Former Twitter CEO Dick Costolo announced on Tuesday that he’s taking on two new jobs, the most notable of which is the founder of a new personal fitness startup, while the other is a venture partner for Index Ventures. Amusingly enough, he made the announcement through his Twitter account, and went into a little bit of detail about his new startup, saying that it’ll focus more on motivating people to exercise than just tracking their vitals. He didn’t reveal anything else about the company, and we still don’t even know what it’s called, but at least we have an idea of what he’s up to.