I think I'm late to the party, but I'm working on something in this area — accountability groups. Right now the focus is developers, but we will eventually expand it. The way it works:

- you pay for a spot in a group (limit 6 per group)

- groups run 30 days using Telegram

- you have to post 1 update per day (i.e. "I went to the gym")

- for each day you don't post, you get charged a penalty fee

We've already run a few for things like building side projects and it's worked really well. I think it could really help with something like exercising or working out too.

You can check it out here: https://dip.chat