Movement as Medicine for Older Adults
Image obtained from Public Domain Vectors
I left a houseplant by the window. After a few weeks I could tell where most of the sunlight was shining; the plant bent and contorted itself until it had positioned most of its leaves in that spot. Movement is necessary to obtain things required for survival, whether you are a houseplant reaching for sunlight, a bacterium moving towards chemicals, a koala moving to eucalyptus, or a human moving to do just about anything.
Humans were built to move. We evolved as marathon hunter gatherers, and while moving on two legs decreased the speed at which we could travel, it increased the distance we could cover through improved stamina. While the term ‘evolved’ makes this sound like something of the past, anatomically and physiologically, we highly resemble the marathon hunter gatherer profile. Yet, our increasingly sedentary lifestyles that generally require us to sit at a desk most of the day does not reflect this ‘built to move’ reality. This can have important consequences as a lack of movement can be at the root of many diseases, accelerating their negative effects as one ages.
Older adults tend to be at the highest risk of poor health due to the natural aging process. Some of the more devastating outcomes are those that affect cognition, including things like confusion and memory loss, along with more physical issues such as hypertension (high blood pressure). Indeed, older adults who subjectively report increased frequency of confusion and memory loss (referred to as subjective cognitive decline – SCD), and who have a history of hypertension may be at increased risks of dementia and other poor health outcomes. While exercise and movement have been found to improve cognition, evidence is limited in those with hypertension. Since hypertension is associated with cognitive impairment in older adults, a key question arises: can exercise be used to improve hypertension and thus SCD in older adults?
A recent publication co-authored by a group of researchers at Western University asked this very question. The articles importance can be noticed within its potential implications. Mainly, we know that there are more aged individuals than ever before. While this signifies that people are generally living healthier and longer lives, it also suggests that this large, aged population may have SCD and could potentially decline further into Alzheimer’s disease or dementia, overwhelming the care systems currently in place. If exercise can significantly improve hypertension and slow cognitive decline, then it can be a first step towards an integrated health plan for older adults aimed at combating and slowing SCD.
The authors addressed this question by selecting 128 older adults (> 55 years old) with a history of hypertension and SCD. Participants were prescribed either a high-intensity interval training (HIIT) or a moderate-intensity continuous training (MCT) workout regime. The difference between these exercises is their intensity, with HIIT being known to provide similar or greater cardio improvements compared to MCT – that is, HIIT will get your heart pumping more. Each group received 45 minutes of either HIIT or MCT for 3 days/week for 6 months. Measures of global cognitive function (memory, reasoning, concentration, and planning), lower-level cognitive processes (visual attention, task switching, and processing speed), cardiorespiratory fitness, and blood pressure were taken before the study, and then 6 months later.
Both the HIIT and MCT group had no major changes in global cognitive function when comparing scores taken before and after the study. However, improvements within each group were found for processing speed and task switching/cognitive control, suggesting that both types of exercises can improve some aspects of cognition in older adults.
No improvements were seen for systolic blood pressure (the force your heart exerts on the walls of your arteries) or resting heart rate in both groups. However, participants in the HIIT group who had a high systolic blood pressure (and likely hypertension) at the beginning of the study saw improvements after 6-months. Finally, large improvements were seen in cardiorespiratory fitness and diastolic blood pressure (pressure in your arteries when your heart is at rest) in both HIIT and MCT groups. Exercise (particularly HIIT) can serve to improve blood pressure and is particularly effective in those with hypertension, while simultaneously improving the capabilities of the heart and lungs.
These findings could be useful for future research and health planning for older adults. Consistent exercise for at least 6 months could improve processing speed and cognitive control, and the effects on other aspects of cognition may improve if the regime is used for a longer time, although this requires further investigation. Furthermore, HIIT style exercises can serve to lower blood pressure (especially if it is high) and improve cardiorespiratory function, both of which may reduce cognitive decline and the risk of dementia. Encouraging older adults to exercise more and for longer periods of time could slow the rate of SCD, allowing our healthcare systems to adjust to a rapidly aging population, so that we can provide the best care possible to the individuals that need it.
In many ways we are like the houseplant, both moving to get our necessities. Yet for us, movement is not just a vehicle to survive each day, it is a preventative measure that we can use to increases the chance that we may have good health in the near and long future. So, do your future self a favour and get moving!