Exercise as it relates to Disease/The impact of low and moderate intensity exercise on blood pressure in older people

This page is a critique of the article ' The effects of aerobic exercise and T'ai Chi on blood pressure in older people: results of a randomised trial' written by Deborah Rohm Young, Lawrence J. Appel, SunHa Jee, and Edgar R. Miller III. Conducted by medical professionals at the Johns Hopkins Medical Institution.

What is the background to this research?
Blood pressure is measured in millimetres of mercury (mmHg) and it is the force of the blood pushing against the walls of the arteries. The focus of this article is on the effects of moderate and low intensity exercise on high blood pressure (hypertension) in older adults. Hypertension is a condition in which the force of the blood against the artery walls is too high which can lead to health conditions such as heart disease and stroke if left untreated. Hypertension can be treated with maintaining a healthy lifestyle of physical activity, maintaining a healthy weight, and eating a healthy diet.

The goal of this article is to determine if light-intensity exercise has the same health benefits on reducing blood pressure as a moderate-intensity exercise program. Very little has been done on examining the effects of light-intensity exercise such as T’ai Chi on blood pressure but previous study has shown that moderate-intensity exercise has had a similar effect on blood pressure as high-intensity exercise in middle-aged and older adults.

Where is the research from?
This research is from the journal of the American geriatrics society, volume 47(3), pp 277-284, and was conducted in 1999. The research was conducted in a suburban clinic at the Welch Centre for Prevention, Epidemiology, and Clinical Research, located at the Johns Hopkins Medical Institution in Baltimore, Maryland and contributions from Yonsei University located in Seoul, South Korea.

The authors of this article all have 10-20 years of experience in the field of cardiovascular health, making them reputable in this area.

What kind of research was this?
The study conducted was a randomised clinical trial, where participants are divided into separate groups to compare different treatments. The benefits of a randomised clinical trial are that participants are split randomly into groups meaning that results can be compared more fairly and at the time, the better treatment is not yet known.

What did the research involve?
The research was a 12-week study where 62 participants were randomly assigned into two equal groups of 31, with one group being assigned to moderate-intensity aerobic exercise and the other group, light-intensity T’ai Chi exercise. The participants were recruited from mass mailing to registered voters, mailings to previous study participants, advertisements in newspapers, and presentations at local senior centres.

Of the 62 participants in the study, 49 were female with a split of 25 of 31 in the moderate-intensity aerobic exercise group and 24 of the 31 in the low-intensity T’ai Chi exercise group. The eligibility of participants allowed in the study was based on their age being between 60-80 years; their average systolic blood pressure being between 130-159 mm Hg; their diastolic blood pressure being less than or equal to 95 mm Hg; less than 10 minutes of vigorous exercise per week; and personal physician approval.

The participants were required to complete a 12-week aerobic exercise program or a light intensity T’ai Chi program, where the goal was to exercise four days per week, 30 minutes per day. Each participant had follow-up visits every two weeks where blood pressure, and weight were measured for comparative results.

Strengths of the study:


 * Used specific criteria to test the efficiency of the study with participants having higher levels of blood pressure.
 * Regular follow-ups allowed for better comparative data collection.

Limitations of the study:


 * There was a small sample size due to the eligibility criteria and due to lack of interest in the study.
 * There was no control group meaning that the only comparison was between start point and follow-up sessions.
 * Only a short-term study meaning that long-term changes in results cannot be measured.
 * Participants did not always adhere to the specific intervention study as they ether did not attend exercise classes or over-exercised.
 * Not all participants finished the study due to either health issues or dropping out of the study and less than half of the follow-up blood pressure measurement visits were done on the day of exercising.

What were the basic results?
Key results that were found for this study include:


 * Significant reductions in systolic blood pressure after the first six weeks from first blood pressure measure.
 * Significant increase in time spent doing moderate activities, and leisurely walking from the aerobic exercise group.
 * The T’ai Chi group had a significant increase in the moving index.

As shown in the results above, the participants showed an improvement in their systolic and diastolic blood pressure with a decrease in their mm Hg across the 12 week exercise programs

What conclusions can we take from this research?
In this research, it was found that T’ai Chi had a similar effect of reducing blood pressure to that of moderate-intensity aerobic exercise. This can lead to significant changes in treating high blood pressure with low-intensity exercise as many older people have trouble with participating in moderate-intensity exercise. It can also lead to a higher promotion of low-intensity exercise programs such as T’ai Chi to reduce blood pressure as many older adults have had limited or no experience with exercise and may find moderate-intensity exercise impractical. In conclusion, low-intensity exercise can have similar health benefits to that of moderate-intensity exercise and can help in the reduction of blood pressure in older adults.

Practical advice
High blood pressure is a preventable disease, that can be prevented and treated. Unfortunately risk factors such as age and genetics contribute to a higher prevalence in individuals.

Prevention and treatment measures:


 * Regular physical activity
 * Eating a healthy diet
 * Maintaining a healthy weight
 * Limiting alcohol consumption
 * Not smoking

Further information/resources
For people living with high blood pressure, information can be found on these sites:


 * Mayo Clinic – High blood pressure (hypertension)
 * MedlinePlus – High blood pressure
 * Health Direct – What is a healthy blood pressure?

Information linked to prevention and treatment of high blood pressure:


 * MedlinePlus – Blood pressure medicines
 * MedlinePlus – How to prevent high blood pressure