Hoping to improve upon the remarkable feat of rushing for the second most yards in NFL history a year after tearing his ACL in the final week of 2011, Vikings running back Adrian Peterson announced Sunday that he has intentionally torn his ACL again and will undergo reconstructive knee surgery later this week. It worked last year on the left knee, so Im trying the other one this year, said Peterson, whose intense dedication to offseason recovery has earned him the reputation of rehab rat among his teammates. Its hard to get over that playoff loss, but immediately after, I got right back to work and tore my ACL. If I was just eight yards short of the record last year, Im thinking that rupturing my LCL and PCL this offseason should put me over the top. Peterson, who confirmed that he had found the best postseason regimen to stay on top of his game, announced plans for a new football camp where the Pro Bowl running back will show young players the best way to damage their knees by hacking away at their ligaments with scissors. 