Super Normal Physiological Activity
While at a graduation party for one of our friends kids I struct up conversation with a cardiologist who was also attending. He commented that running a marathon is a super normal physiological activity and men aren't made to engage in this activity. To prove his point he noted that perfectly healthy people die while participating in marathons on a regular basis. On a hot day he commented that dehydration mixed with drops in blood pressure lead to heat stroke, then heat exhaustion and bigger problems with the heart. Scared the bejezzus out of me.
When I told him I had done an IM, then explained the distances required, he thought I was nuts. He was not against exercise, but thinks there are practical limits to what we can ask of our bodies. He also suggested that by the time we feel symptoms like being light headed, we are already behind the problem and possibly in danger. Any thoughts on these comments from this non-endurance participating physician?
Comments
Ok - gathering some materials ... be right back.
They do train for IM or they wouldn't be here. Perhaps one of them will weigh in...
That said...
There are a lot of assertions in Mr Cardiologist's elevator talk:
"Running a marathon is a super normal physiological activity and men aren't made to engage in this activity."
"Perfectly healthy people die while participating in marathons on a regular basis."
"Dehydration mixed with drops in blood pressure lead to heat stroke, then heat exhaustion and bigger problems with the heart."
None of these should be taken at face-value.
People have been running marathons for a very long time.
It is human to test our limits.
Men weren't made to drive a car an hour to work to sit at a sesk all day, but I do that too. Who says that we weren't made to run marathons?
Perfectly healthy people die. Rarely, but it happens. From what I've seen, estimates of the risk of dying during an endurance event (marathon, ironman, ...) seems to run between .8/100k and 1.4/100k. So... on the order of 0.001% give or take... if that were my risk tolerance than there's no WAY I'd commute into work on the freeway every day because my odds there are much worse. What I don't know is how elevated this is above the risk of daily death, but this should be deducted from that 0.001% because what you're worried about is the incremental increase in risk.
Dehydration is never a good thing; neither is overheating. Ergo, drink a lot, and take in lots of electrolytes (salt-stick, endurolytes, ... ), do everything you can to keep the machine cool, and if you know you're getting too hot (cramps, headache, tiredness, dizziness) then don't be afraid to stop or slow down.
There is some credibility to the argument that one can exercise too much.
There are these articles:
http://www.drjohnm.org/2011/09/cw-is-the-ironman-triathlon-heart-healthy/
http://athletesheart.blogspot.com/2011/09/ironman-and-heart-health-my-take-on.html
There was this thread:
http://members.endurancenation.us/Forums/tabid/57/aft/10359/Default.aspx
The article refered to in the thread is titled, "One Running Shoe in the Grave"
http://online.wsj.com/article/SB10001424127887323330604578145462264024472.html
LOVE that title...
This generated a lot of discussion.
I especially like Al's comments:
My goal is not to live longer, but to live well, and triathlon provides mental, social, as well as physical benefits which I will not give up unless it's taken from my "cold, dead hand". Specifically, the end point of mortality in these articles is both crude, and not frightening to me.
As a physician, I have had numerous "informed consent" discussion with patients prior to surgery. I note the possibility of death, which is weighed against the benefit of the surgery, which is usually being done not as life saving, but as life enhancing. No one has ever said, Hmm, that's too high a risk, I don't think I'll have the surgery (those folks have probably self-selected out before that point).Point is, humans assess and analyze risk not from a purely econometric perspective, weighing coolly risks and benefits, but rather from what I call "emotional logic" - what's important to me as a person, and how do I improve my sense of self.
John Culberson wrote a very thoughtful response that carries more credibility than I have to offer. Some of his thoughts:
As for endurance exercise causing problems... recovery needs must be met, or illness/injury develops.
The recent hype about deaths during triathlon swims and sudden death in highly trained athletes ignors the fact that bad events happen to people on a rare but regular basis. These events did not occur because the individual was training too much, but happened in spite of training.
My own experience:
I started experiencing exercise-induced a-fib a few years ago, and it really threw me.
I did a lot of research. Then I eliminated other possible triggers (caffeine, esp during training) and increased my sleep and recovery, and the a-fib hasn't been back. I train for and race 70.3, and I don't see IM in my future. I believe I have some physiological limits and I'm happy to live within those limits. A-fib was a clue into those limits for me, and I listened to it and responded.
I summarized my take in this thread:
There is certainly some research to support the argument that exercise is very beneficial to a point, and that exercise beyond a certain point, especially when coupled with insufficient recovery, can negatively affect both longevity and function (heart scarring, osteoarthritis and other permanent injuries).
There is a lot more hype than truth to the notion that exercise will kill you - a lot more.
Rest and recovery absolutely must be part of any healthy routine. Sleep 8+ hours every night. Take a day off from strenuous exercise every week, two days if you're doing a lot of high-intensity training. Eat slowly. Life is not a sprint.
Triathlon training and exercise, like any aspect of life, should be approached thoughtfully.
Listen to your body. Know and accept your physiological limits and live within them. Your limits are your own - different from mine or anyone else's.
If you love training and racing, train! race! Love keeps us going.
Fear not. Go forth. Conquer. Have fun.
Just exercise some judgment as you do so.
http://m.runnersworld.com/health/too-much-running-myth-rises-again
I especially like this quote:
Cox regression was used to quantify the association between running and mortality after adjusting for baseline age, sex, examination year, body mass index, current smoking, heavy alcohol drinking, hypertension, hypercholesterolemia, parental CVD, and levels of other physical activities.
What this means is that they used statistical methods to effectively "equalize" everyone's weight, blood pressure, cholesterol, and so on. But this is absurd when you think about it. Why do we think running is good for health? In part because it plays a role in reducing weight, blood pressure, cholesterol, and so on (for more details on how this distorts the results, including evidence from other studies on how these statistical tricks hide real health benefits from much higher amounts of running, see my earlier blog entry). They're effectively saying, "If we ignore the known health benefits of greater amounts of aerobic exercise, then greater amounts of aerobic exercise don't have any health benefits."
Thanks for the information. I took comfort from the blog posts from Dr. Lawrence Creswell ("Ironman and Heart Health") and Dr. John Mandrola ("Is Ironman Heart-Healthly"). I also enjoyed the EN thread from the physicians who replied. Much appreciated.
I also spoke with my internist who has been practicing medicine for 30 years. He referred me to one of the doctors who specializes in sports medicine and takes care of the Bulls basketball team. He felt there would be docs affiliated with either University of Chicago or Northwestern (where he practices) that either participate in or specialize in endurance athletes. I am going to take his advice. I generally see my doc once a year before the race season gets under way. I am a healthy guy who does not yet take baby aspirin. I may begin this year, will wait to see what my doc suggests.
Stay safe, train hard,
Frank