Live Longer, Walk Faster : Dean's Corne
(Studenski, S. et al. JAMA 2011;305:50-58).
Staying active, along with a balanced health diet, is probably the best way to age gracefully. An elegantly simple study was just published in the Journal of the American Medical Association that clearly demonstrates the relationship between longevity and walking speed. Researchers studied close to 35,000 people aged 65 years or above (a mean of 74 years) with data taken from six to 21 years.
I love studies such as this - ask a simple question, propose a clear experimental design, and analyze the data carefully, including a statistical analysis. They did not prove that if you walk faster, you can live longer. Instead, they demonstrate that walking speed can be an accurate predictor of longevity, useful for informing physicians about how best to treat their patients. For example, if a patient is predicted to live well more than a decade, it makes sense to consider long term preventative strategies.
According to the paper:
How might gait speed be used clinically? First, gait speed might help identify older adults with a high probability of living for 5 or 10 more years, who may be appropriate targets for preventive interventions that require years for benefit. Second, gait speed might be used to identify older adults with increased risk of early mortality, perhaps those with gait speeds slower than 0.6 m/s. In these patients, further examination is targeted at potentially modifiable risks to health and survival. A recommended evaluation and management of slow walking includes cardiopulmonary, neurological and musculoskeletal systems.6,18 Third, gait speed might promote communication. Primary clinicians might characterize an older adult as likely to be in poor health and function because the gait speed is 0.5 m/s. In research manuscripts, baseline gait speed might help to characterize the overall health of older research participants. Fourth, gait speed might be monitored over time, with a decline indicating a new health problem that requires evaluation. Fifth, gait speed might be used to stratify risks from surgery or chemotherapy. Finally, medical and behavioral interventions might be assessed for their effect on gait speed in clinical trials. Such true experiments could then evaluate causal pathways to determine whether interventions that improve gait speed lead to improvements in function, health, and longevity.
The data provided herein are intended to aid clinicians, investigators, and health system planners who seek simple indicators of health and survival in older adults. Gait speed has potential to be implemented in practice, using a stop watch and a 4-m course. From a standing start, individuals are instructed to walk at their usual pace, as if they were walking down the street, and given no further encouragement or instructions. The data in this article can be used to help interpret the results. Gait speed may be a simple and accessible indicator of the health of the older person.
This gives us something to think about the next time you decide to take a walk - are you a "shuffler" or do you have to slow yourself down sometimes?
