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Training the Forgotten Muscle: Your Heart

Training the Forgotten Muscle: Your Heart
by Dr. Clay Hyght

When we think of training to improve muscular performance, we’re probably all guilty of thinking of the skeletal muscles,
particularly the more showy ones. But contrary to popular dogma, neither the pecs nor the abs, nor the delts nor the
glutes are the most important muscles to train. Undoubtedly the most important muscle in the body is the heart. If
you disagree, listen to these stats.

According to the Centers for Disease Control and Prevention, 61 million Americans suffer from some form of heart disease. That’s about one out of every four people! On top of that, almost one million die each year from heart disease, making it the number one killer in America. To look at that yet another way, one person (in the U.S. alone) dies of heart disease every 33 seconds. Yep, roughly 20 people will lose their lives to heart disease while you’re reading this article!

There is a silver lining to this cloud, however. There are many things we can do to dramatically decrease our risk of suffering an untimely demise due to heart disease. Let’s take a closer look at how to do just that.

Training for Heart Health
According to researchers at the Harvard University School of Public Health, running for just 60 minutes per week reduced the risk of heart disease by 42%. Weight training for at least 30 minutes per week (not very long if you ask me) decreased that risk by 23%. Brisk walking for 30 minutes per days decreased the risk by 18%. According to this study, which followed almost 45,000 men, it’s not just aerobic exercise that’s good for the ole ticker.

Weight training is not only good for those showy skeletal muscles, but also for the neglected cardiovascular system. Much of that benefit is thought to come from the well-accepted fact that weight training improves the muscles’ ability to absorb glucose from the blood stream. We nerds call that improving insulin sensitivity. This is great news for type II (adult onset) diabetics, since this type is essentially caused from a decrease in insulin sensitivity. Let’s get back to the heart of the matter.

Another interesting thing to note about that study is that it seems that the heart benefits and the intensity of exercise are proportional. In other words, the harder you work, the more benefit you’ll get. As a general rule, one should exercise in the range of 65 – 85% of maximum heart rate to obtain cardiovascular benefits.

To calculate this zone, simply subtract your age from 220. This gives you your age predicted maximum heart rate. Then multiply that number by 0.65 and 0.85 to give you your heart rate training zone. For example, if you’re 40 years old, your age predicted maximum heart rate is 180 beats per minute (220 – 40). Multiplying that by 0.65 (65%) gives us 117 beats per minute - the lower end of your training zone. Multiplying 180 by 0.85 gives us 153 beats per minute. Thus, a 40 year old should exercise at an intensity that causes his or her heart to beat somewhere between 117 and 153 beats per minute. You can either wear a heart rate monitor (available at most larger sporting good stores for well under 100 bucks) or place your middle and index finger on your radial pulse (located on the outside of your wrist, an inch or two up from the crease) for 15 seconds and multiply by four. I find it rather fun to exercise with a heart rate monitor. This lets you constantly know how hard you’re working and helps to pass the time.

So what kind of exercise is best for improving heart function and health? The good news is that virtually any kind of activity that gets and keeps your heart rate up will work. Running is one of the most obvious choices. However, one must consider the abuse that the ankles, knees, hips, and lower back may suffer after years of high-impact exercise.

If you do opt to run regularly, wear shoes with great support and consider logging some of your miles on the treadmill, which will reduce some of the impact. Though I’m certainly not against running (especially in moderation), I’d probably lean towards something less traumatic like one of the new elliptical trainers. Cybex makes a new piece of cardio equipment called and Arc Trainer that I’m really fond of. It seems to get your heart rate up really well but with virtually no impact.

As the Harvard study showed, lifting weights can certainly benefit the heart. However, because your heart rate does not continually stay in the “zone,” VO2 max does not improve as well with weight training as it does with steady state aerobic exercise. (For the record, VO2 max is a measure of how efficiently your body uses oxygen. Essentially, a higher VO2 max equates to a higher level of aerobic fitness.) An optimal heart healthy exercise program would combine both steady-state aerobic exercise and weight training. Performing 30 minutes of each, three times per week would do wonders for your health. Depending upon your goals, you could gradually increase from there.

Heart Adaptations
You may be wondering exactly how the heart responds to exercise. Good question. The primary way is by increasing the amount of blood that is pumped out with each contraction – called stroke volume. This, in essence, makes the heart more efficient, allowing it to pump the same amount of blood with less beating. Because of this, the resting heart rate of someone who is aerobically trained is typically less than that of a sedentary individual. For example, at rest, an athlete’s heart rate may be as low as 50 beats per minute. On the other hand, one who doesn’t exercise is more likely to have a resting heart rate of roughly 70 beats per minute. That’s 28,800 less beats per day that a trained heart has to beat to supply the same amount
of blood! 

 
Additionally, the size of the trained heart is often larger than that of the untrained heart. This is much like the increase in size that skeletal muscles incur as a result of weight training. Don’t be confused by the fact that some diseases (e.g. congestive
heart failure) can cause an enlarged heart. Echocardiograms (ECGs) and blood tests have confirmed that a slightly enlarged heart as a result of exercise does not indicate heart tissue damage. On the other hand, an enlarged heart that results from disease is certainly not good. This is again confirmed by an Italian study (Pelliccia A, Maron BJ. Athlete’s heart electrocardiogram mimicking hypertrophic cardiomyopathy) of over 1,000 athletes that showed that while over 40% of them had what would be considered abnormal ECGs, only 5% actually had structural cardiovascular disease. This has led to the term “athlete’s heart.” It’s important for physicians accessing heart health to understand these physiological adaptations that occur as a result of athletic training, in order to avoid falsely diagnosing heart pathologies.

Blood Tests
There are a few blood tests that your physician can order to pretty accurately access the health of your cardiovascular system. For starters, total cholesterol and its’ three primary subunits, HDL, LDL, and VLDL cholesterol should be measured. HDL cholesterol is considered the ‘good’ cholesterol while LDL is considered the ‘bad’. VLDL (very low density lipoprotein) is the primary transporter of triglycerides and is considered ‘bad’ like its’ brother LDL. It is currently thought that HDL (high density lipoprotein) is a blood protein that carries cholesterol away to be excreted, while LDL (low density lipoprotein) carries cholesterol that can easily be deposited into tissues and blood vessels.

It’s pretty well accepted that the ratio of total cholesterol to good cholesterol (HDL) is a better predictor of cardiovascular health than simply the total cholesterol. This ratio should be 5:1, while 3:1 is considered optimal (1). Triglyceride levels are also an important when accessing heart disease risks. Elevated serum (blood) triglyceride levels are associated with an increased risk of heart disease. These five values (total cholesterol, HDL, LDL, VLDL, and triglycerides) constitute what most doctors call a lipid profile or lipid panel, which is kind of a bare bones method of evaluating cardiovascular health.

According to the American Heart Association, a lipid panel should be performed every five years for adults over 20 years of age(2). If abnormal, your doctor may choose to perform the tests on a much more regular basis.

ATP III guidelines (2) for cholesterol, HDL, LDL, and triglycerides are listed below. 
Total Cholesterol
200 mg/dL: Desirable
200 – 239 mg/dL: Borderline High
240 mg/dL: High

HDL Cholesterol
40 mg/dL: Bad (Major Risk Factor)
40 – 59 mg/dL: Moderate
60: Good (protective against heart disease)

LDL Cholesterol
100 mg/dL: Optimal
100 – 129 mg/dL: Above Optimal
130 – 159 mg/dL: Borderline High
160 – 189 mg/dL: High
190 mg/dL: Very High

VLDL Cholesterol
25 – 50% of total cholesterol: Desirable 50% of total cholesterol: Undesirable (increased heart disease risk

)

Triglycerides
50 mg/dL: Normal
150 – 199 mg/dL: Borderline-High
200 – 499 mg/dL: High
500 mg/dL: Very High

Another fairly new method of evaluating heart disease risk is measuring levels of C-reactive protein (CRP). Many think this measure may even be more accurate than cholesterol levels when evaluating heart disease risk. Though high levels of CRP
can be caused by other pathologies (e.g. urinary tract infection), it can still be a valuable tool when combined with other known risk factors.

Nutrition
Fortunately, there are a number of dietary factors that reduce the risk of cardiovascular disease. One of which is to eat Omega-3 containing fish (i.e. Salmon) on a regular basis. Doing so just twice per week has been shown to significantly reduce the risk of death from heart disease (3). As an alternative, you could use supplements high in the Omega-3 fatty acids like fish oil capsules. Both of which should have a similar effect on heart health.

Another nutrient that is proven to reduce the risk of heart disease is fiber. A brand new study conducted by researchers at the U.S. Centers for Disease Control and Prevention (4) shows that fiber intake and levels of C-reactive protein are inversely proportional. In other words, the more fiber you eat, the lower risk of heart disease you’ll have. Now you have yet another reason to eat your fruits and vegetables.

Garlic and Niacin (vitamin B3) have both been shown to decrease cholesterol levels in a number of studies. You could opt to get eat these in their natural form, take them in supplement form, or a combination thereof.

Pertaining to heart health, some nutrients should be avoided. High levels of saturated fat, typically solid at room temperature, should be avoided. Sugar should also be avoided, as it tends to raise serum triglyceride levels and cholesterol levels. This is particularly the case with high fructose corn syrup found in sodas, candies, syrups, and other artificial foods like catsup and barbecue sauce. Opt for natural foods like lean meats, grains, fruits, and vegetables.

Until next time, do your heart (and physique) a favor by exercising and eating a healthy, balanced diet.

 

This entry was posted on Sunday, August 15th, 2004 at 12:00 am and is filed under Fitness. You can follow any responses to this entry through the RSS 2.0 feed. You can trackback from your own site.