The following are useful tables for personal trainers and those interested in tracking health parameters. A description is given of risk category, body mass index, body fat percentage, waist circumference, hip circumference, waist-to-hip ratio, and blood pressure, along with how these measurements are useful in tracking health and fitness goals.
The risk category table guides those new to exercise in deciding if it is necessary to see a physician before beginning an exercise regimen. It is probable that low risk individuals will be okay starting a new exercise program and will adjust to the intensity of the program without serious complication. Moderate to high risk individuals may have serious complications if they begin a moderate to rigorous exercise program and it is recommended that they consult with a physician before beginning. (CAD) refers to cardiovascular disease. The following guide can assist in determining one’s CAD risk factors: ACSM CAD Risk Factor Thresholds.
Body Mass Index (BMI)
Body mass index, or BMI, refers to a number calculated based on an individual’s weight and height. It is useful in determining if an individual is in a weight category that may lead to health complications. You can calculate your BMI here.
Body Fat Percentage
An individual’s body fat percentage is the total mass of fat divided by total body mass. It is often used to more accurately access muscle gain and fat loss when an individual has weight loss goals. We often associate weight loss with exercise, but exercise assists in depleting fat stores while also increasing muscle mass. Therefore, measuring the percentage of body fat gives a better indication of actual fitness results as opposed to only measuring total weight loss because it considers both fat loss and the added muscle mass associated with strength training.
Body fat percentage is most commonly measured using a bioelectrical impedance device. You simply hold this device out in front of you for a few seconds after inputting your age, height, and weight; it sends a mild electrical impulse throughout your body and measures the resistance to the current. The idea is that the volume of fat-free tissue in the body is proportional to the body’s electrical conductivity. Fat is a poor electrical conductor as it contains little water, lean tissue contains mostly water and electrolytes and is a good electrical conductor; therefore, fat provides impedance to the electrical current. The device is pretty accurate although it is programmed based on a few assumptions about hydration levels and water content. To get the most accurate reading, do not eat or drink within 4 hours of the test, do not exercise within 12 hours of the test, urinate (or void) completely within 30 minutes of the test, and do not consume alcohol within 48 hours of the test. Most importantly, take the measurement under the same conditions each month if possible.
Calipers can also be used to take skinfold measurements; a formula is then used to determine the body fat percentage. This is just about the same accuracy as the bioelectrical impedance analyzer except it takes a little more time and requires a lot more skill.
Very accurate techniques include hydrodensitometry and plethysmography; they are a little excessive for the average individual looking to track their fitness results over time.
Waist Circumference Risk
Waist circumference can be measured with a flexible, inelastic tape measure. Here is a helpful video for measuring the circumference of your waist: How to Measure Your Waist Circumference.
Excessive abdominal fat provides an increased risk of hypertension, metabolic syndrome, type 2 diabetes, dyslipidemia, coronary artery disease, and premature death.
Waist-to-Hip Ratio (WHR) for High Health Risk
Hip circumference can be measured in the same fashion as the hips: Measuring Hip Girth. The waist-to-hip ratio is simply found with the following formula: (waist measurement/hip measurement). It is a simple method for determining body fat distribution and is another tool used to indicate the probability of developing a serious health condition.
Blood pressure can be measured most easily with a digital blood pressure monitor. The directions will come with the monitor :-). Or, just go to a pharmacy or write it down each time you visit the doctor. Its best to take 5 or more minutes to relax before the reading.
Each of these measurements are tools which indicate the current health and fitness levels of an individual. The idea of beginning a consistent exercise program is to normalize these levels. They are simply tools, and may or may not provide insight into the overall health of an individual. A physician and qualified trainer can help individuals with aspiring health and fitness goals use these tools and tables most effectively. Progress can be marked monthly, but noticeable change may take months to occur after adopting a consistent exercise program.