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Walking Speed: A Powerful Predictor of Functional Health
Len Kravitz, PhD

Within the last 10 years there has been a spike of research studies on the association of walking speed and heightened risk of mortality in older men and women (Franklin et al, 2015). Until recently, researchers had no idea that walking speed may be such a strong vital sign predictor. This new research has impactful training implications for personal trainers working with older populations. Not only do fitness pros want to get clients moving more, but the new research indicates moving briskly equates highly to better health.

Gait Speed: A Clinical Marker of Functional Status in Older Adults
Functional health or functional status can be described as the ability to perform all of one's activities of daily living (ADL). This functional training concept has been emphasized for several years in the fitness field. Activities of daily living include self-care activities, such as bathing, dressing, meal preparation, feeding, personal hygiene, as well as activities of living, including shopping, mobility and using means of public transportation. All ADLs are considered to be basic requirements to living healthy and well. Indeed, personal trainers design program plans for clients to enhance function health, with a goal to help clients optimize their ability to perform ADLs. Verghese, Wang and Holtzer (2011) expound that gait speed is a clinical marker of functional status in older adults that reflects an integration of health, disease, fitness and emotional state. In their review, Middleton, Fritz and Lusardi (2015) add that walking speed has been shown to be associated with a range of outcomes including frailty, functional dependence, mobility disability, cognitive decline, falls, hospitalization, as well as call-cause mortality. Franklin et al. (2015) add that slower walking speeds are observed in cancer conditions and with patients in an inflammatory state (i.e., body not coping with a particular medical condition(s)). Verghese and colleagues note that gait speed is influenced by variables such as fitness level, cognition and mood.

Why Does Gait Speed Predict Survival in Older Men and Women?
Studenski et al. (2011) explain that walking requires sufficient energy to move, control balance and support the body in motion that places demands on multiple systems of the body, including the heart, lungs, nervous system, musculoskeletal system and circulatory system. The authors add that a slowing of a person's gait likely reflects damage to any one of these systems or a combination of them. All of these major bodily systems are highly associated to survival, and thus gait speed is now recognized as a straightforward indicator of a person's vitality. The researchers continue that decreasing gait speeds are likely a result of reduced physical activity and deconditioning, which will have a direct effect on an older person's health and survival.

What is the Best Gait Speed for Survival?
The best gait speed for survival is still being fine-tuned by researchers, as this is a very new indicator of vitality. Studenski et al. (2011) summarize that some researchers identify a gait speed of &Mac179;2.2 miles/hour indicate healthier aging (adults &Mac179;65 yrs) while gait speeds slower than 1.3 miles/hour indicate the likelihood of poor health and functional status. Studenski and colleagues continue that walking speeds about 1.8 miles/hour represent the median for older adults. The researchers add that walking speeds of &Mac179;2.7 miles/hour indicate an “exceptional life expectancy, but additional research will be necessary to determine this relationship.” Franklin et al. (2015) suggest there that an enhanced survival to brisk walking is likely to be brisk walking >3 miles/hour. The researches explain that being able to continuous walk >3 miles/hour corresponds to a metabolic equivalent of >3.3 METs. A MET is the equivalent of 3.5 ml oxygen/per kilogram of body weight per minute. Franklin and colleagues explain that older adults who continuously walk at this pace typically have a >5 METs aerobic fitness capacity level. This fitness level characterizes a portion of the population with reduced mortality (Franklin et al). In addition, for persons with or without coronary heart disease, each 1-MET increase in their aerobic fitness capacity has been shown to be associated with an approximate 15% reduction in all cause and cardiovascular disease mortality (Franklin et al).

How is Gait Speed Measured?
In medical clinics, patients are asked to walk 13 to 20 feet from a standing start and their speed is calculated using a stopwatch. The individuals are told to just walk their usual pace with no further encouragement or instructions being provided. Many fitness pros have access to a treadmill where they can accurately and easily determine a client's average walking pace. With access to a treadmill just give the client the following instruction to assess gait speed: 'set the speed on the treadmill to your normal walking pace' Periodically, re-check your clients normal walking pace to note any changes in pace.

Special Implication Messages to Personal Trainers
Clearly, a sedentary lifestyle has been shown to be associated with an increased risk of factors associated with coronary heart disease (Franklin et al., 2015). Research presented in this column suggests that with older men and women clients (&Mac179; 65 yrs), for optimal vitality, a campaign to move more 'with a brisk pace' is associated with enhanced functional health. In the January 2018 Research Column of IFJ we summarized new research suggesting that in an effort to combat the deleterious effects of a sedentary lifestyle, for every 30 minutes of waking behavior adults are encouraged to get 3 minutes of movement. In Table I have created 6 new interval walking workouts to share with your adult male and female clients to do for every 30 minutes of waking behavior. The intensity message is for these clients to move with a brisk walk that feels somewhat hard, relative to their health status. The recovery speed should feel like a light intensity. Take advantage of the numerous intervals apps freely available on smart phones or perhaps provide a pedometer to clients to track walking and movement activities.

As clients become consistently active, some may want to start a walking program. Franklin et al. (2015) summarize research that shows older persons who walked 15 minutes a day (90 minutes a week) over a period of 8 years had a 14% reduction in death rates as compared to their inactive counterparts. Encourage clients to walk continuously, accumulating 30 minutes of somewhat hard walking minutes (i.e., two 15 minute walks or three 10 minute walks during the day) on most days of the week (Franklin et al.). Research shows this will impart even greater improvements in cardiovascular health and well being (Franklin et al).
Final Thoughts
Fitness pros now have a new, genuine, easy-to-use assessment for functional health for older clients. And the major new message to clients is try to make their daily movement brisk. When it comes to their health vital signs, encourage clients to acclimate themselves to walk with an energetic step to their pace.

@bio:Len Kravitz, PhD, CSCS, is the program coordinator of exercise science at the University of New Mexico, where he received the Outstanding Teacher of the Year and Presidential Award of Distinction. In addition to being a 2016 inductee into the National Fitness Hall of Fame, Len was awarded the 2016 CanFitPro Specialty Presenter Award.

Franklin, B.F., Brinks, J., Sacks, R. et al. (2015). Reduced walking speed and distance as harbingers of the approaching grim reaper. American Journal of Cardiology online, 116, 313-317.
Middleton, A., Fritz, S.L., Lusardi, M. (2015). Walking speed: The functional vital sign. Journal of Aging and Physical Activity, 23(2), 314-322.
Studenski, S., Perera, S., Patel, K. (2011). Gait speed and survival in older adults, Journal of the American Medical Association, 305(1), 50-58.
Verghese, J., Wang, C., and Holtzer, R. (2011). Relationship of clinic based gait speed measurement to limitations in community based activities in older adults, Archives of Physical Medicine and Rehabilitation, 92(5), 844-846