Another article on endurance exercise & afib

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One of the problems for many of athletes -- and the problem for Endicott -- is that they can't stop asking "Why? How could this happen to someone who has built his life around being active?" It just doesn't make sense to them.

<[espn.go.com]

George – thanks … good explanatory report…especially the concluding comments.

What’s not mentioned and should be noted:

The high production of catecholamines during endurance exercise is known to remove “free magnesium ions by chelating them out of circulation from catecholamine-induced free fatty acids”… which would help explain the arrhythmia factor.

Also not mentioned is the excessive production of inflammatory cytokines and overproduction of free radicals or reactive oxygen species (ROS) from long-term heavy breathing during endurance exercise which damage cells and cause cardiac fibrosis.… which is the physical interference that causes the cell-to-cell-to-cell communication in the cardiac myocytes.

This, of course, leads to ischemic tissue (when the heart muscle doesn’t get enough oxygen) which then, ultimately, causes permanent tissue damage or necrosis. (necro = death). That’s why some endurance athletes are permanently damaged since dead tissue can’t be regenerated.

While the report doesn’t address the magnesium deficiency issue, it’s long been known MgD lies at the ‘heart’ of endurance exercise complications which would include arrhythmia… ie, from magnesium expert, Mildred Seelig’s , teachings:

Auto-oxidation of catecholamines yields free radicals, which explains the enhancement of the protective effect of Mg by anti-oxidant nutrients against cardiac damage caused by beta-catecholamines. Thus, stress, whether physical (i.e. exertion, heat, cold, trauma - accidental or surgical, burns), or emotional (i.e. pain, anxiety, excitement or depression) and dyspnea as in asthma increases need for Mg. Genetic differences in Mg utilization may account for differences in vulnerability to Mg deficiency and differences in body responses to stress.

Mildred S. Seelig, MD, MPH, Master ACN
Consequences of Magnesium Deficiency on the Enhancement of Stress Reactions; Preventive and Therapeutic Implications (A Review) Journal of the American College of Nutrition, Vol. 13, No. 5, 429-446 (1994)


Jackie

Hi
I wonder how much depends on the intensity of the endurance? There are also links between endurance cycling and increased longevity. Summary here [www.bbc.co.uk]
Les

Les,

There seems to be an 80/20 split genetically. The 20% (of endurance athletes) get afib, the 80% don't. If you are part of the 80%, go for it and enjoy the longevity benefit. How do you know in advance? Since I know I'm part of the 20%, I moderate, though I'm not exactly sedentary. The question I ask myself is how much (or how intense) is too much? I'll do short duration HIIT exercise, I do strength and bodyweight training. I don't train for or compete in endurance activities. I've found my keto diet and the strength training allow me to participate in everything I like to do (off piste alpine skiing, rock climbing, hiking, biking, backpacking, kayaking) and also maintain a much lower BMI (22) than when I used to do endurance training (28) and competition (like a race 13 miles from 6,300' to 14,100'). I continue to maintain a low BP 108/58. Fasting insulin <5.

The other interesting question is why is the exercise beneficial? Is it better glucose control, which could also be handled with a low glycemic diet? Is it higher levels of serum CO2 (I'll write about this in detail in some future post)?

George

George - does your info cover the gene mutation that prevents proper assimilation of magnesium? I seem to recall there is a study that indicates that's behind the arrhythmia connection.... or anything else that's dependent on optimal magnesium levels. Looking forward to your report.

Jackie

Hi GeorgeN,

Very interesting Velo News article, thanks for posting the link!

They patients in the article sound like they may have went to less-than-elite EP's.
From the article:

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(paraphrased) Endicot spent 16 hours on the EP table, and they were unable to find the trigger for his V-tach, so they implanted a defibrillator.
...

Zinn hasn't been so lucky. His first (and so far only) ablation attempt failed. Despite the best efforts of doctors to elicit an episode of AT, which involved elevating his heart rate to 300 BPM for four hours, they were unable to locate the abnormal circuitry.

I'm hoping the author is misquoting - I find it hard to believe that an MD would raise someone's heart rate to 50% above physiological max for 4 hours, on purpose.

-Ted

George, you may have seen the TED talk from research cardiologist/runner below regarding exercise and heart health.

[tinyurl.com]

Hi Researcher,

Interesting talk. I knew much of what he spoke and my exercise model pretty well follows what he describes as "best practices." I do long duration activities at low intensity and high intensity activities are short duration.

Thanks!

George

Today - Stretching (PT targeted), 90 second plank, 50 pushups, some TRX upperbody, pullups, 22 mile slow (I am always slow ) bicycling. This would be a pretty typical day - the cardio can vary between swimming, fast walking, bicycling or some combination of two of these. Some of the bicycling will be similar to HIIT - especially single track.

I don't push too hard. I think age is slowing me down a bit.

NSR for 10 years now after Natale ablation. Approaching 76yo.