Published January 19, 2016 9:41am EST | Updated January 19, 2016 10:04am EST

Former Twitter CEO To Start Fitness Company, Become Venture Partner

Dick Costolo, the former chief executive of Twitter Inc. , said Tuesday that he would be co-founding a "software platform" centered on personal fitness. The platform will "go beyond measurement to motivate and drive improvement," Costolo tweeted. Additionally, Costolo tweeted that he will be joining venture capital firm Index Ventures as a venture partner. Costolo stepped down as Twitter CEO on July 1.