New research on the effects of repeated head injuries on high-school football players suggest the brain may not fully recover during the offseason and instead rewire around the injured areas. Researchers at Purdue University found that repeated head impacts have shown changes in brain chemistry and metabolism even in players who were not diagnosed with concussions. “We are finding that the more hits you take, the more you change your brain chemistry, the more you change your brain’s ability to move blood to the right locations,” said Eric Nauman, a professor of mechanical engineering, basic medical sciences, and biomedical engineering. The findings indicate that blows to the head could produce biochemical changes that could lead to neurological problems. The research team suggests implementing sensors into helmets to track hits to the head and monitor how well the helmet absorbs the blows.