Hi Daniel, thank you for your help.
Yes, those APIs were the first thing I looked at and they may figure in the final implementation. There is a wide range of health and safety risks that we want to detect - for example, poisoning, heart attack, severe pain, stress etc all of which we are developing algorithms. These more general sports and nutrition APIs do not cover these more specialised use cases of course, but I will investigate more - a great suggestion.
The device will need to support an indoor location and tracking algorithm on board too - thus contributing to finding out whether we can develop a native Android mobile app on the Outsystems platform, functioning on a display-less device. As an aside, it also appears that I will have to use Cordova to access the sensors. The final option I guess would be to develop a full Android app without Outsystems, but then face losing all the associated benefits.
Thanks again
Marc