Exercise as it relates to Disease/Running- the key to Longevity?

The following is an analysis of the article "Leisure-time running reduces all-cause and cardiovascular mortality risk ."



What is the background?
We know that regular physical activity both prevents chronic disease and reduces our risk of cardiovascular disease (CVD). But what type of physical activity should we be doing, and how long should we be doing it for?

In Australia, running as a leisure activity has doubled in it’s popularity in the past 10 years. Recently, there has been a rise in research regarding the health benefits of running in comparison to other physical activity. So what are the benefits associated with being a runner?

A study in the Journal of the American College of Cardiology titled “Leisure Time Running Reduces All-Cause and Cardiovascular Mortality Risk” examined the dose-response associations of running and the risk of all-cause or CVD mortality in 55,137 participants. In addition to the dose-response relations, the research also tested whether there were reduced or increased health benefits for those who partake in higher amounts of running, the effects of moderate vs. vigorous intensity physical activity, and whether the patterns of change in running behaviours have an impact on mortality.

Where is this research from?
This research was published in the United States of America in the Journal of The American College of Cardiology. The researchers, are well-published in the fields of Cardiology, Epidemiology and Public Health.

The data for this study was extracted from the Aerobics Centre Longitudinal Study, with the participants participating in medical examinations in Dallas, Texas. The results of the study are most relevant to those living in southern USA, however it could also be relevant to other Western nations including Australia.

What kind of research was this?
This research was a prospective, observational, cohort study. A group of 55,127 adults aged 18 to 100 years were followed over 15 years to observe what happened to them. Cohort studies generally provide strong information in regards to the cause and risk of developing a disease, however they are observational by nature which limits clinician control. It can be difficult for clinicians to determine which risk factors the population were exposed to, or if they altered their intervening behaviours during the study.

What did the research involve?
The 55,137 adults involved in this study were either self-referred, or referred by their employers or physicians. The benefits of running were then measured through the participants mortality rates and causes over a 15 year period .The participants were a homogenous group of white American adults of middle to upper socio-economic status. Participants who had previously reported having myocardial infarction, stroke, or cancer were excluded from the study to reduce confounding variables. All data analyses were adjusted for "other physical activity", the participants smoking status, BMI, and medical conditions.

The participants running activity was assessed via self-report through a questionnaire which was focused around the distance, duration, frequency, and speed of the running. Participants were defined as “runners” if they reported answers for all 4 detailed questions, and “non-runners” if they did not report any running questions. Changes in running behaviour were broken into 4 categories; “remained non-runners”, “became non-runners”, “became runners”, and finally, “remained runners” if all running questions were answered at both examinations.

Despite data adjustments, confounding variables were still present throughout this study:
 * Being a homogenous rather than heterogenous group, we don’t know the implications of running on the overall population
 * The referral process lends itself to participants who are active in regards to their health, and who are of higher socio-economic status
 * Self-report can be an inaccurate means of collecting data, resulting in measurement bias through the participants inability to accurately re-call past events
 * Participants were not required to report their dietary information, drinking, or recreational drug use, which could potentially impact their mortality rates
 * "Other physical activity" was not specified

What were the basic results?
The results could be over-stated given the observational nature of the study. Despite this, basic results showed that when compared to "non-runners", "runners" had 30% and 45% lower adjusted risks of all-cause and CVD mortality, and a 3-year life expectancy benefit. Not only are "runners" expected to live longer, “runners” are more likely to be younger and leaner, and engage in healthy choices such as not smoking and other physical activity. In addition to this, running at lower doses or slower speeds is still associated with significant mortality benefits when looking at the dose-response relation, and persistent "runners" experienced the most significant mortality reduction.

'''Table 1. Comparison of the risk of All-cause and CVD Mortality by change in running behaviours'''

What conclusions can we make?
The study concludes that running could reduce all-cause and CVD mortality, however a larger, more heterogenous, blinded study is required for a definitive outcome on the long-term benefits of running.

Overall, this study suggests that the mortality benefits are similar across those who run a lot, and those who run a little. The researchers asserted that risk of preventable mortality could be decreased from just 5 minutes (or more) of running per day. The researchers believe that persistent runners (those who run consistently over a period of 5.9 years or more) can experience the greatest decrease in their risk of all-cause and CVD mortality.

Practical advice
To potentially decrease your client's risk of all-cause and CVD mortality, you could encourage them to participate in 5 or more minutes of running per day. Once client consent has been achieved, have them complete the Adult Pre-Exercise Screening Tool to determine if any risk factors or comorbidities exist. Once given the all clear, you could encourage your client to make these short bursts of running every day a habit to potentially decrease their risk of mortality from preventable disease.