Every minute of activity may benefit heart health for mobility-limited older adults

For older adults with limited mobility, each minute of physical activity may contribute toward reduced risk of heart attack and death from heart-related problems. This is according to a new study published in the Journal of the American Heart Association.

Even low-intensity activity, such as slow walking, may have heart benefits for older adults with limited mobility.

The research team at the University of Florida Institute on Aging in Gainesville, says that even engaging in low-intensity activity may pose heart benefits for seniors with mobility problems.

The potential heart benefits of exercise have been well documented.

 We have previously reported that physical activity may reduce the risk of irregular heartbeat in older women, while another study found an hour of exercise a day could halve the risk of heart failure.

The Physical Activity Guidelines for Americans recommend that adults aged 64 and older should engage in at least 150 minutes of moderate-intensity or 75 minutes of vigorous-intensity aerobic exercise each week.

However, in this case the researchers say that for seniors with limited mobility, fulfilling these recommendations may be challenging. As such, the research team set out to determine whether lower levels of activity may still have heart benefits for this population.

Slow walking, light housework linked to higher levels of 'good' cholesterol

Using accelerometers, the researchers measured the physical activity levels of 1,170 people aged 74-84 who were a part of the Lifestyles Interventions and Independence for Elders Study. All participants had mobility problems but were able to walk 400 meters.

An accelerometer reading of 99 counts a minute or less was considered sedentary behavior, while a reading of 100-499 counts a minute indicated slow walking or light housekeeping, and 500 counts a minute or more indicated moderate walking or activities of similar intensity.

The researchers calculated the participants' predicted 10-year risk of heart attack or heart-related death using a number of factors, including age, blood pressure and cholesterol levels.

The findings revealed that for every 25-30 minutes a participant spent sedentary each day, their predicted risk of heart attack or coronary death increased by 1%.

However, among participants with no history of heart disease, accelerometer readings in the range of 100-499 counts a minute was associated with higher levels of high-density lipoprotein (HDL) cholesterol, referred to as "good" cholesterol. 

This cholesterol helps remove low-density lipoprotein (LDL), or "bad" cholesterol, from the arteries, reducing the risk of heart problems.

On average, accelerometer readings among participants only reached 500 counts a minute or more for an hour or less each day.

These findings, the researchers say, indicate that reducing the time spent sedentary may have heart benefits for older adults with limited mobility. 

"In the past, much of the emphasis was placed on engaging in structured physical exercise. It is becoming increasingly evident, however, that encouraging individuals to just reduce the amount of time they spend being sedentary may have important cardiovascular benefits."

The research team notes that their findings do not indicate that one period of exercise will counteract the health risks associated with sedentary behavior.

The idea is that, even if you exercise for an hour in the morning, if you go and sit for 8 hours the rest of the day you may have health risks that are independent of the fact you exercised. This stresses the need for regular intervals of low-level movement and to avoid sitting for excessive stretches of time.

References:

1.  Association of objectively measured physical activity with cardiovascular risk in mobility-limited older adults, Thomas W. Buford, et al., Journal of the American Heart Association, doi: 10.1161/JAHA.114.001288, published online 18 February 2015.
2.  American Heart Association news release, accessed 17 February 2015 via AlphaGalileo.