Sport News : Sex, age may affect athletes' concussion recovery

Meanwhile, high school athletes fared worse on memory tests than college players, and typically took longer to improve.

For parents, coaches and athletes, the key message is to have patience with concussion recovery, said lead researcher Tracey Covassin, an assistant professor at Michigan State University in East Lansing.

"It's going to take time for your child to fully recover, so don't rush them back into the sport," she said, adding that extra time may be in order for female athletes and high schoolers.

The stu dy covered 222 high school and college athletes who suffered a concussion over two years, including players in football, soccer and volleyball.

Covassin's team gave them standard tests of memory and other mental skills, as well as balance, over their first two weeks after they suffered concussions.

Overall, female athletes complained of more symptoms than their male counterparts - an average of 14 symptoms, versus 10. Concussion symptoms include problems like headache, dizziness, nausea, ringing in the ear, fatigue and confusion.

Female athletes also had lower scores on visual memory tests, though male and female players alike gradually improved over the two weeks.

High school athletes, meanwhile, performed worse on memory tests than their college counterparts and improved more slowly. After one week they were still lagging behin d older athletes.

And among male athletes, high schoolers also had more problems when researchers tested their balancing skills.

Younger athletes likely need more recovery time because the teenage brain is still developing, Covassin said. It's also smaller, which means it can be more easily "knocked around" within the skull if a young athlete takes a hit.

It's not clear why female athletes may fare worse, but there is research suggesting that differences in brain structure are at work.

And young athletes seem to be sustaining more concussions than in the past. A study found that in 2008, there were five concussions for every 10,000 U.S. high school athletes who hit the playing field. That was up from just one per 10,000 a decade earlier.

There are more people playing contact sports, and yo ung athletes are training more aggressively at an early age. Doctors are also becoming more vigilant about diagnosing concussions, experts said.