Athletics are known to be potentially dangerous. But a study released by the Purdue Neurotrauma Group has discovered that the head trauma experienced by high school football players and women’s soccer players is much more widespread than was originally known.

According to Reuters, the study found that over a seven year period, the study found that more than half of the players studied showed signs of altered neurological function, and major changes to the wiring and biochemistry of the brain.

The study was conducted by putting sensors on the athletes to record impact forces while also doing brain scans and cognitive tests to track neurological function over the course of the trial. The results showed that hits that have previously been thought of as less dangerous, actually pose more of a risk because they go unnoticed and occur more frequently. This ends up resulting in more damage long-term to the neurological function of the athletes.

The study also found similar results in women’s soccer. In both football and soccer, some of the negative effects will go away during the offseason, but are still lingering, as athletes get ready to start competing in their sport again.

http://www.reuters.com/article/2015/10/07/us-usa-foodball-head-trauma-idUSKCN0S12AT20151007