
How Strenuous Exercise Affects Our Immune System - hvo
https://www.nytimes.com/2018/04/25/well/move/how-strenuous-exercise-affects-our-immune-system.html
======
nimbius
As a machinist and building maintenance engineer, I can almost guarantee any
ill feeling you're experiencing after a trip to your local gym is due to the
air quality.

Gyms are rarely purpose built facilities. Rather, theyre rented and renovated
spaces. In turn, airflow in the structure is planned for light industrial or
office space. Almost no thought goes into the fact that gyms are sometimes
hundreds of occupants moving the air at two to three times what the OSHA or
planning documents indicate. Paints with VoC's, sealants, and even offgassing
plastics from gym mats or new equipment can turn the air quality from decent
to garbage in a few hours.

I was once contracted to fix an air handler issue at a fitness center. The
root cause was a set of 6 un-ventilated panini presses that were placed near
the front desk as part of an effort to sell snacks and sandwiches. The added
smoke and particulate had decreased the filter life and burned out a blower
motor. The solution was either get rid of the electric grills, or start
replacing 30 day filters every week.

~~~
awakeasleep
You’re not even mentioning CO2 concentration. I work in a large, open office
with seemingly sufficient airflow, but after buying a CO2 detector on a whim
I’ve seen that it frequently reaches 1200ppm, and you actually can tell that
you feel like crap when that happens.

I can’t imagine if the whole office was filled with people exercising.

~~~
mrfusion
What does it feel like as it starts getting higher?

~~~
DoofusOfDeath
I don't know, but I'd love to see some study on the impact of CO2 levels on
the measures we typical care about regarding meetings: levels of alertness,
qualities of social interaction, decision-making speed/quality, etc.

~~~
graeme
Harvard published an interesting one a few years ago. Having trouble tracking
down the link on mobile, but here's an overview:

[https://thinkprogress.org/exclusive-elevated-co2-levels-
dire...](https://thinkprogress.org/exclusive-elevated-co2-levels-directly-
affect-human-cognition-new-harvard-study-shows-2748e7378941/)

~~~
neuronexmachina
Here's the study link:
[https://ehp.niehs.nih.gov/15-10037/](https://ehp.niehs.nih.gov/15-10037/)

> Associations of Cognitive Function Scores with Carbon Dioxide, Ventilation,
> and Volatile Organic Compound Exposures in Office Workers: A Controlled
> Exposure Study of Green and Conventional Office Environments

> ... Methods: Twenty-four participants spent 6 full work days (0900–1700
> hours) in an environmentally controlled office space, blinded to test
> conditions. On different days, they were exposed to IEQ conditions
> representative of Conventional [high concentrations of volatile organic
> compounds (VOCs)] and Green (low concentrations of VOCs) office buildings in
> the United States. Additional conditions simulated a Green building with a
> high outdoor air ventilation rate (labeled Green+) and artificially elevated
> carbon dioxide (CO2) levels independent of ventilation.

> Results: On average, cognitive scores were 61% higher on the Green building
> day and 101% higher on the two Green+ building days than on the Conventional
> building day (p < 0.0001). VOCs and CO2 were independently associated with
> cognitive scores.

> Conclusions: Cognitive function scores were significantly better under
> Green+ building conditions than in the Conventional building conditions for
> all nine functional domains. These findings have wide-ranging implications
> because this study was designed to reflect conditions that are commonly
> encountered every day in many indoor environments.

------
marban
I've been running for twenty years and am currently on a half-year streak with
around 15km / day. In all those years I've been sick for about two weeks all
in all. Before working out, that was like the average over half a year.

Conclusion: Figure out what works for you, have a daily routine, add a bit of
obsession and stop reading stories about the pros and cons of exercising.

~~~
matthewwiese
Same with me during my peak running period last year; even when I was feeling
ill or off, a run, albeit grueling at the time, always seemed to aid in my
recovery (if only for the placebo of getting myself out of bed).

I really need to start doing it on the regular again...

~~~
orbitur
Prior to my knee injury I was a happy runner, and I definitely found that just
going for longer than 15 minutes would completely clear out my nose if I was
at the congestion stage of a cold.

Of course, my nose would be congested again a few hours later, but it was
still a decent motivator since I hate taking medicine.

Wish my knee would stop being shitty.

------
amorphous
I have one rule: I only ever do sports if I have rested well the night before.
It took me until I reached my 40s to realise that lack of sleep + heavy
exercise = high chance of catching a cold.

Other sure ways how I can get sick: overdo sauna after exercising and, by far
the worst, overdoing cold showers (Jim Hoff anyone? - I got seriously sick
experimenting with that)

I guess the overall strength of my immune system is below average :-(

~~~
crististm
There is a high correlation between insufficient sleep and catching cold. It
kind of made sense but I've looked it up and found several studies supporting
this.

This winter I've tried only cold showers after running outside. Cold showers
as in (sometimes) my neck hurt if I did it too long. Did not catch a cold
until this spring and I think this is more correlated to insufficient
rest/sleep (on top of exercising) than to water temperature.

My takeaway is enough rest is not optional and cold showers are doable even in
very cold water. I have no idea how hard would be a bath in water + ice.

~~~
WillPostForFood
What’s the theory behind the cold shower?

~~~
kristerv
for me it wakes me the f up. It's strong like having drunk coffee or
something. Results may vary of course, but works wonders for me and my focus
during the day.

I know of an old woman who's beed ice-cold bucketing for years and looks great
and hasn't been sick in a long time. Does this with -20C outside too. Yet I
find I may get sick easier if it's too cold outside and I go all out freezing
shower.

~~~
amorphous
I still do cold showers, but just finishing with cold water for a short
interval, 20 seconds or so. That seems to be entirely beneficial (I don't
remember were I read it but there's some other cold shower expert recommending
not going longer than that)

~~~
CodeCube
I've been doing cold showers after working out ... but when I do, I'm freezing
_the entire day_. Does this happen to anyone else?

~~~
r00fus
Does attire affect your temperature perception? I mean, maybe you're just not
wearing enough...

~~~
CodeCube
Nothing different than I usually wear ... t-shirt and jeans, and I keep my
house at 74 degrees (it's usually a bit warmer in my office). Under normal
circumstances, as you can imagine, I find it quite comfortable.

------
jerf
I gotta stash this one away. I often refer to the disaster of 20th century
health science as scientists repeatedly gathering a single point of data and
then drawing a line (or hyperplane) though it, but this is a great article
clearly demonstrating an example of that, and how plausible it all seemed at
the time.

(Not that it's a trend limited to the 20th century. But it seems to me to have
been extremely bad in the health area in that time frame. Not uniquely so
necessarily, but quite bad.)

~~~
knice
I imagine the 20th century was the worst time for it because we had more
sophisticated data collection and analysis methods, but failed to recognize
our own inadequacies when using those tools to draw conclusions.

Kind of like social media algorithms today.

------
ekr
My personal experience with long (100miles+) cross-country mtb riding (with
lots of climbing) is that in fact, catching a cold after such a strenuous ride
is way more common than the base rate. This is also the experience reported by
most professional cyclists (check TdF reports).

My under-researched model of how this happens, is that there is a lot of tear-
and-wear in the muscles where the effort is happening, which leads to
inflammation, and that's where the white-blood cells might end up.

~~~
mistrial9
runners and other endurance athletes I have met over the years, show noted
skin aging after 40 years old..

~~~
stevenwoo
That may be more due to inadequate preventative sunscreen/protective clothing
per outdoor time, every one who spends time outdoors without it shows signs of
skin aging like the a/b test in one, truck drivers, with the side closest to
window showing significantly more wear and tear versus the interior facing
side. In addition to sunscreen, there are nowadays a lot of arm/leg covering
just for SPF protection even in hotter temperatures - I always wear the arm
protection/eyewear when outside.

~~~
vba
Eyewear? Like sun glasses. Do the eyes age from natural light?

~~~
sideshowb
Yes. Macular degeneration from uv. Sunglasses and car windscreens in the eu
must protect against uv by law. Other windows not necessarily.

I have an optometrist friend who says he can tell easily in eye exam which old
people have worn glasses or sunglasses and which haven't.

------
Bartweiss
The standout quote for me: "[immune cells] moved elsewhere, migrating to the
animals’ guts or lungs, portions of the body that might be expected to need
extra immune help after hard exercise".

Rapidly producing immune cells during exercise, then letting them (and more)
die off would be a baffling response. But pumping them into the lungs (because
you've been breathing hard through your mouth) and gut (for when you make up
lost energy, and maybe eat some raw meat you've been hunting)? That makes a
great deal of sense.

That effect is unconfirmed in humans, but it would ground our observations in
an evolutionarily-sane outcome.

~~~
Retric
Exercise pushes stuff around in your gut which is probably more directly
related to the immune response than the possibility of eating raw meat.

~~~
boris
Why would you go run (hunt) if there is still stuff (food) in your gut.

~~~
DamnYuppie
Best to hunt when you are loaded up on fuel. Don't want to be hunting when
energy is low as you will most likely be less successful as your focus,
patience, and response times will all be lower.

Hunting isn't like going to the store, success isn't guaranteed.

~~~
donovanh
I think the opposite. People that fast for a period (> 16 hours) report
improved energy levels. This may be because after a while the body enters a
ketogenic state where it burns body fat, which is a great source of energy and
perfect for when on the hunt.

~~~
naasking
> I think the opposite. People that fast for a period (> 16 hours) report
> improved energy levels. This may be because after a while the body enters a
> ketogenic state where it burns body fat, which is a great source of energy
> and perfect for when on the hunt.

Ketogenesis requires over a week of carb restriction IIRC. I think fasting
yields energy because the body increases various stress hormones to push you
to find food so you don't starve.

~~~
dorfsmay
No, it has to do with insulin levels. Google "Jason Fung insulin".

------
mkirklions
This article doesnt make mention of my workout where I lift something heavy 1
time.

I had the idea that I wanted to reduce time in the gym, so I used the
potential energy equation

PE= M _g_ h

I'm not getting any taller, so the only thing I could change was either the
reps or mass of weight moved.

I made it my goal to lift heavy weights so I'd only need to deadlift 1 time
and be able to pig out.

TBH, it works, I lose 1 lb a week eating 3,000 calories a day. We lift 2 times
a week. Warm up, then do 2+ reps of a heavy set.

I dont really sweat after a workout, but I look pretty big and I'm still
deadlifting 450lbs. But I only deadlift that weight 1 time a week.

Is that 'Strenuous'?

~~~
flcknzwrg
Found the fatty ;)

Ok, seriously.... math: if you eat 3000 kcal per day and lose 1 lb per week,
you're burning 3500 kcal per day. This is quite a lot. It's near impossible
unless you work out a lot and are veeeery muscular... or are impossibly
tall... or, well, fat. (Or a combination of those.)

Take me for comparison: I am 187cm (6'1ish) tall and weigh 75kg (165 lbs),
pretty much smack in the middle of the "normal weight" range. I like running,
do about 50km (30 miles) per week. I count calories and let my wrist watch
measure my energy expenditure 24/7\. On rest days (mostly sedentary), I burn
about 2100 kcal. To get up to 3400, I have to do some sort of hard run and
some lighter activity in addition, or do a long run (18km+).

Now I'm not everybody of course, but you can't be that abnormal, right? So I'm
not buying your numbers.

~~~
sternocleidom
Running is probably the worst sport as far as caloric expenditure is
concerned.

A serious endurance cyclist or swimmer will certainly go through 3000 kcal on
a normal training day if not more.

I've burned an estimated 5000kcal daily on the bike for weeks. What's more is
I know these numbers are very accurate as we train with power meters that
record our energy expenditure with minimal error.

It's important to distinguish between serious athletes and average people who
exercise. It's possible that truly competitive athletes - for instance, who
run 120 miles a week to your 30 - will be much more likely to get ill from
their efforts. It can take serious fitness - and a mentality acquired only by
years of serious training - to push yourself to the extent that you fall ill,
and maybe the recreational "athlete" described in this text can't reach that
point.

~~~
mrfusion
Why do you think cycling would burn more calories than jogging?

~~~
sp332
Jogging is very efficient, mechanically speaking. You're not going to burn a
lot of calories per hour.

~~~
smnplk
You need to put more effort in 1 hour cycling session to burn the same amount
of calories as in 1 hour running session. Running activates more muscles.

~~~
riku_iki
But cycling affects largest human muscles, which work more intensively..

~~~
smnplk
I was "professional" athlete many moons ago. When we measured max heart rate,
we did it on a bike first and then on a treadmill running and then bike again.
My max heart rate running was +5 beats allways and I was not a single case. I
just couldn't get to my max heart rate while cycling.

------
will_c03
So this is very interesting to me as a swimmer. I find that at the peak of my
curve (where I train harder for the regional meet) I often get sick more
often, and for far longer. In swimming, this is catastrophic to your
performance for the meet, so we try at all costs to prevent illness, but it
always happens to one or two of us. The question I pose, does this just apply
to shot term exercise, or does intense training (5 hrs a day) for about a
month have the same effect.

------
evo_9
Started doing Tabata sprints a couple years ago. Amazing how much more
effective they are versus running at a slower pace for 40 minutes (my old
routine).

Also, never knew this, they make self-powered treadmills which are really
ideal for sprinting on. I just bought a ASUNA Hi-Performance Cardio Trainer
Self Powered Manual Treadmill, it's pretty much ideal for Tabata/sprinting for
a home-gym.

~~~
paulcole
Effective at what?

~~~
evo_9
Effective at maintaining aerobic conditioning. I wanted to get away from
having to run 40 minutes 3 times a week. Doing sprints for 2-4 minutes 3 times
a week is essentially the same.

Also has the added benefit over my old 40 minute jog routine of increasing my
quickness. I play hockey so it was noticeable how much quicker my first 3
strides have become the past 2 years.

Pretty good read regarding all this:
[http://www.bbc.com/news/health-17177251](http://www.bbc.com/news/health-17177251)

~~~
paulcole
Yeah it's not surprising that slow speed jogging wouldn't improve quickness.
Fast twitch vs. slow twitch and all.

------
csours
I have asthma, and I think strenuous exercise is good for my lung capacity
long term, but makes me feel terrible the next day or 2 days after. It's
really difficult to figure out what causes my symptoms and what makes me feel
better.

I wish there was a chip that monitored hormones and immune system factors,
etc.

------
jmcphers
Anecdotally my own experience matches that of the rodents in the experiment.
I've found that when I'm getting regular strenuous exercise (I bike up a steep
hill as part of my commute) I almost _never_ get sick, and can go > 1 year
without so much as a sore throat. Conversely, when I'm more sedentary for
months at a go, I'm more likely to become ill.

~~~
agumonkey
I have asthma and many allergies, whenever I have a cold, 80% chances it's
gonna end up as a long and tiresome bronchitis. In HS, I decided to give no
fuck, went to my 2h winter soccer practice (+ 1h total mudtrail bike to go
there). That cold didnt last long and didnt end up causing bronchitis. That
was surely half luck, but I always have a feeling that, to an extent, keeping
your system active helps. More blood flow ? maybe trigger a more rapid and
global immune response .. dunno

------
jaequery
i think its not the exercise but the rest that follows after a strenuous
activity that makes you prone to get sick. its been my theory that if you rest
like you are on your last breath, your immune system stops being active. but
if you stay active and keep moving your body like you have to survive, your
immune system is boosted.

ive tested this theory time and time and seems to be on point.

there have been a number of times when i was feeling sick and instead of
resting, id go out in the cold freezing and walk outside for hours. next day i
would be completely healed.

but when im just home bed ridden that sickness can linger for days or even
weeks.

im also a huge fan of taking cold shower the moment you feel like you are
carching a cold. it works way too often to be a coincidence.

------
wallace_f
>athletes are lousy at identifying whether and why they are sniffling.

Not an expert, but wonder if this is caused by a hangover from the endorphin
dump from the marathon. I felt that way afterwards.

------
jhayward
Anecdotally: when I was a bike racer I noted that if I was so exhausted after
a hard training ride (usually 5+ hours, >100 miles) that I was involuntarily
falling asleep afterward that I would inevitably come down with a sore throat
leading to a cold within 12-24 hours. 100% of the time.

I've had maybe 2-3 colds in the decades since I quit racing.

~~~
marban
What was your hydration and nutrition like post/pre?

~~~
jhayward
Hydration was completely insufficient, I realized much later. Nutrition was
the typical medium-to-large meal after a shower/nap. There was often a long
car ride home, an hour or so.

------
atomical
I guess this research is wrong then?

[https://nutritionfacts.org/video/preserving-immune-
function-...](https://nutritionfacts.org/video/preserving-immune-function-in-
athletes-with-nutritional-yeast/)

------
smnplk
Anyone else noticed that endurance athletes look 10 years older ?

------
itaysk
Kudus to NYT for stating the TL;DR right at the top, instead of exhausting the
reader with meaningless paragraphs.

> The review concludes that, contrary to widespread belief, a long, tiring
> workout or race can amplify immune responses, not suppress them.

Would be even better if that was reflected in the title, but alas, my
expectations from a modern website are not so high.

------
sternocleidom
This article could not be more wrong, and anyone who has been a truly serious
athlete will agree with me.

There are perhaps a dozen times in my life when I was training with abnormally
high intensity even for a very competitive endurance athlete and fell ill
immediately afterward.

These range from 2 hr brutal races to 3-4 days of 5-7 hrs daily intense
training or race efforts. I very rarely catch a cold, but it's more often than
not after an effort that stands out to me as memorably difficult.

Any serious cyclist will agree with me. Even competitive high school athletes
know that you are most likely to get sick right before taper.

This is an example of misinterpretation of scientific experiment, most likely
by the journalists but possibly by the scientists themselves.

EDIT: I don't take issue with "immune response is heightened after exercise".
I'm sure it is. I take issue with this quote: "But it is unlikely to have made
you vulnerable to colds or other illnesses afterward, according to a myth-
busting new review of the latest science about immunity and endurance
exercise".

~~~
jxcl
This is all anecdotal evidence that's pretty well countered by this statement:

> Their first conclusion was that athletes are lousy at identifying whether
> and why they are sniffling. The original 1980s studies had relied on
> runners’ self-reports of illness. But newer experiments that actually tested
> saliva showed that less than a third of marathon runners who thought they
> had caught a cold actually had. Statistically, their odds of becoming sick
> were about the same as for anyone else in the race’s host city.

~~~
sternocleidom
The anecdotes of hundreds of national and world class athletes I have trained,
raced, and interacted with over the years is worth more than any study you can
paste here, my friend.

I suppose you are unlikely to see anyone here back me up since HackerNews
isn't exactly an athletic demographic.

Fever, red eyes, overflowing mucus, extreme soreness and raw throat for days
or over a week - are you trying to tell me that this isn't sick? Maybe that's
your normal state, but I've seen hundreds of cases of amateur and professional
athletes reduced to this shortly after performing national caliber efforts.

~~~
WhompingWindows
The problem with anecdotes is there is no transparency or verifiability to
that data, it's all in your inherently biased memory and mind. Real data is
not perfect, but at least I can plug it into my R and see if we get the same
results after analysis. If you feel passionately about it, perhaps you can
create a survey instrument to gather the data about your trainees, I'd be
happy to analyze that data.

