://doi.org/10.2337/dc06-1842

  18. Saint-Maurice, P. F., Graubard, B. I., Troiano, R. P., Carlson, S. A., & Matthews, C. E. (2022). Estimated number of deaths prevented through increased physical activity among US adults. JAMA Internal Medicine, 182(4), 349–352. https://doi.org/10.1001/jamainternmed.2021.7755

  19. Swift, D. L., Johannsen, N. M., Lavie, C. J., Earnest, C. P., & Church, T. S. (2018). The role of exercise and physical activity in weight loss and maintenance. Progress in Cardiovascular Diseases, 61(2), 206–213. https://doi.org/10.1016/j.pcad.2018.07.014

  20. Ekelund, U., Steene-Johannessen, J., Brown, W. J., Fagerland, M. W., Owen, N., Powell, K. E., ... & Lee, I. M. (2016). Does physical activity attenuate, or even eliminate, the detrimental association of sitting time with mortality? A harmonised meta-analysis of data from more than 1 million men and women. The Lancet, 388(10051), 1302–1310. https://doi.org/10.1016/S0140-6736(16)30370-1

  21. Biswas, A., Oh, P. I., Faulkner, G. E., Bajaj, R. R., Silver, M. A., Mitchell, M. S., & Alter, D. A. (2015). Sedentary time and its association with risk for disease incidence, mortality, and hospitalization in adults: A systematic review and meta-analysis. Annals of Internal Medicine, 162(2), 123–132. https://doi.org/10.7326/M14-1651

  22. Healy, G. N., Dunstan, D. W., Salmon, J., Cerin, E., Shaw, J. E., Zimmet, P. Z., & Owen, N. (2008). Breaks in sedentary time: beneficial associations with metabolic risk. Diabetes Care, 31(4), 661–666. https://doi.org/10.2337/dc07-2046

  23. Dunstan, D. W., Kingwell, B. A., Larsen, R., Healy, G. N., Cerin, E., Hamilton, M. T., ... & Owen, N. (2012). Breaking up prolonged sitting reduces postprandial glucose and insulin responses. Diabetes Care, 35(5), 976–983. https://doi.org/10.2337/dc11-1931

  24. Bailey, D. P., Locke, C. D., & Batterham, A. M. (2019). Breaking up prolonged sitting with light-intensity walking improves postprandial glycemia, but breaking sitting with standing does not. Journal of Science and Medicine in Sport, 22(3), 349–354. https://doi.org/10.1016/j.jsams.2018.08.005

  25. Paffenbarger, R. S., Hyde, R. T., Wing, A. L., & Hsieh, C. C. (1993). Physical activity, all-cause mortality, and longevity of college alumni. New England Journal of Medicine, 328(8), 538–545. https://doi.org/10.1056/NEJM199302253280803

  26. Boreham, C. A. G., Wallace, W. F. M., & Nevill, A. (2005). Training effects of accumulated daily stair-climbing exercise in previously sedentary young women. British Journal of Sports Medicine, 39(9), 590–593. https://doi.org/10.1136/bjsm.2002.001131

  27. Song, Z., Wan, L., Wang, W., Li, Y., Zhao, Y., Zhuang, Z., Dong, X., Xiao, W., Huang, N., Xu, M., Clarke, R., Qi, L., & Huang, T. (2023). Daily stair climbing, disease susceptibility, and risk of atherosclerotic cardiovascular disease: A prospective cohort study. Atherosclerosis, 376, 117300. https://doi.org/10.1016/j.atherosclerosis.2023.117300

  28. Centers for Disease Control and Prevention. (2023). Physical Activity Boosts Brain Health. https://www.cdc.gov/physical-activity/features/boost-brain-health.html

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