Swimming-induced pulmonary oedema in triathletes: A narrative review of epidemiology, risk factors and prevention

Swimming-induced pulmonary oedema (SIPO) has predominantly been reported in swimmers. However, to date, no review has specifically explored the scientific literature concerning the occurrence and characteristics of SIPO in triathletes. Therefore, this review aims to summarize and discuss the current evidence on SIPO in the context of triathlon.

We conducted a narrative review to summarize the current scientific literature on SIPO in triathletes. A structured search of two major databases—PubMed and Scopus—was conducted using free-text terms related to SIPO and triathlon. The search included articles published up to January 2025, with no language restrictions. After removing duplicates and excluding animal or in vitro studies, as well as unrelated articles based on title and abstract screening, a total of 48 relevant publications were included for analysis.

The reports on SIPO in triathletes are mainly case reports or case studies on a single athlete or a small number (case series) of triathletes. Most reported cases involved middle-aged women (30–60 years) participating in IRONMAN^® 70.3 and IRONMAN^® triathlons. The prevalence of SIPO in triathletes is reported to be less than 1.5%. Risk factors for SIPO in triathletes are female sex, age over 50 years, hypertension, fish oil consumption, highly trained individuals, competitive exercise, wet suit compression, longer race distances (i.e. IRONMAN^® 70.3 or IRONMAN^®) and a cold (water) environment. The symptoms and outcome are similar to those observed in swimmers and other aquatic athletes.

In summary, the results regarding the prevalence, symptoms and risk factors of SIPO in triathletes are comparable to those in other aquatic athletes. SIPO occurs only in IRONMAN^® 70.3 and IRONMAN^® races, but has not been reported in the Olympic distance triathlon or triathlons longer than the IRONMAN^® race distance.