Overcoming Inactivity in Older Adults: Impact on Vascular Homeostasis

The American Heart Association (AHA) and American College of Sports Medicine (ASCM) recommend
older adults (50≤ age ≤ 80) perform at least 30 minutes of moderate-intensity aerobic
exercise on most days ( ≥5 days) of the week. This suggestion arises, in part, from data
supporting that regular physical activity reduces the risk of adverse cardiovascular events A
portion of these benefits may be from reductions in the incidence and severity of
cardiovascular risk factors, including diabetes mellitus, obesity, and hypertension.

While this recommendation for physical activity has been in existence for almost 15 years,
the rates of obesity in the United States continue to rise and prevalence of sedentarism
remains at best unchanged. Researchers have been engaged in investigating novel interventions
to designed increase physical activity to reach the recommended activity targets. One
promising intervention involves use of inexpensive, easy to use pedometers that allow
individuals to objectively track the number of steps taken during a set period of time.
Recent data suggest that an average of 10,000 steps/day as measured by a pedometer accurately
estimates the activity levels recommended by the AHA, ASCM, and US government public health
guidelines.

While the benefits of habitual exercise are well-documented, there are no data that
demonstrate current recommendations for moderate physical activity in older adults by the
ASCM, AHA, and US public health guidelines reduce the risk of adverse cardiovascular events.
Interestingly, prior work indicates that pedometer-centered interventions can increase
physical activity, suggesting that this type of intervention could potentially lead to
cardiovascular benefits. Using validated surrogate markers of cardiovascular risk including
brachial artery endothelial function, tonometric measurements of vascular stiffness, and
measurements derived from transthoracic echocardiography, we will determine whether
increasing the physical activity of sedentary adults to an average of 10,000 steps or
more/day translates into improvements in cardiovascular health. This will be determined in
the context of a randomized control trial employing a control group, a study group that uses
a pedometer alone, and an intervention that couples a pedometer with internet-based
motivational messaging software demonstrated in our preliminary data to encourage older
adults to reach and exceed the 10,000 steps/day goal.