The High-Performance Heart

High Performance Heart

This feisty, magnificent muscle is made to move us in many ways — physically, biochemically and mental-emotionally.

The human heart is a high-performance powerhouse, designed to beat billions of times during a lifetime, remain disease-free and provide the spark for all human activities both conscious and unconscious.

For most of us, the heart we are born with is the only one we will ever have — a good reason to take care of it. We must walk it like a dog, run it like a horse, rest it like a lover, and feed it well both physically and emotionally so it thrives as it was meant to.

This of course is easier said than done in a society where heart-shaped candies are symbols of affection even when we know ingredients such as sugar can have deadly effects. While most premature cardiac deaths due to unhealthy hearts are preventable, it would appear we have a love-hate relationship rather than caring for a cherished body part we ponder quite often, much like our bellies (more on that later).

For the past 40 years I’ve been monitoring and studying heart-rate patterns in many types of people in all walks of life — from those just getting off the couch and wanting to lose weight or in rehabilitation, to Olympic athletes.

Poor heart function isn’t always obvious — the first sign of heart disease is all too often death, even in highly trained athletes. If we could see our hearts, and the damage done, we might treat our cardiac currency better.

If we could view our own hearts, what we would see is that surrounding the heart, cuddling it, protecting it, cushioning it, is an important layer of pericardial fat. This healthy fat also is a key energy source for the heart muscle and its continuous contractions, and for the local vessels bringing blood to and from the heart.

Too little or too much pericardial fat poses a problem. While there may be a growing population of underfat people, even in developed countries — those who are obsessed with body image, are malnourished and even overtrained athletes — there’s also a prevalence of people who are overfat.

The excess accumulation of epicardial adipose tissue — called EAT — is considered an independant cardiovascular risk factor, as dangerous as high blood fats and hypertension.

Excess fat around the heart impairs its function many ways. Even if we can’t see it, we can get a good idea of how much is there by observing the fat in the pericardium’s embryological cousin — the abdomen, which shares many features.

As we know so well, excess abdominal body fat impairs health and fitness. This excess adipose can trigger chronic inflammation, the early stage of most diseases. Too much ab fat can also increase carbohydrate intolerance (insulin resistance), triggering higher levels of carbohydrate foods, even the healthy ones, to convert to stored fat, all while reducing fat-burning. No surprise that heart disease is a leading cause of death worldwide.

So if you want a sense of what the fat is like surrounding the heart, take a look at your belly; better yet, measure it. In addition, pericardial fat can also be measured with an echocardiogram (along with other imaging technology such as MRI).

A recent study showed that low-carb eating was significantly better at reducing excess fat around the heart than a low-fat diet. Of course, that’s also the best way to get rid of excess abdominal fat.

Exercise as a form of fat-reduction is less effective than eating well — just burning calories may not reduce excess body fat, from the belly, around the heart or elsewhere.

Those who exercise are not immune to excess pericardial fat, and athletic performance is impaired by it. Tens of millions of runners around the world, for example, have been racing slower each year. This may be associated with excess fat around the heart, which reduces VO2max and impairs cardiac function. The result can be elevated exercise and competitive heart rate, slowing training and racing paces.

Many physically active people are unaware they have hearts that don’t work well. Or, they have signs and symptoms of heart problems that they ignore, such as abnormal blood fats (cholesterol and triglycerides), blood-sugar levels, and high blood pressure, or painful physical impairments ranging from seemingly minor injuries to serious disabilities.

Drug and health stores are full of products that supposedly help the heart, but in fact, most of these don’t and many can make it worse. The best remedies for heart health are simple — a healthy diet void of junk food but rich in healthy fats, proteins, vitamins and minerals, and other natural nutrients; physical activity that raises the heart rate without abusing it.

As a muscle, the heart needs exercise. But too much can kill. While the so-called athlete’s heart evolves from training, overdoing it hurts the heart. In association with rising stress hormones, this can even result in cardiovascular disease leading to sudden death — athletes may be seven-times more likely to die during activity than at rest. This mostly preventable problem in people seeking high levels of fitness at the expense of health occurs at all ages.

Stress in all its physical, biochemical and mental-emotional forms, has a major influence on heart health, with excessive levels associated with poor heart function and disease. Even if you are doing everything right with diet and exercise, too much stress can still sabotage your heart. Taking proper measures to manage stress, including making your own stress list, is important to developing a high-performance heart.

This poor health drama isn’t always entirely our own fault. Occasionally, perhaps more frequently today, some people are born with faulty genes. In addition, and more than any other time in human history, babies are born already overfat due to poor maternal nutrition. Now, many children are getting adult diseases, preceded by those early warning risk factors. This includes poor motor skills, important because they play crucial roles in physical, cognitive, and social development, and a reason these problems usually progress into adulthood.

Whatever circumstances you were born with, or wherever you are on your journey to better health and fitness, it’s not too late to take steps to improve your heart’s performance and to protect it from disease. These steps include improving your diet and nutrition, aerobic exercise and managing stress.

Want a high performance heart? Get healthy and fit — your heart will follow.


  • Maurine Lee says:

    I have been LCHF for 15 months now. I am also an ultra runner/walker. I’ve lost 65 pounds and my waist size is considered in the healthy range. That being said, all my blood test numbers improved except for cholesterol. I have what my doctor calls resistant cholesterol to weight loss and exercise. I really don’t like taking statins and have been reading that the use of statins is controversial. I’d be interested in what Dr. Maffetone thinks regarding this.

    • Hey, great topic for an article! Generally Dr. Phil thinks that statins have more drawbacks than benefits, but the most important takeaway is that your own cardiologist should have all the best data to advise you!


      • Maurine Lee says:

        Thanks for the response. I don’t see a cardiologist. I am 58 years old and run/speed walk ultramarathons for fun. I follow a keto lifestyle and eat pretty healthy. I only have a PCF and don’t know that I want to pay to see a cardiologist at this time. Given that I have a pretty clean bill of health right now, I’m going to go with my gut feeling. I’m averaging 55-70 mpw and have for a long time, so think that my instincts are safe for now.

  • David Guaglianone says:

    Hi Phil,
    Once again thank you for the great article! You have had a profound influence on my health and life. Thanks to you, I have been LCHF for two and a half years. Between the new diet and the MAF method, at 56 I feel better now than I did in my 40’s, and my wait is again what it was in my 20’s. Amazing!

  • Graeme says:

    Excellent article, I read it in conjunction with your Blood Pressure article of 2015. I have found it hard to reconcile my high blood pressure with a consistently low resting heart rate 50-55 bpm.
    Health care professionals in general don’t take the time to have a wider discussion, I will not pursue the carb side of things and see what difference it makes. Again thanks for all of this very accessible information.

  • Nathalie says:

    In my previous comment, I forgot to mention my husband is 48 years old. Thank you.

  • Nathalie says:

    Hi. Nice article. I have a husband, with no excess fat, who loves to train hard. Home crossfit, and high intense cardio workouts are his favorites. After an intense workout sometimes he feels a taste of blood coming from his throat. I question if that is healthy? Please share any article to answer that. Thank you.

  • Louis Raboin says:

    This is the best article I have read to this day. This is what exercise should be about ! Staying healthy for your entire life!! Thank You Dr Mafatone. I have read all your books and I believe in your aerobic training techniques. Louis Raboin

  • Please tell me what carbs we can and can’t eat. So confused with the plethora of crap information from sponsored sites with vested interests!

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