Dr. Paul D. Thompson, MD, discusses how much weekly exercise he recommends, why the gains flatten at high levels of activity, why he advises cardiac rehab after a heart attack, and what he advises when a rehab program is not an option.
Heart Attack Recovery and Exercise: Cardiac Rehab, Weekly Targets, and Diminishing Returns
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- Benefit without getting in shape
- A weekly exercise target
- Where extra exercise adds little
- Why cardiac rehab comes first
- When cardiac rehab is not possible
- Full Transcript
Benefit without getting in shape
Exercise after a heart attack raises a practical question: how much activity is enough? Asked this by Dr. Anton Titov, MD, cardiologist Dr. Paul D. Thompson, MD, starts from a broader point. A person does not have to get in shape to benefit, he says, because many of the good effects of exercise are small changes repeated day over day.
Glucose, for example, goes down the day after exercise. With an exercise session every day, he explains, glucose and blood pressure come down. Getting in shape is not required, in his words, but exercising is.
A weekly exercise target
A weekly target is how Dr. Thompson frames the recommendation for lowering heart disease risk: 150 minutes of moderate exercise, such as walking at a brisk, good pace, or 75 minutes of vigorous exercise, such as jogging. He points out that the 150 minutes are counted per week, not per day, and he treats these amounts as the minimum he recommends.
Where extra exercise adds little
Diminishing returns are central to his description of exercise and heart disease risk, which he calls a U-shaped curve. Risk is highest among people who do nothing. The first step, from nothing to something, gives a big reduction; after that, the decline softens, which he calls an asymptote.
For someone already doing a lot of exercise, Dr. Thompson says, doing a lot more adds little benefit. He also notes that there seems to be a little rise at the far end of the curve with tons of exercise.
Why cardiac rehab comes first
Cardiac rehab is where Dr. Thompson says people should go after a heart attack. He describes these exercise programs as excellent. The nurses and exercise staff who run them advise on how hard to push, help with the other risk factors, and check on progress to make sure the person does not need to be referred back to the doctor. He calls these his general rules of thumb.
When cardiac rehab is not possible
Without access to cardiac rehab, his advice follows the recommendation for the general public: 150 minutes of moderately vigorous exercise or 75 minutes of vigorous exercise. He adds one requirement: the patient should first have the doctor's permission after the heart attack.
Full Transcript
Dr. Anton Titov, MD: Exercise and heart disease, too much exercise after a heart attack. You were senior author of an analysis of running and walking in heart attack survivors. Heart disease deaths were lower with more exercise, but the benefit faded at the highest levels. On your blog you wrote that most health benefits of exercise come at low levels. Professor Thompson, how much exercise is enough for a healthy heart? Where do the benefits of exercise level off?
Dr. Paul D. Thompson, MD: So you do not have to get in shape to get the benefit of exercise. We think a lot of the good things that happen with exercise are small effects repeated day over day. Your glucose goes down the day after exercise.
Dr. Paul D. Thompson, MD: So if you lower your glucose a little bit with an exercise session every day, you lower your glucose level, your blood pressure. So you do not need to get in shape, but you do need to exercise. The recommendations to use exercise to lower the risk of heart disease go something like this: 150 minutes per week, not day, 150 minutes per week of moderately vigorous exercise, moderate exercise, such as brisk walking, walking right along, walking with a good pace, or 75 minutes of vigorous exercise like jogging, okay? 150 minutes, 75 minutes per week of moderate or vigorous exercise.
Dr. Paul D. Thompson, MD: There is actually what we call a U-shaped curve. What does that look like? The people with the highest risk of heart disease are right here.
Dr. Paul D. Thompson, MD: They do nothing. Those are your so-called couch potatoes. I am not picking on you couch potatoes; I am just giving you a name.
Dr. Paul D. Thompson, MD: As you get some exercise, the reduction is actually pretty steep. Going from nothing to something gives you a big reduction, and then that decline kind of softens out. We call it an asymptote.
Dr. Paul D. Thompson, MD: Sharp and then smoothing out. So when you get down here, a lot of exercise, you do not get a lot of benefit from going from a lot of exercise to a lot more exercise. There actually seems to be a little rise on this far end.
Dr. Paul D. Thompson, MD: You come down and then just go up a little bit if you get tons of exercise, something we talked about later. So what I recommend people do is that they do a minimum of 150 minutes per week of moderate or 75 minutes per week of vigorous exercise. Now, what about after a heart attack?
Dr. Paul D. Thompson, MD: After a heart attack you should go to cardiac rehab. There are exercise programs set up for people who have had a heart attack, and these are excellent programs. Why?
Dr. Paul D. Thompson, MD: Because the nurses and exercise people who do it can advise you on how hard to push yourself, they can advise you on dealing with the other risk factors, and they can see how you are doing to make sure you do not need to be referred back to your doctor. But those are my general rules of thumb. If you have had a heart attack, you need to go to cardiac rehab.
Dr. Paul D. Thompson, MD: Now, let us suppose you cannot go to cardiac rehab. It is the same sort of recommendations we give for the general public, which is 150 minutes of moderately vigorous or 75 minutes of vigorous exercise, once you have your doctor's permission after your heart attack.