How soon after a mono diagnosis should an athlete return to activities?

It depends on the type of activity and how mono has affected the athlete. For contact sports, it is typically recommended to wait four weeks after the diagnosis or onset of symptoms before resuming. For light exercise such as jogging or biking, this can be done two weeks after the diagnosis or onset of symptoms.
 
Transcript: "That is a great question. It depends about the type of activity. For one thing, if it's a contact sport versus a non-contact sport, that makes a difference. And the other thing is mono affects everyone differently. With one person, it could just be a low grade fever and a sore throat for a couple of days, and then they feel fine. With others, they could be in bed with a high fever, a really swollen sore throat, hard to eat, and extremely fatigued. So it really varies depending on how the model has affected that athlete. In terms of resuming light exercise, once the athlete doesn't have any fever, is not taking any medication to help with keeping the fever down or to help with sore muscles, and their baseline, they're back to normal. They don't feel tired, their sleep pattern is normal. Then they can resume some light exercise, like jogging, bike riding, and see how they feel. If they do OK from there, then they can gradually progress their activity. But keep in mind is what's really affected is the spleen enlarges during mono. And the architecture of the spleen gets inflamed. That virus can affect the spleen as well, and there's a risk of rupture. If it's put under too much pressure with exercise and/or there's a blow to the abdomen, and the spleen is big, the spleen normally is covered by the ribs. But when the spleen enlarges, it'll get larger than the rib cage. And that increases its likelihood of getting injured during a contact sport. So the rule of thumb is four weeks. No contact sports until four weeks after the diagnosis or the onset of symptoms of mono. You can sometimes fudge that a little bit, and it can't be early as three weeks. But that's a decision that's made by the athlete's physician and a sports medicine physician that really understands the athlete's demands and their sport, and can determine what the risk is of the athlete returning back to sport. So rule of thumb, four weeks for contact sport. But if they're feeling good, they can start some light exercise at around two weeks. I hope that helps. If you have any more questions, please ask or go see your physician. Take care."