Filed under: Heart
You may have heard about the Body Mass Index (BMI), but do you really know what it is? BMI is an indicator of body fat for most adults—a screening tool for possible health problems. BMI is calculated using weight and height, and depending on the number, the result is categorized into underweight, normal weight, overweight, and obese. The higher the BMI, the higher the risk of certain diseases such as heart disease, high blood pressure, Type 2 diabetes, and certain cancers. The Centers for Disease Control and Prevention has an adult BMI calculator, child and teen BMI calculator, and information for interpreting the numbers.
Reports estimate that one of every four deaths is attributed to heart disease. Cardiorespiratory (aerobic) activities such as jogging, cycling, and swimming directly improve the function of the heart, which decreases the risk of coronary artery disease, high cholesterol, high blood pressure, stroke, and type II diabetes. Aerobic fitness is important enough that all active-duty service members must complete an aerobic fitness assessment, such as a maximal effort timed run, as part of their annual physical fitness test.
To delve a little deeper about the changes your heart, lungs, and blood vessels undergo when you improve your aerobic fitness, read on. One important change that occurs is that your heart’s “stroke volume”—the amount of blood the heart pumps out with each beat—increases. This comes from an increase in your heart’s strength and ability to hold a greater amount of blood. This in turn reduces your heart rate (HR) both at rest and at all levels of exercise. In fact, with consistent training, your resting HR could likely decrease as much as eight to10 beats per minute. That’s about 5 million fewer heartbeats in a year! Simply put, aerobic training means your heart has to do less work to get your job done.
Changes also occur to your blood and blood vessels with aerobic fitness. Your blood vessels increase in diameter and are better able to expand and constrict. This allows blood to move through your blood vessels with less resistance, reducing your blood pressure. And what happens to your blood? The levels of plasma (the liquid portion of the blood), red blood cells, and hemoglobin all increase, which means that your blood can carry more oxygen.
Altogether, the physiological changes mentioned here should make it easy to see why aerobic exercise is so important. If you want to learn more about how to get started improving your cardiorespiratory health through exercise, visit these Performance Strategies from HPRC.
Deployments, injuries, transitions—just a few of the many things that can interfere with your normal exercise routine. Too long a break and your cardiovascular—or aerobic—fitness may suffer. For optimal performance, however, getting your heart and lungs back in action is critical. If you’ve been away from your routine for a while, start slowly and gradually increase intensity and duration. Be patient and stick with a routine, even on days you don’t feel like it. Mix up your routine when you’re able with different types of aerobic exercise such as biking, running, swimming, and rowing. For help planning your comeback, check out HPRC’s Performance Strategies for Rebuilding Cardiovascular Fitness. If you’d like to learn more about aerobic conditioning specifically for the PRT/PFT, read part 1of our training series.
Are your high-school students gearing up to play a team sport? You might want to consider the pre-participation screening requirements and what’s on the horizon for future changes. The electrocardiogram—a test used to examine electrical impulses of the heart—has been used as a screening tool to identify cardiac problems. At the American Medical Society’s annual meeting, Dr. Francis O’Connor (Medical Director for the Consortium for Health and Military Performance, HPRC’s parent organization) recently presented an evaluation of recent recommendations from the European Society of Cardiology for physicians interpreting ECG test results of athletes. The accuracy of the interpretation is under scrutiny, as the results of ECGs can be tricky to interpret.
In the United States, athletes aren’t required to have an ECG screening prior to sports participation—but that might change in the future if it’s deemed that accurate readings of such screenings are reliable and might identify underlying heart abnormalities. For now, however, Dr. O’Connor noted, “identifying abnormal from normal is not as easy as it may seem.”
Individuals who have incorporated the recommendation of 10,000 steps a day into their lives have seen positive changes in their health, including weight loss, lower blood pressure, decreased risk for diabetes, lower cholesterol, and better psychological health. Many organizations, including the American Heart Association, recommend walking 10,000 steps—or approximately five miles—a day for optimal health. Having a goal of 10,000 steps will get you, your family, and friends moving more every day, which reduces health risks.
A pedometer is an easy way to start counting your steps! Turn it into a fun, inexpensive challenge for your family or colleagues—see who can get the most steps in a day or week. It might be harder than you think. Here are some tips from the American Heart Association to help you get to 10,000.
Solid fats are solid at room temperature, come mainly from animal products, and are high in saturated or trans fats. Examples are butter, milk fat, cream, stick margarine, shortening, and beef, chicken, and pork fat. Some saturated fats increase blood cholesterol levels in the body. Oils are liquid at room temperature, and come from many different plants, and are good sources of heart healthy unsaturated fats. Examples are olive oil, canola oil, safflower oil, corn oil, soybean oil, and peanut oil. Coconut oil, palm oil, and palm kernel oil are high in saturated fats and are considered solid fats. When using fats, replacing solid fats with unsaturated oils will provide essential nutrients to the diet and help lower blood cholesterol levels. Read about food preparation to promote health for more information.
Good cholesterol, or high-density lipoprotein (HDL), helps prevent fat and cholesterol from clogging your arteries. A higher HDL number (> 60 mg/dl of blood) is better. Low-density lipoprotein (LDL) is considered bad cholesterol. It carries cholesterol to your arteries and can cause them to become blocked. A lower LDL number (< 100 mg/dl) is better. High-LDL or low-HDL cholesterol levels are major risk factors for heart disease and stroke. Visit this American Hearth Association web page for more information.
Most people understand what it means to have high blood pressure, excess fat around the middle, a high cholesterol level, and the importance of addressing these health problems. What some may not realize is how serious the situation becomes when a person has been diagnosed with three or more such conditions in conjunction with other health issues.
This occurrence is called metabolic syndrome.
People who suffer from this combination of conditions (a reported one in four—50 million in the United States alone) have a dramatically increased risk for developing heart disease, type-2 diabetes, or a stroke. Individually, these symptoms pose a health risk, but identified together they raise the risk for cardiovascular disease.
Metabolic syndrome is characterized by a cluster of symptoms that include excess fat in the abdominal area (as measured by waist circumference), borderline or high blood pressure, high cholesterol that fosters plaque buildup in arteries, insulin resistance or glucose intolerance indicating the body can’t properly use insulin, raising blood sugar levels, and the presence of a protein in the blood, which can cause inflammation.
People with metabolic syndrome have at least three of the following risk factors:
- Excessive body fat around the waist
- Low levels of HDL ("good") cholesterol
- High levels of triglycerides (a type of blood fat)
- Elevated blood pressure
- Elevated glucose (blood sugar) levels after fasting
The complications of metabolic syndrome are serious and, if not addressed, can cause major health problems. If you are overweight and don't yet have these problems, keep in mind that the older you get, the more likely you are to develop them. Older adults can develop metabolic syndrome without being overweight, so it is important to get annual physical exams.
What can be done to prevent metabolic syndrome? If you are fall into the categories above or are overweight, one way to reduce your risk of metabolic syndrome is to incorporate healthy habits such as starting an exercise regimen. (But be sure to consult your doctor before starting a new exercise program, especially if you have not been active for a while.)
Diet is also key to reducing the risk of metabolic syndrome. By making small changes in your diet—such as decreasing the number of calories you take in per day; eating more fruits, vegetables, whole grain products, and low-fat meals, and avoiding fast/fried/fatty/oily foods—you can reduce your chances of developing metabolic syndrome.
If you would like to know more about metabolic syndrome, we recommend the following resources:
Monitor your heart rate to ensure that you are training in the appropriate range for your performance needs. This simple practice will help you track the way your body responds to training to effectively optimize your physical performance. The American Council on Exercise (ACE) has information on how to monitor your exercise intensity using your heart rate, as well as an online tool for calculating your target heart rate. A similar online calculator is available from the Army’s Hooah 4 Health website.
Heart disease is the number-one killer for both men and women. A well-balanced diet, along with regular exercise, can reduce the risk of heart disease. New heart disease guidelines were recently issued, with particular focus on illnesses that increase the risk of cardiovascular disease in women. For more information, read the news release and information about the new guidelines, which include information about the American Heart Association’s “Go Red for Women” campaign.