Pick up basketball. If I were a professional athlete, other than an NBA player, I would just as soon take my chances with baggy pants in an uptight suburban shopping mall. At least the latter isn't a potential career ender, unless it exposes some unpaid bills. Former Dolphins QB Chad Pennington, a free agent, tore his ACL playing America's deadliest game, likely ending his career. More importantly, the incident serves as an ominous reminder of the risk to players working out (or recreating too, I guess) during the offseason...players like St. Louis Rams QB Sam Bradford who has promised to workout with his wide receivers during the lockout.
Players injured while working out on their own can be placed on the non-football injury list when and if the NFL and players get the lockout lifted. Under those circumstances players would forfeit their 2011 salaries. Teams aren't liable for those injuries either.
Those workouts aren't as innocuous as they seem. Another big risk of an extended lockout.