Can vigorous exercise help lower cognitive impairment risk?

High blood pressure occurs when the force of blood pressing against blood vessel walls gets outside of a certain range. It can lead to damaged blood vessels and increase people’s risk for heart problems and stroke.

A normal blood pressure reading is less than 120/80 millimeter of mercury (mmHg), and doctors may diagnose someone with high blood pressure when a systolic reading 130 mmHg or more or when a diastolic reading is 80 mmHg or more.

Previous research has also linked high blood pressure in midlife with a higher risk for cognitive disorders. The authors of the current study note that people with high blood pressure are at a higher risk for Alzheimer’s disease, vascular dementia, and mild cognitive impairment.

José Morales, MD, a vascular neurologist and neurointerventional surgeon at the Pacific Neuroscience Institute in Santa Monica, CA, not involved in the current research, explained to Medical News Today that:

“Hypertension damages the small blood vessels in our brain and also causes them to malfunction. This results in progressive damage to the brain, which in turn leads to cognitive impairment.”

The researchers who conducted the current study wanted to evaluate if vigorous exercise helped with the risk for mild cognitive impairment and probable dementia.

This study was a post hoc analysis using data from the SPRINT MIND STUDY, which formed part of the SPRINT trial. This trial involved over 9,000 adults in the United States who had high blood pressure.

At enrolment, participants were asked about the frequency of participating in vigorous physical activity. Vigorous physical activity was defined as activities that induced sweat, increased heart rate, or increased breathing.

Participants could pick their level of vigorous physical activity from the following categories:

1. rarely or never
2. one to three vigorous activity sessions a month
3. one vigorous activity session a week
4. two to four vigorous activity sessions a week
5. five or more vigorous activity sessions a week.

In the analysis, researchers divided participants into a low-vigorous physical activity group and a high-vigorous physical activity group.

The low-vigorous physical activity group had less than one vigorous activity session a week, and the high-vigorous physical activity group had one or more vigorous activity sessions a week.

All participants also underwent cognitive assessment tests, and covariates included components like age, education, smoking, use of antihypertensive medication, body mass index (BMI), and alcohol use.

The researchers excluded participants who had limited physical function or missing cognitive assessments, allowing them to include 7,670 participants in their final analysis.

The average follow-up time with participants was 4.5 years, and over this time, there were identified cases of mild cognitive impairment and probable dementia.

Overall, participants in the high vigorous physical activity group were at a lower risk for mild cognitive impairment and probable dementia.

The association was stronger among participants less than 75 years old at baseline, and Black participants. The association also appeared stronger in participants with prior cardiovascular disease.

Study author Richard Kazibwe, MD, from Wake Forest University School of Medicine in Winston-Salem, NC, noted to MNT that:

“Engaging in vigorous physical activity at least once a week may help slow cognitive decline in individuals with hypertension. This level of physical activity may offer protection against both dementia and mild cognitive impairment. The study is unique because it focuses on individuals with high-risk hypertension, a population more likely to develop cognitive impairment. Previous studies have not specifically addressed this group.”

According to Morales, “[t]his is an interesting study that demonstrates what many people with uncontrolled hypertension find counterintuitive.”

“Exercise helps to regulate our autonomic nervous system and reduces the impact of these vascular risk factors on our health,” he explained.

“People should be encouraged to see the impact lifestyle changes can have on modifying the consequences of vascular risk factors such as hypertension, as well as preserve brain health and functioning,” added Morales.

Despite the intriguing findings, this study does face some specific limitations.

First, some of the data came from participants’ self-reports, which means it can be inaccurate. Then, almost 65% of participants were white, and about 35% were women, indicating the need for greater diversity in future research and a limited ability to generalize the results.

The findings also cannot be generalized to groups with certain conditions not represented in the SPRINT study, such as those with diabetes. The exclusion criteria of the current analysis could also have impacted the results.

The authors further acknowledge that their study “likely lacked the adequate statistical power to detect the benefit of [vigorous physical actvity] on the risk of probable dementia.”

There is also a potential confounding risk, and researchers only looked at baseline data for vigorous physical activity. Changes in vigorous physical activity could have impacted cognitive outcomes.

Moreover, the researchers did not look at how moderate physical activity or the potential negatives of sedentary behavior could affect cognitive status. Finally, mild cognitive impairment “at the time of enrolment was not adjudicated,” which could have impacted the results.

Future research can allow for longer follow-up times to confirm the findings of this research. Kazibwe noted that future research could include “[s]tudies using device-assessed physical activity in large and diverse populations are needed to investigate the benefits of vigorous physical activity for protecting against cognitive decline.”