Personal experiment: a smart contract that penalizes me if I skip workouts

Hi r/ethereum,

I’ve been running a personal experiment called FitVow.

The idea is simple: I stake real ETH into a smart contract, commit to weekly physical activity goals, and let the contract enforce the rules without a trusted referee.

Each week, an Android app reads physical activity data from my smartwatch and publishes it on-chain (e.g. runs, workouts and etc). The contract uses that data to decide whether that week’s goals were met.

If a week fails:

• that week creates an enforceable fine (paid out from the stake)
• enforcement is permissionless (anyone can trigger it)
• the fine is split between the enforcer (caller) and a charity wallet (Giveth)

At the end of the challenge, I’m allowed to withdraw whatever remains of the stake after any fines.

There’s no backend deciding outcomes and no admin override. Once deployed, the rules are the rules.

This is not a product — just an experiment exploring whether Ethereum is a good tool for credible self-commitment outside of DeFi.

Live dashboard (reads directly from on-chain data):
https://fitvow.pedroaugusto.dev/

Technical write-up (architecture + security assumptions):
https://pedrooaugusto.github.io/blog/posts/making-missed-workouts-cost-money-with-smart-contracts/

I’d love feedback — especially on whether this feels like a reasonable use of Ethereum, and what you’d poke holes in.