Re: Running in marathons impairs immunity

In article <[EMAIL PROTECTED]>,
 John 'the Man'  <[EMAIL PROTECTED]> wrote:

> Once upon a time, our fellow Van Bagnol
>    rambled on about "Re: Running in marathons impairs immunity."
> Our champion De-Medicalizing in sci.med.nutrition retorts, thusly ...
> 
> >The headline of the article is stating that vitamins are not a panacea, 
> >a statement supported by the research it cites. And while marathon 
> >running may be somewhat off the beaten path (so to speak), endurance 
> >activities aren't really so uncommon as to be "bizarre circumstances".
> >
> >And if _you_ didn't care, why post the article to begin with?  :-)
>
> Why, how now, kinsman! wherefore storm you so? -- Romeo and Juliet

That you taste with a distempered appetite. 'Twere better to take those 
things for bird bolts that you deem cannon bullets. -- Twelfth Night

 
> This article brings up the topic of exercise impairing immunity. :)
> Or more precisely, exercising the WRONG way can impair immunity rather
> build it.

Even more precisely, exercise (and overexercise) causes a _transient_ 
reduction in immunological measures, but the long-term effect is that 
moderate exercise improves immune response and reduces incidence of 
illness.

Your posturing was analogous to arguing that intense exercise is bad 
because fatigued muscles after a heavy workout make you more susceptible 
in a mugging when you leave the gym -- although in the long term you 
become stronger and better able to fend off muggers. While I agree with 
your basic tenet that moderate exercise is less harsh to the body's 
defenses than extreme exercise, I'm surprised by the shade of apparent 
sensationalism by which you presented it.

Not everyone runs a marathon, and certainly not three times a week for 
exercise; it can be argued that people who do, exercise _in order to_ 
run them rather than the other way around. They assume the risks when 
they do.


> The research that I had referenced was written by the same author who
> was interviewed in the article on vitamins.

I know. The article you cited was a review/tutorial of prevailing 
sentiment in exercise immunology rather than the actual research but it 
basically echoed the research findings. No problem with that.


> >> "Many components of the immune system exhibit adverse change after
> >> prolonged, heavy exertion lasting longer than 90 minutes."  Thus, 90
> >> minutes should be the maximum length for all workworks, particularly
> >> for continuous exercise activities.
> >
> >Your conclusion is faulty. The story states impaired immunity for a 
> >(depending on system) 3- to 72-hour period of time after...
> >
> >    (A) Prolongued heavy exertion
> >    (B) For more than 90 minutes
> >    (C) Without a break
> >    (D) Without carbohydrate replenishment
> 
> What is faulty is trying to dream up ways, like taking vitamins, in
> order to continue to engage in dangerous activities for who knows what
> reasons.

You seem to agree with a point of the article (vitamin-taking doesn't 
cure everything), but in your post you dismissed it as "another idiotic 
health news story that babbles on about vitamins not being effective".

The point I question is your claim that 90 minutes should be the maximum 
length for "all" workouts. The conclusion does not follow from the 
evidence presented; you were making some hidden assumptions about the 
goals of all workouts.


> Excessive drinking of fluids, including carbohydrate replenishment,
> can and has resulted in death during periods of excessive exercising
> by the way.   This happens quite a lot in marathon running.  :)

We're getting off-topic, but if you looked at the actual cases of 
fatalities, it was hyponatremia (extreme sodium loss from excessive 
perspiring) that was the cause, misdiagnosed as dehydration and 
exacerbated by administration of plain water to treat the dehydration. 
Carbohydrate replenishment and immune response were not factors. (Shock, 
on the other hand, was.) And if you check labels, you'll see that most 
carbohydrate-replenishing beverages also replenish lost electrolytes.


> >...which the interviewed researcher attributes to the stress response 
> >kicking in. To reduce the stressor, it would appear that you could do 
> >any _one_ or more of the following:
> >
> >    (A) Exercise less intensely
> > or (B) Exercise for a shorter period
> > or (C) Take breaks
> > or (D) Keep your carbo stores up (don't bonk)
> > or (E) Take care of yourself as you recover after exercise.
> >
> >It doesn't follow that you should _never_ work out for more than 90 
> >minutes.
> 
> I am suggesting that there always are limits.  That perhaps 90 minutes
> is a reasonable limit.  And, that the reason would be impaired
> immunity.   Other reasons, might be dropping dead from heart attacks,
> etc.  :)

I would have had no problem with you stating that 90 minutes is a 
reasonable limit in order to mitigate immune system stress. I _did_ have 
a problem with you stating 90 minutes should be the unequivocal maximum 
for _all_ workouts. If the former is what you actually meant, then your 
wording conveyed something else.

In another post I listed eight fitness goals for which aerobic exercise 
is utilized. Doubtless there are more, as well as more for nonaerobic 
exercise. But each has its reasons and exercise parameters which are 
sometimes in conflict, sometimes in concert with the others. It would be 
folly to impose an absolute limit on all of them just to avoid one 
possible side effect under certain conditions.


> >> By paying attention to your exercise intensity, such as with METs, it
> >> is better for your heart to cram more intensity into a shorter workout
> >> than to perform low-intensity activities over a longer duration.
> 
> >Once again, I don't see how you can logically reach that conclusion 
> >about the heart. Care to explain?
> 
> A lot of recent research suggests that exercise intensity counts,
> rather than duration.  And, that low level exercising,m like walking,
> simply does not protect your heart very well.
[...]
> Tanasescu M, Leitzmann MF, Rimm EB.
> Exercise type and intensity in relation to coronary heart disease in 
> men.
> http://www.fchn.org/fmh/wmchh/articles/oct/exercise_type_intesity_cad_men.pdf
> JAMA. 2002 Oct 23-30;288(16):1994-2000.

Hmm, the study you mention above categorizes "high-intensity" exercise 
as 6 METs or above, putting walking at a little over 4 mph (14-minute 
mile) in that category -- the same as pitching softball. Incidentally, 
the study also showed a reduction of risk with even 2-3 mph walking 
(Table 5, page 1999).

The above-mentioned study is a good reference. But as it hadn't been 
introduced, I didn't see how your statement could have been derived from 
the marathon/vitamin/immunity article.


> The higher the exercise intensity the better the exercise is at
> avoiding death from heart conditions.  Of course, I would also suggest
> that just like with exercise duration there are reasonable limits to
> exercise intensity, too.

And the higher the intensity, the greater stress to the immune system, 
thus there _are_ tradeoffs to various benefits from exercise.


Van

-- 
Van Bagnol / v a n at wco dot com / c r l at bagnol dot com
...enjoys - Theatre / Windsurfing / Skydiving / Mountain Biking
...feels - "Parang lumalakad ako sa loob ng paniginip"
...thinks - "An Error is Not a Mistake ... Unless You Refuse to Correct It"