COMMENTARY

A Prescription to Move: Giving Exercise Its Due

Carl J. Lavie, Jr, MD; Steven N. Blair, PED

Disclosures

January 08, 2015

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Carl J. Lavie, Jr, MD: I am Dr Chip Lavie. I'm a preventive cardiologist at the Ochsner Clinic in New Orleans, Louisiana, and I am here today with Dr Steve Blair from the University of South Carolina. He is well known for being the lead investigator of the Aerobics Center Longitudinal Study, from when he was at the Cooper Clinic. We are here today to discuss a running study that Dr Blair invited me to help with, which was published recently by lead author D.C. Lee and colleagues.[1]

This study had 55,000 people with 15 years of follow-up, and 13,000 runners were compared with 42,000 nonrunners. The findings showed that runners had a 30% reduction in mortality and a 45% reduction in cardiovascular mortality, on average, with increases in life expectancy of 3 years for mortality and 4.1 years for cardiovascular mortality. Those are pretty impressive results.

Steven N. Blair, PED: You would be hard pressed to find many other interventions that have an effect of that size. It is impressive.

Dr Lavie: Some people criticized the fact that we used relative risk reductions, but the fact that we showed improvements in life extension makes that a nonissue.

Dr Blair: It was not much of an issue with me. I am an epidemiologist. I live with relative risk and reductions and odds ratios and such, and they are pretty important.

Dr Lavie: There was no question that we were dealing with a relatively low-risk, healthy population for the most part, but still, even this healthy population derived tremendous benefit from running.

Dr Blair: And it didn't take a lot—just 6 miles a week for a huge benefit.

Dr Lavie: That was the most impressive finding. Most people would think that runners would have a better clinical prognosis than nonrunners. The fact that they are able to run means that they are somewhat selected. Maybe the running that they do from the exercise and fitness standpoint is going to help protect them more. So, just showing a benefit in the runners was not as big a surprise, but what we showed with dosing was very impressive.

We had 13,000 runners, divided into quintiles of about 2700 each, so they were quite statistically powered. We showed that the lowest quintile (who ran fewer than 6 miles, or less than 52 minutes per week, running 1-2 times weekly) had the maximal prevention in terms of mortality and cardiovascular mortality, and benefits equal to those of the second, third, and fourth quintiles. They had a slight trend toward a better effect than quintile 5, although not statistically better. That is a very important take-home message.

Dr Blair: These were not 4-minute milers. They did not have to run fast. A few miles at a moderate to slow pace produces these huge benefits.

Dr Lavie: When people reported their speed, it did seem that those who ran a little bit faster had a slight trend toward improved mortality, but it was not statistically significant. These were on average 40-year-olds running 10- to 11-minute miles. They would not be winning any races with those times, but they were getting maximum benefits for mortality and cardiovascular mortality.

You have probably published the most in the world of fitness, and many people consider you the grandfather of aerobic fitness research. You have shown how fitness is a strong cardiovascular risk factor and how protective high levels of fitness are.

This is one of the few examples where there wasn't a direct relationship between fitness and prognosis, because clearly the people who ran more (the higher-mileage people) were a little bit fitter and you saw a progressive increase in fitness with more running.

Dr Blair: It isn't much different from other studies where we looked at the relationship between measured fitness and various health outcomes. The biggest benefit is just getting out of that bottom group. It is not completely flat after that, but getting out of that bottom 20% is the important thing.

Dr Lavie: Often, you have defined the "fit" group as the people who weren't in the bottom 20th percentile (or tercile) of fitness for age and sex, so that is a good point. The runners, as a whole, were already fit. They already had estimated exercise capacities of more than 10 METS (metabolic equivalents). Those who ran more were statistically higher, but that didn't produce any additional mortality or cardiovascular mortality benefit.

Dr Blair: Exercise is good for you—even running in low amounts.

Dr Lavie: The other interesting thing is that the amount of running was well below the national guidelines. The guidelines say that individuals should be doing 150 minutes weekly of moderate activity, or 75 minutes of vigorous activity. Running is a vigorous activity, but in this study, less than 52 minutes produced a maximum benefit.

Dr Blair: I have said for years, and the guidelines now say, that something is better than nothing—so 75 minutes of vigorous or 150 minutes of moderate intensity are targets, just like cholesterol or blood pressure. What about those targets? Those numbers are targets that have been created on the basis of evidence. If you don't quite get to target but you are close to it, you are still going to get some important benefits.

Dr Lavie: That is a very good point. With running in particular, you appear to get the maximum benefits at very low doses. Obviously, many people cannot run. As people get older, it is hard to run. They may not be fit enough to run. They may have knee injuries, back situations, or hip situations, so many people have to do another form of exercise, and the most common one that people do is walking.

Dr Blair: You are talking about your old, fat, 75-year-old friend here.

Dr Lavie: I wasn't trying to throw stones at anyone in the room.

Dr Blair: I can still run a little bit if it is flat or downhill, but, no, at my age it is mostly walking. I have run many marathons, and even a 50-mile race, but as you get older, walking is probably what you are going to have to do to get a lot of benefit.

Dr Lavie: Dr Wen had a Lancet[2] study from 2011 with more than 400,000 participants from Taiwan. What got the headlines in that paper was the fact that all it took was 10-15 minutes of exercise to yield mortality benefits. He wrote an editorial that accompanied our article,[3] and he included his figure of running and walking showing that 5 minutes of running was equal to about 15 minutes of walking (3:1) or 25 minutes of running was equal to 105 minutes of walking (4:1). Still, they showed that you can get the same mortality benefit from walking as you can from running. It just takes more minutes to get the same effect.

Dr Blair: I give a lot of lectures in many places around the world, and I don't know how many thousands of times I have been asked, "What is the best exercise?" The best exercise is the one you will do. If it is shuffleboard or jump rope or swimming or playing tennis, it is doing something. The most common exercise, for most people, is walking, and running is common as well in many countries, but it is what you will do. Do something.

Dr Lavie: From a practical standpoint, it is going to be much easier and much more practical for people to walk than to tell people to run. The nice thing about running, though, is that it would be considered a vigorous activity. Many people in my practice—and we hear this all the time—is that the obstacle for many people is that they don't have time to exercise. Everyone is busy. Everyone is swamped, and so time is the factor.

The nice thing about our study is that we showed that you can get the maximal benefits with fairly small amounts of time. Running is very efficient. Someone can do 10-minute runs five times a week or 20-minute runs two or three times per week, and many people would have time to do that.

Dr Blair: There is another factor there, and that is if you do that 10-minute run in August in New Orleans, you have to factor in the time it takes to shower, and get dressed to go back and see your patients. If you are walking today in Chicago, I don't think you need a shower after you go for your walk.

Dr Lavie: That is a very good point. The other thing is there are some data that a little bit of alcohol is also protective against cardiovascular disease, so in New Orleans, we could perhaps say that you could run from bar to bar and produce some substantial cardiovascular benefits.

But this is very exciting research for people. Many other things will come out of these data, such as the prevention of diabetes and the effects in hypertension. We probably also are going to look at the very high exercisers, the high runners, to see whether there is even some possible loss of benefit.

There are many things more that we can do with this large data bank, but the biggest message that we have right now is the profound benefits, and the types of benefits for runners compared with nonrunners. Considering that we adjusted for other types of physical activity and other risk factors, such as smoking, hypertension, diabetes, and being physically inactive, not running was almost equal to many of those risk factors. So running produced substantial benefits for long-term prognosis.

Dr Blair: Our message to all the clinicians is to be sure that you at least bring up exercise at every patient visit, asking, "Are you doing something?" I don't expect clinicians to be personal trainers and help people exercise, but they should get it on the patient's agenda. Then if they need a personal trainer, find someone you can refer them to, or maybe suggest they take a 10-minute walk or run before breakfast.

Dr Lavie: We had a big paper on this in the Mayo Clinic Proceedings[4] last December—with your friend from Europe, Dr Vuori; you; and I—on promoting physical activity throughout the healthcare system. We should take that a step further and say that exercise or physical activity should be a vital sign, just like pulse and blood pressure and respiration. We need to get people to ask about it, record it in the medical record, and promote physical activity.

Dr Blair: Yes, absolutely.

Dr Lavie: It has been a pleasure to discuss this topic today. We are very excited about the response that our paper received from clinicians, cardiologists, general physicians, and the lay public. It is a very important topic and the biggest contributor to fitness is physical activity. We need to promote physical activity throughout the healthcare system, and it starts with each clinician in the office with each patient.

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