Episode 192: SIPE/Dr. Jim Taylor

A brief synopsis of the episode's main discussions and takeaways as well as extended references

Author

Jeff Sankoff
March 13, 2026

Swimming Induced Pulmonary Edema gets a lot of attention because it is misunderstood and quite scary. How much do triathletes really need to worry about this though?

Table of Contents

SIPE-MMB looks at the evidence again and finds the fear likely outstrips the reality

Swimming-Induced Pulmonary Edema (SIPE): Myth vs. Reality in Triathlon

Swimming-induced pulmonary edema (SIPE) is a real but relatively uncommon condition that can occur during open-water swimming in triathletes. It involves the accumulation of fluid in the lungs during exertion, leading to symptoms such as sudden shortness of breath, cough, reduced exercise tolerance, chest tightness, and sometimes pink, frothy sputum. Oxygen levels may drop despite otherwise normal heart and lung function.

The physiologic mechanism is thought to involve a combination of factors common in triathlon swims: immersion in cold water, intense exertion, tight wetsuits, and the horizontal swimming position. Immersion shifts blood from the extremities into the chest, increasing pulmonary vascular pressures. In susceptible individuals, this pressure can cause fluid to leak from pulmonary capillaries into the air spaces of the lungs.

It is significantly more common in women than men and increasingly seen in older age groups because of the association with hypertension and other cardiac ailments that are more common with age. It is important to note that the presence of high blood pressure and heart issues are not a prerequisite for the development of this entity.

A common myth is that SIPE is simply anxiety or panic during the swim. While anxiety can produce shortness of breath, SIPE has objective physiologic findings such as oxygen desaturation and pulmonary crackles. Another myth is that it only affects unfit swimmers. In reality, it has been reported in highly trained endurance athletes, including experienced triathletes and military swimmers.

However, the risk is often overstated. SIPE remains uncommon relative to the number of open-water swimmers and most cases resolve with rest, warming, and removal from the water. Severe cases requiring hospitalization are rare. Risk factors may include hypertension, female sex, older age, cold water, tight wetsuits, and high swim intensity.

For triathletes, the practical takeaway is awareness rather than fear: recognize symptoms, stop swimming if severe breathlessness develops, and seek medical evaluation if SIPE is suspected. Early recognition improves safety while preserving the benefits of open-water racing.

Dr. Jim Taylor returns with advice for how to use mental performance to improve physical outcomes

About Jim according to Jim: Dr. Jim Taylor is considered one of the world’s leading authorities on the psychology of sport, performance, and parenting. He has consulted with athletes, businesspeople, military, educators, medical professionals, performing artists, and parents around the world.

Dr. Jim holds a Ph.D. in Psychology and has held faculty positions at universities around the U.S. He is the author of 18 books (translated into 10 languages) and is the editor of five textbooks. His blog posts have been read by more than 15 million people.

Dr. Jim is a former world-ranked alpine ski racer, a 2nd-degree black belt in karate, marathon runner, Ironman triathlete, and, since 2022, a 5x National Champion and 4x World Championship medalist age-group triathlete.

During our interview in this episode Dr. Taylor shares his expertise on the crucial role of mastering adversity, highlighting how athletes can cultivate mental strength through their experiences. The conversation emphasizes the importance of mental preparation and the necessity of rehearsing for potential race-day challenges. We explore five detrimental attitudes that can derail an athlete's performance: over-investment, perfectionism, fear of failure, fixation on results, and undue pressure. Dr. Taylor expertly articulates how these attitudes can weigh down an athlete, much like a heavy weight vest, and offers practical advice on fostering a mindset that embraces freedom and self-acceptance. The episode is interspersed with humor and relatable anecdotes, making it not only informative but also enjoyable for listeners seeking to enhance their mental performance in triathlons.

If you have ever wondered whether or not your mind could play a role in your physical performance and how to unlock the power of positive thinking to do so, this episode is for you.

Episode takeaways:

  • SIPE is real but not nearly as common as people fear.

  • SIPE increases with age and is more common in women

  • The likelihood of developing SIPE can be decreased by starting a race as calmly as possible with a lower degree of intensity and less forceful inhalations

  • Ditching that metaphorical weight vest really helps you unleash your inner athlete, so just go for it!

  • If you can stop worrying about the psychological baggage, you might actually perform better on race day.

  • Anxiety is like that annoying friend who shows up uninvited; just learn to deal with it while racing.

References used for the MMB

Pulmonary Edema

Cleveland Clinic

Key Points:

  • Pulmonary edema, which can be both acute and chronic, is defined as the buildup of fluid in the lungs

  • This condition, which causes shortness of breath, foam/mucus coughing up, tightness in the chest, and breathing difficulties, can be fatal, requiring immediate attention and management

  • There are multiple pulmonary edema conditions, including high altitude pulmonary edema (HAPE) and immersion or swimming-induced pulmonary edema (SIPE)

  • SIPE is a lung injury caused by the bursting of capillaries in the lung as a result of increased pressure in the blood vessels due to excess blood flow from the legs/abdomen

  • The fluid that leaks fills the air sacs

Swimming-Induced Pulmonary Edema

Key Points:

  • Long-distance and cold water swimmers are at a higher risk of experiencing abnormal leakage of fluid in the lungs, a condition known as SIPE

  • Cardiac conditions, high blood pressure, increased levels of stress, underwater exertion, excessive pre-hydration prior to immersion, consumption of antiplatelet agents, and use of devices like snorkels can increase the risks of developing SIPE

  • If the condition occurs, it is important to help reverse the hydrostatic effects of immersion and negative pressure by removing the individual from water, sitting up, and warming the body.

Swimming-Induced Pulmonary Edema

Lili Barouch, 2022

Key Points:

  • This paper is a case report of SIPE

  • SIPE is an underreported condition that can be a leading cause of emergency and death associated with triathlon and open-water swimming events

  • This condition was first described in the 80s among scuba divers and swimmers

  • Although it has previously been reported as rare among healthy athletes, with reports noting an incidence of 1.1-1.8% among triathletes and combat swimmers

  • However, its prevalence is higher than previously thought

  • While its pathophysiology is not fully understood, increased central blood pooling can occur when immersed in water in the supine position

  • This can be aggravated in cold temperatures and/or wetsuit compression in the legs 

  • The pooling of blood can increase pulmonary capillary pressure, which can overwhelm the alveolar pressure to cause pulmonary edema

  • These effects are exacerbated by conditions like hypertension

  • This paper notes that the importance of considering risk factors such as age 50+, female sex, and underlying cardiac conditions, such as hypertrophy and hypertension, along with situational factors like temperature and wetsuits

  • This condition has a high recurrence rate of 13-22%, avoiding cold water and tight wetsuits, warming up well in the water, and consuming sildenafil before activity can mitigate the risk of SIPE in cold waters

The Immersion-Induced Pulmonary Edema in Swimming and Diving

Koch et al., 2024

Key Points:

  • This paper is a clinical review summarizing the underlying pathophysiologies, clinical symptoms, outcomes, and prognosis of IPE

  • Staying underwater can cause acute immersion-induced pulmonary edema (IPE), especially in swimming (SIPE) and diving (DIPE)

  • The following pathophysiological processes: fluid shift, severe breathing, strenuous exercise, ambient cold, and aggravating cardiac pathologies are known to induce IPE

  • In water, buoyancy causes a loss of hydrostatic pressure in your legs, leading to a 500-700ml extra flow in blood towards the center of the body, which increases your mean arterial and central venous pressure

  • Greater volume of blood returns to the heart, leading to secretion of ANP and activation of the Frank-Starling mechanism

    • ANP is a hormone released by the heart when increased blood volume causes the heart chamber (atria) to expand

    • This hormone causes your body to lower blood volume and pressure through salt secretion, urine production, and vasodilation

    • The Frank-Starling mechanism is the adjustment of heart contraction strength in response to increased blood flow into the ventricles

  • Heart rate decreases simultaneously, which can cause bradyarrythmias

  • Fluid can leak into the lungs and fill the alveoli when larger amounts of blood cannot be handled by the heart, causing the lungs to experience enhanced capillary pressure

  • Powerful inhalation is also induced during swimming and diving exercises

  • This suction of air creates a strong negative pressure in the lungs, which can pull fluids out of the capillaries and into the alveoli

Swimming-Induced Pulmonary Edema: A Scoping Review and Analysis of Epidemiology, Pathophysiology, Diagnostics, Management, and Implications for Resource-Limited Care of Patients

Steins et al., 2026

Key Points:

  • I did not have full access to this paper

  • This paper conducted a review of the current understanding of SIPE, which is a medical condition that is often misdiagnosed or overlooked

  • It is characterized by acute dyspnea, cough, and hemoptysis during or following cold-water exercise

  • Pathophysiology of this condition involves increased pulmonary capillary pressure from blood pooling, cold-induced vasoconstriction, and exercise-induced cardiac output

  • Lung ultrasound is a promising, rapid, and noninvasive diagnostic tool for this condition

  • Rapid removal from water, oxygen therapy, and application of positive airway pressure helped to manage and/or reverse this condition, which has a risk of being fatal when left unmanaged

  • Preventative measures continue to be studied

Methods: Studies, case reports, and clinical guidelines on SIPE were reviewed and analyzed to extract data. PRISMA extension used to scope literature on PubMed. 

Swimming-Induced Pulmonary Edema: Diagnostic Criteria Validated by Lung Ultrasound

Hardstedt et al., 2020

Key Points:

  • The goal of this study was to identify the diagnostic criteria of SIPE during Sweden’s Vansbrosimningen open water swimming event.

  • Symptoms of SIPE include cough, dyspnea, increased sputum, and/or hemoptysis.

  • By analyzing the SpO2 and lung auscultation results, this study presented a diagnostic criteria of SIPE in swimmers with an acute onset of cough and dyspnea during or after swimming in an open water event.

  • This study presented a novel finding that pulmonary edema is focally distributed in the anterior parts of the lung, and is sometimes unilateral, contributing to a unique dataset of an underreported condition

Methods: Cross-sectional study. 17,904 participants across 1k, 1.5k, and 3k races in the 2028 and 2019 Vansbrosimningen event. 160 of 166 swimmers who sought medical attention for acute respiratory symptoms were included in the study. Pulmonary edema confirmed on-site by lung ultrasound. Swimmer’s age 18+ yo. 

Results: Pulmonary edema confirmed in 64% of patients (102 swimmers). Prephiral oxygen saturation <95% identified as a strong independent diagnostic factor. Crackles on lung auscultation, especially anterior to chest, identified 88% patients. Peripheral oxygen saturation =<95% or auscultation findings of crackles identified pulmonary edema with 97% sensitivity and 86% specificity. 98% specificity and 99% predictive value for lung ultrasound-verified pulmonary edema incidents if patients presented with both oxygen saturation =<95% and auscultation of crackles.

Swimming-Induced Pulmonary Edema

Moon, 2023

Key Points:

  • This paper provided an analysis of the long-term follow-up on swimmers who experienced SIPE during the Vansbrosimningen Swedish open water event.

  • Similar to other papers published in recent years, this paper reports that the prevalence of SIPE in physically fit individuals is higher than previously reported numbers, with a 5% incidence among US Naval special warfare trainees and 27% incidence among Israel Defense Force swimmers during high exertion swimming.

  • According to a previous analysis of 11,000 participants in Sweden’s 1k and 3k river open-water swimming event, the prevalence of SIPE increased depending on the age and sex of participants

  • The oldest age group of 61yo+ had a 12.74 times higher risk relative to the youngest 18-30yo group.

  • 136 cases of SIPE were identified through physician diagnoses, and an additional 29 cases were identified through a retrospective review of lung ultrasounds for a total of 169 follow-up cases.

  • Women were 8.59 times more likely to experience this condition relative to men.

  • The hemodynamic cause of SIPE was confirmed by studies of SIPE-susceptible individuals during submersed exercise, who, compared with control participants, had higher pulmonary artery and pulmonary artery wedge pressures

  • This article noted that a study by Sebreros et al. (2023) previously noted that respiratory pathogens are commonly found in military trainee SIPE cases, suggesting that an infectious process may predispose pulmonary edema by reducing alveolar capillary membrane permeability

  • Furthermore, the authors mention that asthma treatment may attenuate the risk of SIPE, drawing on the possibility that abnormally high airway resistance causes greater negative intrathoracic pressure during inspiration, which may influence the intrathoracic blood transposition and predispose individuals to pulmonary edema

SIPE in Recreational Swimmers: Potential Mechanisms for Sex and Age Difference in Prevalence

Lindholm et al., 2024

Section by Hardstedt as part of the Proceedings of Barotrauma and SIPE in Freediving Workshop 

Key Points:

  • Men have historically dominated the literature related to IPE and SIPE

  • Recent mixed-sex cohort studies reveal a higher incidence in women for both IPE and SIPE

  • A cohort study og 47,000 recreational swimmers during Sweden’s Vansbrosimnigen showed that roughly 90% of the 211 SIPE cases were in women despite equal participant gender distribution

  • This article reports that early lung development differs between sexes 

  • Even when matched for height, women have smaller lung volumes, fewer alveoli, and smaller central airways

  • The luminal areas are 15-30% smaller in women, even when matched for the difference in lung volume

  • Higher incidence in women may be attributed to differences in cardiopulmonary anatomy and physiology

Not a subscriber to the podcast? Click here!

Support the podcast: TriDoc Podcast Patreon site

Need an endurance coach? TriDoc Coaching

Reply

or to participate.