Exercise effective at cutting high blood pressure

19 December 2018

A major new review published in the British Journal of Sports Medicine has shown that exercise is very effective at lowering blood pressure. Researchers from the London School of Economics and Political Science looked at the results of over 200 studies looking at medicines and 200 looking at exercise with 40,000 people in total. They found that structured exercise programmes such as walking, jogging and gym sessions, all worked well in lowering high blood pressure. 

The results suggest that exercise could even be as effective as medicines, but there are no studies available directly comparing medicines and exercise, highlighting an important area for research. 

The researchers said patients should not immediately ditch their drugs on the basis of the findings.  Lead author Dr Huseyin Naci, Department of Health Policy, London School of Economics and Political Science, said: “We don’t think, on the basis of our study, that patients should stop taking their antihypertensive medications. But we hope that our findings will inform evidence based discussions between clinicians and their patients.”

Katharine Jenner, CEO of Blood Pressure UK agrees; “Exercise is very important for improving overall health as well as lowering blood pressure.  If you have raised blood pressure (more than 120 over 80 and less than 140 over 90 (120/80-140/90)), then regular endurance exercise such as running, walking, cycling or swimming and a general healthy lifestyle, could help prevent your blood pressure from getting high enough to need medication.  However for many people with high blood pressure (140 over 90 (140/90) or higher), taking on an intense exercise regime should be done with caution and on the advice of your GP, and certainly alongside your medication until you review your treatment plan with a healthcare professional .  The first step should be to find out your blood pressure numbers, so you can make an informed decision.” 
  

We caught up with the authors on what the study means for people with high blood pressure

Dr Huseyin Naci explains what this study shows, why it’s important, and what the next steps should be.

Why did you decide to run this study?

There’s a lot of research evidence on how much drugs lower blood pressure, and there’s evidence that exercise lowers blood pressure, but we weren’t aware of any comparisons between the two. So, we wanted to compare them for the first time.

So, this is the first study of its kind – comparing exercise with medicines for treating high blood pressure? 

Yes, but it’s important to highlight that it’s not a direct comparison – we have to rely on indirect sources.

Because there is a lot of evidence on how drugs compare to no drugs, and how exercise compares to no exercise, we could use the no-intervention arms of those studies* to do an indirect comparison of drugs and exercise.

How did you run the study?

We identified all the randomized controlled trials evaluating the effect of exercise on systolic blood pressure. Then separately we identified all of the trials looking at drugs for lowering blood pressure. Then we searched for any studies that may have compared exercise to drugs directly to make sure this hadn’t been done before, and we didn’t find any.

There were about 200 trials looking at drugs and about 200 for exercise. We extracted information from these studies, for example about the patients, how long the studies ran for, what the interventions were such as which drugs or type of exercise, and how much they lowered blood pressure. Then we used a technique called meta-analysis to synthesise the results.

What did you find?

We found that for people with high blood pressure, systolic blood pressure was brought down to the same level with exercise as it was with medicines.

The majority of exercise studies have been done in healthy people without raised blood pressure. When we focused on just those people with raised blood pressure, the exercise performed just as well as the drugs.

That’s very encouraging. What can we take from the results given that it’s not a direct comparison?

I don’t think anybody should stop taking their medicines who’ve been prescribed them by their doctor. What’s important is that hopefully GPs, health professionals and patients who’ve been told they should start taking medicines can now consider more carefully whether intervention with exercise could be suitable for them.

For example, would the patient be willing to go ahead with an exercise programme, are there suitable services in their area, and could they then delay taking medications by substituting them with exercise? They could then move onto medications if the exercise is not effective.

A term that’s coming up is ‘structured exercise’. Is there a particular type of exercise people should be doing?

We looked at four different types of exercise. The first is endurance such as walking, swimming, jogging and cycling. Then there’s strength or resistance training, like going to the gym and lifting weights. There’s also isometric exercises, and finally, a combination of strength and endurance training.

We didn’t identify a winner and concluded that they all seem to be effective. There have been a lot more studies on endurance exercise than the other types, but we’re seeing more on resistance as well. So, we can be more confident with the results for endurance and resistance training, but all types of exercise were effective.

In terms of amount, the studies in our review had to include at least four weeks of exercise and at least two to three sessions per week, in varying duration and intensity.

You’ve mentioned the indirect comparison, and that many people in the exercise group didn’t have high blood pressure. Are there any other limitations of the study?

The types of people who take part in exercise trials are very different to those who take part in drug trials. Drug trials are done by pharmaceutical companies, they have more resources and tend to be better conducted. Exercise trials are done on a smaller scale. They have fewer people and may have more limitations in their design and how they’re conducted.

That’s why we’re very modest in our interpretation of the results. We need more research on how well exercise compares to medications.

What would be a good next step?

I think it’s critical that we do a randomized control trial comparing exercise to drugs directly in people with high blood pressure, who haven’t started taking medications yet. We can then find out if people can avoid or delay medications by substituting them with exercise.

Why did you focus on systolic blood pressure and not diastolic as well?

Systolic blood pressure is much more widely reported in studies than diastolic. They’re both important, but systolic blood pressure seems to be better correlated with cardiovascular disease outcomes in the future.

What conclusions could you draw about exercise based on this research?

Exercise seems to have all sorts of benefits. If you look at all the literature, it shows benefits for mental health and all sorts of other physical health measures. So, people will benefit in general from exercise. And the more you do, the better, it seems.

We focused on a very narrow but very important question about systolic blood pressure, because it’s the leading cardiovascular disease globally. So, if we can see benefits of exercise with blood pressure, we can expect major health benefits across the board at a population level.

Finally, are there any other implications or conclusions you can draw from this study

Broadly speaking, what’s interesting to us as researchers is that we have a body of literature focused on the effects of drugs, driven by the pharmaceutical industry. And this is a really large number of well-conducted studies. Then we have a separate body of literature from academics looking at exercise, and we’re not seeing any links between the two areas of research. This is a huge limitation.

This is very much limiting or restricting doctors and the health care profession to focus on drugs alone or exercise alone – the two are not connected. This is a major bridge that we need to build.

*No-intervention arm – the group of people in a study who had no treatment or lifestyle changes]

** Randomised controlled trial – a type of scientific study which compares a treatment of lifestyle change with a control group who have no treatment or changes. This type of design allows researchers to see how well a treatment or change works. 

Read more

You can read the study for free online. 

Read an analysis of the research from the NHS’s Behind the Headlines. 

You can also find coverage of this story in the Telegraph online. 

For more information and advice on how exercise can help to lower your blood pressure, please visit our exercise and activity page where you can also download our 'Healthy Lifestyle and blood pressure' booklet.