The user’s guide for your software should have a brief description of each of the equation sets, and why it was created. (It may be in the FAQ section in the back.)
In general, most people tend to use the “NHANES-III” equation set. The equations for Fat and Fat-Free Mass, and Total Body Water were developed as part of the Fels Longitudinal Study, which collected information about a large cross-section of the American population. A second study was done which showed how the equations performed on data collected in the NHANES-III survey, which also included a large cross-section of the American population. As a result, it tends to provide good estimates for body composition for individuals with relatively nondescript body types — that is, they resemble a “typical American of their sex and (approximate) age.”
However, for people who do not resemble the general population, the accuracy of these equations will tend to degrade. For example:
For people who are very thin or very skinny or who, when you look at them, you can say “Just by looking at you, I can tell that you work out on a very regular basis,” the NHANES-III set will tend to over-estimate body fat. That is, they may estimate body fat too high. For these people, we generally recommend the “Athletic” equation set.
On the other end of the spectrum, for people who are very obese, the NHANES-III equations will tend to under-estimate fat. For these people, the “Obese” equation set will likely provide a more accurate estimate.
To create a formatted report, go to the Test Results and touch the “Sharing” icon at the top of the screen, and press the “Generate Report” button. If you are satisfied with the way the report looks, tap the Sharing icon again.
Press the “Email PDF” button to send the report to someone as an attachment to an email.
Or, if you have an AirPrint-enabled printer (or other third-party software to enable printing from the iPad) use the “Print PDF” button to send the report to the printer.
Not in this initial release. Finding a way to make that work that was easy to use proved to not be a simple task. So we decided to release the app without that functionality, and release an update in iTunes when we get it figured out.
Can I access the same database from multiple iPads with the RJL app, or share it with BC on my desktop computer?
Not in this initial release. Without asking you to trust your body composition data to some third-party cloud service, finding a way to make that work that was easy to use proved to not be a simple task. So we decided to release the app without that functionality, and release an update in iTunes when we get it figured out.