Exercise-Induced Pulmonary Edema

For years my lungs have felt "waterlogged" after certain long workouts. By this I mean that when I breathe in deeply I feel a pain in my lungs of varying intensity and sharpness. Sometimes a dull but obvious pain. Sometimes a very sharp and breath-stopping pain. The pain usually starts when my lungs are only about half full. I always equated the feeling to one I had after a surgery in high school. They said that I'd have fluid in my lungs and told me to breathe in deeply every 30 minutes for a couple days.

For me, there seem to be some common factors that trigger the feeling. It's almost always associated with very long workouts. In my first two Ironman seasons this meant long runs or bikes of 3+ hours. By my third season that alone wouldn't trigger anything. It would take a 6+ hour bike on a hot day. Or a 6+ hour bike with a very hard last hour. Or a 6+ hour bike plus a hard run. Heat over 86 degrees seems to be a hurdle point. Heart rate over 145 for 4+ hours seems to be a trigger point.

Since I had experienced the sensation before I never really thought too much about it. It was usually gone within a day or so. But last season I spectacularly blew myself up (self-detonated or nuked, in Gordo terminology) in the middle portion of the season. And the waterlogged feeling of pain in my lungs stuck with me for many weeks despite easier workouts and a bunch of rest. I attributed it to serious overtraining syndrome. It's one of the main things I'm trying to avoid this season, despite my desire to add volume and performance.

I did a little digging around from time to time online. Searching terms like "lung pain running", "lungs waterlogged", etc but never really finding anything. Last night I finally found some interesting stuff by looking at the terms "pulmonary edema exercise."

The first thing I saw scared the bejesus out of me: In patients with left ventricular failure during exercise, pulmonary vascular pressure increases more markedly than in normal subjects.1,2 Indeed, the left ventricle dilates early and significantly during exercise1 because of an increase in venous return, systemic arterial pressure, catecholamine levels, and central blood volume and failure of the heart to keep up with increased cardiac work that results from an increased heart rate and shortened diastolic period. Therefore, leakage of fluid from the pulmonary vasculature into the pulmonary interstitium could be enhanced depending on the increase in transcapillary fluid pressure.

Left ventricular failure? I'm not a heart surgeon but that ain't good. Reading the article though I found that they were focusing on people with V02Max in the 10-20 range... people who can likely not make it up a flight of stairs. Not exactly me (except for after plyos). Still, it was scary.

The second article I found was called "Intense exercise impairs the integrity of the pulmonary blood-gas barrier in elite athletes": The blood-gas barrier must be very thin to allow gas exchange and it is therefore subjected to high mechanical stresses when the capillary pressure rises. In some animals, such as the thoroughbred race-horse during intense exercise, the stresses are so large that the capillaries fail and bleeding occurs. We tested the hypothesis that, in elite human athletes, the high capillary pressure that occurs during severe exercise alters the structure and function of the blood-gas barrier. ... These results show that brief intense exercise in athletes with a history suggestive of lung bleeding alters blood-gas barrier function resulting in higher concentrations of red cells and protein in BAL fluid. The lack of activation of proinflammatory pathways (except LTB4) in the airspaces supports the hypothesis that the mechanism for altered blood- gas barrier function is mechanical stress.

At least in this one we're talking about elite athletes... not that I'm elite... just that it's likely a closer comparison to me. Good news is that they're not talking about this symptom killing people. Bad news is that they say it's not fluid so much as blood. The phrase "athletes with a history suggestive of lung bleeding" leaves me scratching my head... do I have such a history? The conclusion is that my waterlogged feeling is caused by "mechanical stress." This makes sense to me. Breathe in and out more rapidly than normal for long periods of time and it strains the tissues. Little alveolar blisters. Or a lung overuse condition.

The last article called "Changes in the Blood-Gas Barrier in Elite Human Athletes" is very interesting: The extraordinary findings in Thoroughbred racehorses that all animals in training break their pulmonary capillaries raises the question of whether elite human athletes can alter the integrity of their BGBs at very high levels of exercise. There are several anecdotal accounts of hemoptysis or hemorrhagic pulmonary edema in high-performance athletes. For example, hemoptysis and hemorrhagic pulmonary edema were seen in two athletes who took part in the extremely challenging Comrades' Marathon in South Africa. This race is over a distance of 90 km and the competitors run for 8-11 h. Neither of the two athletes in whom the condition developed had evidence of heart or lung disease, although both of them had previously experienced hemorrhagic pulmonary edema in a similar race. Hemoptysis and pulmonary edema also was described in eight swimmers taking part in a time trial, although fluid loading to prevent dehydration may have been a contributing factor. Another report described three cases of swimming-induced pulmonary edema with opacities in the chest radiograph that rapidly resolved when the patients were rested. One of the authors of that report recently has found a number of additional cases in naval recruits undergoing a strenuous swimming program (Mahon RT, personal communication, 2003). Hemoptysis was common, and there were radiographic opacities that resolved over a period of 24 h after rest. The combination of hemoptysis, edema, and rapid recovery strongly suggested stress failure of pulmonary capillaries. There is another report of a 35-yr-old rugby player who repeatedly developed hemoptysis after extreme physical exertion during games. Extensive investigations produced negative results, except that blood could be seen coming from peripheral regions of the lung at bronchoscopy. Some athletes will remember old-time trainers whose admonishment was to run "until you taste blood."

After this one I feel much better. The author cites a number of examples of endurance athletes getting this sensation. Swimmers. Runners. Misery loves company. And fear of death by blood suffocation loves it too.

I love the last little bit about old-time trainers telling runners to run "until you taste blood." When I read this I realized that I do at times taste blood after long workouts. It's not a blatant taste but it's definitely there. Old-timers.

Here's another article, focused on swimmers.

In the end it appears that blood leakage into the lungs is at least somewhat common for endurance athletes and isn't anything for me to worry about. Of course, I don't want to take it to the chronic level as I did last year. And I do want to find hurdle points because in races losing lung efficiency isn't exactly a good thing.

Well, either that or I have a leaking left ventricle. In high school I had surgery for a vein that connected to the inferior vena cava (the equivalent of the aorta but for the lower half of the body). The vein was apparently leaking blood back down through a faulty valve causing a vericose vein in my netherregions.

Maybe faulty valves are in my genes. Good work Joe and Carol... seriously... could you have done a little more homework before gettin' it on? V02Max of 80+ woulda been nice... and working heart valves.

Amateurs.