Usual walking speed is the most frequent walking speed in daily life, and there are many academic papers elucidating a close relationship with health after the age of 45. Hereafter, it is abbreviated as Usual Speed.
１．Usual speed at age 45 & midlife aging, lifelong brain health
Association of Neurocognitive and Physical Function with Gait Speed in Midlife
A 50-year cohort study of 904 New Zealand individuals associated walking speed at age 45 with accelerated aging, including decreases in brain volume and cortical thickness.
https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2752818
２．Usual Speed and Successful Aging After Age 55
Physical Activity at Midlife in Relation to Successful Survival in Women at Age 70 Years or Older
A study of 13,535 nurses in the United States found that successful aging after age 70 was associated with walking speed 9 to 15 years earlier.
Successful aging is defined as (1) no serious illness such as cancer, diabetes, or myocardial infarction, (2) no cognitive impairment, (3) no physical disability, and (4) good mental health. defined.
https://doi.org/10.1001/archinternmed.2009.503
３．Usual Speed and cardiovascular mortality risk in middle-aged and older adults
A large UK study of 430,727 middle-aged and older adults without cancer or heart disease found that walking speed may be a useful measure of all-cause and cardiovascular mortality risk.
https://academic.oup.com/eurheartj/article/38/43/3232/4090989
４．Usual Speed and mortality in late middle age
In the UK Longevity Study, a follow-up study of 6,266 middle-aged and older adults over 6 years showed that walking speed was associated with mortality.
https://link.springer.com/article/10.1007/s11357-012-9387-9
５．Usual Speed and telomere length(indicator of cellular youth)
Investigation of a UK biobank cohort reveals causal associations of self-reported walking pace with telomere length
A UK study of 400,000 people (average age 56.5 years) showed a possible causal relationship between faster walking and longer telomeres.
https://www.nature.com/articles/s42003-022-03323-x
６．Usual Speed and stroke
Association Between Walking Pace and Stroke Incidence
In a follow-up study of 363,137 people (aged 37 to 73 years) in the UK over 6 years, walking speed was associated with an increased risk of stroke in those 64 years and older.
https://www.ahajournals.org/doi/10.1161/STROKEAHA.119.028064#:~:text=Slow%20walking%20pace%20was%20associated,1.66%5D%3B%20P%3C0.0001
７．Improved Usual Speed and mortality
Improvement in Usual Gait Speed Predicts Better Survival in Older Adults
A study of 439 people in the United States found that one-year improvements in usual walking speed predicted a significant reduction in mortality and could be a useful “vital sign” for older adults.
https://agsjournals.onlinelibrary.wiley.com/doi/10.1111/j.1532-5415.2007.01413.x
８．Usual Speed and biological age
In an article from the University of Southern California, not an academic study, “In the future, doctors may use walking speed to help determine a person’s biological age,” the researchers said.
https://hscnews.usc.edu/how-fast-you-walk-says-a-lot-about-your-health
９．Usual Speed & the risk of severe COVID-19
Obesity, walking pace and risk of severe COVID-19 and mortality: analysis of UK Biobank
A UK study of 412,596 people reported that, apart from obesity, slow walking speed increased the risk of severe disease.
https://www.nature.com/articles/s41366-021-00771-z#:~:text=shown%20in%20Fig.-,1.,2.42%20(1.53%2C%203.84)
１０．Cadence & pre-frailty, frailty
The following research shows that healthy subjects and pre-frailty/frailty can be distinguished by cadence (number of steps per minute) rather than walking speed.
Wearable Sensors Technology as a Tool for Discriminating Frailty Levels During Instrumented Gait Analysis
In a study of 133 people wearing sensors, the criteria of walking cycle 1.19 seconds, (cadence 101 steps/min) discriminated pre-frailty or frailty from healthy subjects with sufficient sensitivity.
https://www.mdpi.com/2076-3417/10/23/8451/htm
Frailty and Technology: A Systematic Review of Gait Analysis in Those with Frailty
In a study that superimposed multiple academic studies, the indicators for judging healthy subjects and pre-frailty were a decrease in cadence and an increase in stride fluctuation, whereas pre-frailty and frailty showed a narrower usual stride and increased time standing with two legs.
https://pubmed.ncbi.nlm.nih.gov/23949441/
１１．Usual Speed and motor cognitive risk syndrome
Motor Cognitive Risk Syndrome, a hallmark of predementia that combines self-reported dementia symptoms and slow gait, has been shown to predict dementia. (Professor Joe Verghese article)
Walking speed is called a geriatric vital sign that predicts not only dementia but also other geriatric syndromes such as falls, frailty and disability. Although it is not yet clear whether gait or cognition is the cause and the other a consequence, epidemiological studies have observed that regular exercise to improve mobility reduces dementia risk. A speed drop of 0.05 m/s per year is an important signal.
https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2792824
Motoric Cognitive Risk Syndrome: A Risk Factor for Cognitive Impairment and Dementia in Different Populations
Locomotion is a complex movement involving central and peripheral neural control mechanisms. Neighboring brain regions control both locomotion and cognitive functions, particularly the frontal lobe and frontal lobe-related networks. Pilot intervention trials to enhance executive function through either cognitive training or brain stimulation have shown improvements in walking speed.
https://www.e-agmr.org/journal/view.php?doi=10.4235/agmr.20.0001
１２．Usual Speed and brain gray matter
Association between gait, cognition, and gray matter volumes in mild cognitive impairment and healthy controls
A study of gray matter in the brains of 43 individuals with normal cognition and 43 individuals with mild cognitive impairment in Italy found an association between gray matter volume and walking speed.
https://pubmed.ncbi.nlm.nih.gov/31977569/
１３．Usual Speed and mild cognitive impairment, dementia
Walking Speed, Cognitive Function, and Dementia Risk in the English Longitudinal Study of Ageing (usual speed)
A 14-year study of 3,932 people over the age of 60 in the United Kingdom found that those who walked slowly and whose speed decreased significantly over time, were at increased risk of developing dementia, independent of cognitive changes.
https://agsjournals.onlinelibrary.wiley.com/doi/full/10.1111/jgs.15312
The trajectory of gait speed preceding MCI
In a follow-up study of 204 people in the United States for up to 20 years, decline in motor function as measured by walking speed was a leading indicator that accelerated up to 12 years before the onset of mild cognitive impairment (MCI).
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2921227/
Reduced Walking Speed in Subjective and Mild Cognitive Impairment: A Cross-Sectional Study
A Norwegian study of 69 people suggested that usual walking speed declines progressively with early symptoms of cognitive impairment and may be affected at the very early stages of neurodegeneration.
https://journals.lww.com/jgpt/Fulltext/2019/07000/Reduced_Walking_Speed_in_Subjective_and_Mild.29.aspx
１４．Usual Speed and health risks
Prognostic Value of Usual Gait Speed in Well-Functioning Older People—Results from the Health, Aging and Body Composition Study
A 4.9-year follow-up study of 3,047 normally functioning individuals (mean age:74.2 years) in the United States found that a usual walking speed of less than 1 m/s was associated with increased health-related risks including severe lower extremity disability, death and hospitalization.
https://agsjournals.onlinelibrary.wiley.com/doi/10.1111/j.1532-5415.2005.53501.x