In both groups , those with more fights or years of fighting under their belt were more likely to have lower brain volume in three areas , as diagnosed with an MRI .
Researchers split the athletes into two groups based upon the years of fighting .
In both groups , those with more fights or years of fighting under Researchers ' belt were more likely to have lower brain volume in three areas , as diagnosed with an MRI .
Researchers split the athletes into two groups based upon the years of fighting .