It really depends on where you define the threshold for "symptomatic". If reduced lung perforce is a symptom, then it's tautological to say "no damage in the as

It really depends on where you define the threshold for "symptomatic". If reduced lung perforce is a symptom, then it's tautological to say "no damage in the asymptomatic". If your threshold is "feeling bad enough to call emergency services", then there is plenty of room for massive performance loss without ever coming close to that threshold. People who don't routinely measure athletic performance wouldn't even notice losing the equivalent of an entire lung lobe as long as the loss doesn't come in a very short time.