Below 130, no reported case was free of symptoms
Across 56 field studies and 220 reported cases, not one below 130 millimoles per litre was symptom-free. The value itself did not track how severe a case was.
What the study found
Below 130, nobody in the case record was symptom-free
The blood number says something is wrong, not how wrong. Across 56 field studies and 220 reported cases of exercise-associated low blood sodium, not one case below 130 millimoles per litre was symptom-free, and yet the value itself did not track how severe a presentation was.
The caveat · Only the cases someone wrote up
These are the cases somebody wrote up. Severe and unusual presentations get published and mild ones do not, so this describes the case record rather than everyone it happened to. The search was a manual sweep of two databases, not a registered protocol. Women appear more often as a share of participants, not in greater numbers, a distinction the review itself insists on.