Concussions are unfortunately fairly commonly seen, especially after sport related injuries. There is agreement that contact sports should be avoided and the length of time recommended varies widely.
What about non contact sports such as biking,running and swimming? Well, a recent study showed that exercising does not by itself make the symptoms of a concussion worse. These symptoms include headache, confusion, nausea and dizziness.
In fact one study shows that for children with concussions early onset of exercise is actually a good thing. Kids who started non contact sports early on did better than those who held off on all forms of exercise.
Certainly, if your symptoms become worse after exercising, then hold off. And for sure avoid contact sports such as football and wrestling.
The real question is for how long you should hold off on contact sports. In part, this depends on how bad your concussion was, whether or not there were recent concussions and how great the risk is of another concussion.
For kids with minor concussions, I think it is reasonable to lay off of any contact sports for at least one week. There are more and more studies coming out about concussions so stay tuned!