I am dealing with this very issue. Just getting over a bad cold (flu? I'm not sure) and trying to ride. Easy rides are OK but if I breathe hard I start coughing and it's hard to stop. That happened yesterday and was not fun. (Sucking cough drops while riding is not ideal and didn't help much anyway.) I still have some throat and chest congestion, it seems. Today I rode more easily, for almost an hour at moderate pace, without incident.