Not a doctor here, but I am someone who has years of experience with allergies, asthma, and chronic sinus infections. Please listen to your body, and not your mind. If you really feel OK, then go easy until you are done with your meds. I have exercised myself into bronchitis and pneumonia more than once because I didn't rest when it was just a sinus thing. Usually, I have a few days where I feel perfectly fine if I am just going about my daily activities, working, but if I ride, I feel weaker than s---. The trick is to get past this point, do some easy exercise like walking, and then start riding.