Making Sense of Fitness Data

When the founders of this website, Paul Balsom and Göran Fransson, started to work together more than 30 years ago, the devices to measure exercise and “fitness” were alot fewer than today. Modern technology such as GPS, Bluetooth and accelerometers were not available, or at least not in a form or price that made them interesting. Within the last year the market has basically been flooded with interesting devices, and many people now use them and collect data sometimes even 7/24.

We have chosen to use a fairly unscientific term as “fitness” to present data and analysis relating to exercise, and the body’s response to it. As far as we know, there is no scientific definition of it, and it does not have an SI unit connected to it, but it has a fairly undisputed positive ring to it. Some people might feel that too much training or strength can be unhealthy or dangerous, but we think most people feel positive about the idea of “feeling fit”.

Being scientists, we strive to make it a little more scientific as well. When we started to work together, Paul was getting his PhD at GIH/KI in Stockholm, where some of most fundamental research on a persons capacity was done, yet another 40 years earlier. P-O Åstrand and Irma Åstrand published papers on how to test a persons ability to exercise with a simple test that only required a ergonometer (bike with known resistance) and a way to measure the heart rate. The result was presented in terms of the maximum oxygen intake a person has per kilogram of body mass. Still today, this is probably the most common “unit” used to describe a persons “exercise capacity”.