BC3 Frequently Asked Questions

  1. How can I achieve the most accurate reading?
    Answer: For the most consistent and accurate readings, users should do the following when scanning body composition:
    • Stand with feet shoulder-width apart.
    • Grasp the BC3 firmly without squeezing hard (i.e., light "golf club" grip, no white knuckles). Hands and thumbs should be touching the metal bars. Thumbs should be pointing up.
    • The user's back should be straight and arms extended forward with elbows locked, but not hyperextended.
    • Make sure hands and fingers are not touching.
    • Hold the BC3 until the multicolored bar on the computer screen extends completely to the right.
    • Stand in the same position during each scan.
  2. What is essential fat?
    Answer: This is the amount of fat you need to be healthy and for your body to function properly. Having less than this amount of fat can be dangerous to your health. Generally speaking, a female's essential fat is 10-12% and a male's is 2-4%. You can use this chart as a general guideline:
  3. Can I sit down and hold the BC3?
    Answer: It's best to stand, but the most important thing is to be consistent in your position every time you take a reading, as results may vary slightly from standing to seated positions.
  4. How does the BC3 Body Composition Analyzer work?
    Answer: The BC3 Body Composition Analyzer uses bio-impedance technology, a state-of-the art, very accurate method of determining body mass. The device sends a mild electrical current through your body, measuring both the strength and speed of the return current. From these readings, the software calculates your body mass. The device is safe, but you should not use it if you are pregnant or have an implanted electrical medical device such as a pacemaker.
  5. Will it hurt?
    Answer: No, the electrical current generated is extremely low power.
  6. How does it know how much body fat/water I have?
    Answer: The device sends a small number of electrical currents into your body. Because certain body tissues conduct electricity better than others, the device can measure the current leaving your body and estimate your body composition, based on very sophisticated algorithms developed over years of clinical testing.
  7. How often should I test my body fat?
    Answer: It is not a good idea to put much emphasis on back-to-back readings whether 1 day apart or 1 week apart. Looking for trends over a series of readings will give you much more help in reaching and maintaining your desired body composition.
  8. How accurate is this device?
    Answer: Based on recent studies the accuracy of scan results show no appreciable difference between hydrostatic weighing and DXA scans.
  9. If I just ate, drank, or worked out will it affect my results?
    Answer: In most instances it won't, but we recommend you adopt a routine of capturing your reading in the morning before you begin your daily activity.
  10. Why do other bio-impedance devices tell me I have really high body fat?
    Answer: With normal bio-impedance devices, your hydration status can affect the results. For example, the devices see that you don't have much body water, and since your body water is all contained within your lean body mass, the devices think you do not have very much lean tissue. And if you don't have very much lean tissue, the devices assume the rest must be fat.

Body Composition Frequently Asked Questions

  1. What is lean body mass?
    Answer: Lean body mass is everything in your body except body fat - muscles, bones, organs, blood, etc.
  2. Is there any way to know your true body composition for sure?
    Answer: The only way to measure your body composition with 100% accuracy is to do an autopsy. Even a full body scan is not exact. Once you introduce an estimation into the mix via an equation (which all methods do) it's impossible to be exact. The trick is to eliminate as much variability and error as possible given the tool you're using. Stayhealthy has spent over a decade refining its measurement algorithms to be as accurate as possible.
  3. Why do women have more body fat?
    Answer: In addition to the basic essential fat we all need, women have an additional 9-12% fat primarily to provide protection for child-bearing and to account for additional breast tissue.
  4. What should my lean body mass be?
    Answer: Your lean body mass is just the inverse of your body fat percentage, or in other words, everything but fat is lean body mass. By decreasing body fat and increasing lean body mass simultaneously, you improve the ratio, which is what you want to do, as long as you don't go below your essential body fat percentage. You can use this chart as a general guideline:
  5. How is the Stayhealthy Hydration Index measured?

    This question has been investigated through many research projects and clinical trials. At Stayhealthy we reviewed a number of published works on the subject and even conducted our own clinical trial. We have developed the Stayhealthy Hydration Index (SHI), which calculates on an individual basis, your specific hydration status based on broad population averages and studies.

    On the graph showing your hydration results is a line marked with zero. This represents the threshold for acceptable hydration, and should be considered the minimum level of hydration your body needs. A measurement above zero is desirable.

    Each person's zero point is calculated by determining the hydration of their lean mass (everything except fat), plus the water contained in their body fat. Just as physical makeup varies from person to person, so does the zero point.

    For more information on hydration, please refer to this Technical Health Bulletin (PDF).

RT3 and Research Activity Monitoring Frequently Asked Questions

  1. What are the minimum system requirements for the RT3?


    • English version of Windows 2000/XP
    • .NET Framework 2.0
    • 233MHz processor
    • 64MB RAM
    • 10MB free hard drive space
    • CD-ROM drive
    • 256 color video card and monitor
    • Mouse
    • Keyboard
    • One available USB 1.0 port
  2. What is the orientation of X. Y, and Z axes?

    Answer: When wearing the RT3 at one's side:

    • X is up and down.
    • Y is forward and back.
    • Z is side to side.
  3. How do I view the graphs I saw when I downloaded my data?
    Answer: The RT3 Assist software provides only the functionality to upload user profiles and download data. The graph shown briefly after download is displayed as a quick confirmation of the data integrity. You may use any third party data analysis or spread sheet program to open the saved data file.
  4. Why can't I establish communication with the RT3?
    Answer: This can mean that the batteries in the RT3 Dock are weak or dead. Replace the batteries with new alkaline batteries and try again.
  5. Why is my downloaded data not formatted correctly?

    Answer: This may happen if you are using a regional Windows setting other than US. This occurs if a comma (,) is being used instead of a period (.) as a decimal point. To correct this:

    • Click Start > Setting > Control Panel
    • Double Click Regional Settings
    • Click the Numbers tab at the top of the window
    • Change the Decimal symbol to a period using the drop down menu
    • Click OK

    Any data you download after making this change will be formatted correctly.

  6. I'm doing a study involving children. Will the RT3 work well for my age group?
    Answer: The RT3 is not able to accurately calculate metabolic calorie burn in children under the age of 10, however it can be used as an activity monitor.

Health Center Kiosk Frequently Asked Questions

  1. What is the proper method for taking a Body Content Reading?
    Answer: Sit comfortably with both feet on the floor. Lean forward from the waist placing, elbows locked straight, and the palm of your hands flat on the electrodes on the kiosk. The key to accurate readings is consistent placement at every test.
  2. What is the proper way to take a Blood Pressure reading?
    Answer: Insert your arm through the Blood Pressure cuff till your elbow is past the cuff and resting on the platform inside the cuff sleeve. The cuff should be resting on the upper part of your arm, above the elbow. Once fully inflated and a reading has been achieved the cuff will deflate. This can take anywhere from 30 seconds to one minute. The cuff will not hurt or damage your arm, please do not attempt to withdraw your arm until fully deflated.
  3. Why does my blood pressure change during the day?
    Answer: From the American Heart Association, "Readings can vary throughout the day and can be temporarily influenced by factors such as emotions, diet and medication. A record of readings taken over time can provide you and your healthcare provider a clearer picture of your blood pressure. It can be like a time-lapse picture or movie, providing information on what is happening with your blood pressure over time."
  4. How do I measure my weight?
    Answer: A scale is built into the seat. To ensure an accurate reading, follow the instructions on the screen. Ensure that both feet are entirely off the floor and resting on the lip or arm provided, and no part of your body is touching the floor. This ensures your full weight is on the scale. Once you have lifted your heels onto the lip or step, take the reading as instructed on the screen.