Hey - if you're interested in prototyping with real data, we've built a platform for stuff like this -- Fulcra Context (https://www.fulcradynamics.com/). We have an iOS app that collects Apple Health data, and you can then share it with a coach/trainer/doctor/etc.

We have a REST API with python client lib (https://fulcradynamics.github.io/developer-docs/), an MCP server (https://fulcradynamics.github.io/developer-docs/mcp-server/), and did some experiments with ChatGPT actions as well (https://www.fulcradynamics.com/chatgpt).

It doesn't have the simplicity of a plain export to duckdb/sqlite, but it definitely helps solve a lot of the sharing/collaboration problems.