Group rides are very common. Listed above are only the more regular rides, and nothing on weekends. Check Strava club pages for Geoff's Bike & Ski (IC), Northtowne Cycling & Fitness (CR), and Sugar Bottom Bikes (NL).
Groups runs are common early mornings and weekends. For info, contact Corridor Running, Run319 (IC), and No Regrets Running (CR).
Swim practices for all ages happen daily. Contact Milky Way Masters in CR, the Iowa City Eels or IFLY​ in IC, or Iowa Masters for details.