Can Too Much Exercise Damage Your Heart?

Extreme exercise may be just as bad for you, if not worse, than not enough exercise. There is a "Goldilocks zone," beyond which the damage that occurs from exercise will outweigh the benefits.

Exercise Is Good Medicine, But Only at the Right Dosage:

Fitness research confirms that physical activity is one of the best "preventive drugs" for many common ailments and diseases. This is true from psychiatric disorders to heart disease, diabetes and cancer.

One meta-review of 305 randomized controlled trials comparing the effectiveness of exercise as compared to drug interventions on mortality outcomes found "no statistically detectable differences" between exercise and medications for pre-diabetes and heart disease. This is remarkable, since properly done exercise has no side effects.

Proper exercise helps normalize your glucose, insulin and leptin levels. This are important factors for optimizing your overall health and preventing chronic disease.

Another way in which exercise promotes good health and longevity is by forcing your mitochondria to work harder, thereby producing more mitochondria to keep up with your body's heightened energy requirements. This also slows down of your biological aging process.

Chronic inactivity has been shown to be an independent risk factor of chronic disease and early death, but the evidence also shows that going exercise overboard does put your health at risk.

One of the risks of excessive high intensity cardio is you can develop an enlarged heart that leads to something called diastolic dysfunction and heart failure.

What's the Ideal Dose of Exercise for Optimal Health & Longevity?

Research has shown that once you reach 40 to 50 minutes of daily vigorous exercise, or just over an hour of moderate exercise, the benefits from your efforts plateau and further efforts do not convey additional improvements in life expectancy.

One of the largest, longest, and most recent studies to shed light on this "Goldilocks zone", found that those who walked or engaged in other moderate-intensity exercise for around one hour per day, seven days a week, lowered their risk of premature death by 39%, as compared to non-exercisers.

When it comes to endurance cardio, previous research has shown that to optimize the health benefits from running you'll want to run 10 to 15 miles per week. Once you reach 25 miles or more per week, the benefits again disappear.

Also, if you distance run too fast, over 8 miles an hour, the benefits tend to go away. Lastly, if you run seven days a week, the benefits also disappear, since you body can't ever recover. The ideal amount was found to be a 30-minute run, two to five days a week.

So, the key really is moderation, in terms of intensity, duration, and frequency. The human body simply wasn't designed to engage in long-term extreme athletic performance.

I have advocated High Intensity Interval Training (HIIT) and I still do. This is not a contradiction. The key to HIIT is that you are not doing it for a prolonged period of time. A peak 8 workout has only 4 minutes of high intensity exercise, which the body tolerates very well. The damage occurs when you push yourself too hard, for too long.

Move to Live:

Research has demonstrated that six hours of uninterrupted sitting counteracts the positive health benefits of one hour of exercise. So the foundation for good health is relatively constant or regular movement. Avoid sitting down as much as possible. Even just standing up produces beneficial biological effects.

Walking 7,000 to 10,000 steps a day will be better for your health than performing an optimal workout schedule and sitting for 8 hours a day.

How and Why Extreme Cardio May Damage Your Heart:

Extended extreme cardio sets in motion inflammatory mechanisms that damage and prematurely age your heart. Your heart pumps about 5 quarts of blood per minute when you're sitting. When you're running, it goes up to 25 to 30 quarts and it wasn't designed to pump this amount of blood for hours on end, day after day.

When pushed in this way, your heart basically enters a state of "volume overload" that stretches the walls of your heart muscle, literally breaking fibers apart.

Failure to fully recover between runs compounds the problem. Many endurance athletes live in a perpetual post-workout state, which resembles chronic oxidative stress. This repetitive and unrelenting damage to the heart muscle increases inflammation that leads to increased C Reactive Protein levels. Arterial plaque then forms, as your body's way of "bandaging" the lining of your inflamed arteries.

Over time, as more damage is inflicted, the heart enlarges to a state of cardio-hypertrophy and also forms scar tissue called cardiac fibrosis. MRIs of long-time marathoners reveal abundant cardiac scarring.

Scientists have also measured elevated cardiac enzyme levels after extreme exercise and it is similar to the levels just after a heart attack. This can only mean that this type of exercise is damaging the heart. While you may think that you are super fit, you run the risk of dropping dead from cardiac arrest. The irony is that extreme athletes think that they are healthy.

7 Signs You May Be Overdoing It:

While HIIT is inherently safer than endurance cardio, it's very important to carefully consider the frequency of your sessions to give your body enough time to recover. If you don't, HIIT also has the potential to do more harm than good. To maximize your workout efforts, you'll want to push hard enough to challenge your body at your current level of fitness, while allowing your body to fully recuperate in between sessions.

If you're doing high intensity interval exercises, it's NOT recommended to do them more than three times a week. I prefer twice a week.

If you're unsure whether you may be pushing yourself too hard, the following seven symptoms may signal that you need to cut back a bit and allow your body to recover:

1. Exercise leaves you exhausted instead of energized

2. You get sick easily (or it takes forever to get over a cold)

3. You have the blues

4. You're unable to sleep or you can't seem to get enough sleep

5. You have ''heavy'' legs

6. You have a short fuse

7. You're regularly sore for days at a time

How Do You Test For Heart Damage?

If my patients are concerned about how much damage has been done to their heart, the test that I recommend is the B-Type Natriuretic Peptide Test (BNP). This tests for a 32 amino acid polypeptide that is secreted from the ventricles or lower chambers of the heart in response to changes in pressure that occur when heart failure develops and worsens. The older you are, the higher your BNP tends to be. A BNP levels below 100 pg/mL indicates no heart failure. I prefer it to be under 40. A BNP levels of 100-300 pg/mL suggest heart failure is present. A BNP above 900 pg/mL indicates severe heart failure. You should consult your doctor to make sure that your heart is healthy enough, prior to starting any new exercise program.

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