Even football players who havent experienced a concussion need time to recover from the head impacts they receive during the football season. A study published today in PLOS ONE reveals that the six month-long no-contact period that players are given between seasons isnt giving their brains enough time to recover. Researchers say this failure to recuperate could contribute to the kind of long-term cognitive disorders that some former-NFL players have sued the league over. To study the effect of non-concussive, repetitive head impacts, researchers put accelerometers in the helmets of 10 University of Rochester football players.