Human factors : why is flying so tiring

[CVividasku]

Hi

I have now more than a 1000 hours on the bus, and I've noticed that I'm experiencing a special type of fatigue on a regular basis.
I am a night owl rather than an early bird. So it's no surprise that I experience some fatigue if I woke up too early without sufficient sleep. This is not really my question.
My question is about fatigue not related to insufficient sleep. For example, after 3 flights in the afternoon, say a 2PM-11-PM shift, I will experience a weird sort of fatigue during the 4th flight (it's also starting to grow during the third). It's similar to sleep related fatigue but it's not, because as soon as I come home, I'm very awake and unable to go to bed before 3AM.
I'm not really able to explain or even describe this type of tiredness.
Sometimes, a word that comes to mind is "weariness", fatigue related just to the routine nature of the activity and the fact that there still is pressure to do everything right, even if it's easy on a given normal day.

Am I the only one to experience this ? If not, are there ways to lessen this feeling ?

Thanks

[AerocatS2A]

You can be sleep fatigued but also feel alert and unable to sleep later on. I’ve always needed an hour or so to “wind down” even after an all nighter. I also used to suffer greatly from being dog tired but not sleepy.

[Paulm1949]

Could it be the cabin air you’re breathing in? What’s in the air? And being in a pressurised cylinder as well.

[sonicbum]

Hi

I have now more than a 1000 hours on the bus, and I've noticed that I'm experiencing a special type of fatigue on a regular basis.
I am a night owl rather than an early bird. So it's no surprise that I experience some fatigue if I woke up too early without sufficient sleep. This is not really my question.
My question is about fatigue not related to insufficient sleep. For example, after 3 flights in the afternoon, say a 2PM-11-PM shift, I will experience a weird sort of fatigue during the 4th flight (it's also starting to grow during the third). It's similar to sleep related fatigue but it's not, because as soon as I come home, I'm very awake and unable to go to bed before 3AM.
I'm not really able to explain or even describe this type of tiredness.
Sometimes, a word that comes to mind is "weariness", fatigue related just to the routine nature of the activity and the fact that there still is pressure to do everything right, even if it's easy on a given normal day.

Am I the only one to experience this ? If not, are there ways to lessen this feeling ?

Thanks

These are likely the symptoms of increased cortisol levels, which are quite common in our profession. Sleeping alone won’t suffice to bring it down and sometimes you won’t be able to achieve a good sleep due to those high levels.
You need to disconnect for a while and engage in relaxing activities and light physical exercise. Try also getting bored; when you’re to hyped up between flights and possibly other company related engagement such that you feel you’re close to your maximum EGT, switch off. Do nothing. Look for boredom and hang there for a while. It works a bit like a computer reset. Whatever you do, make sure you engage in something you really enjoy - it is the best way to rebalance hormone levels.

[Uplinker]

I don't know the answer to your question, but the way I dealt with tiredness and fatigue were to give up caffeine, going jogging, and watching my diet.


Caffeine makes you alert, but it stays in your system for 8 hours and prevents you from sleeping properly. Caffeine wakes you up, but caffeine during the day prevents you from sleeping properly, so the next day you are tired and need caffeine to get going again and it becomes a bit of a treadmill.

If you need to sleep down-route, I found that caffeine prevented me easily going to sleep in the afternoon for a night flight. Stopping coffee completely, enabled me to sleep at odd times of the day. I stopped caffeinated coffee, and drink tea or just hot water in the cockpit. (Tea also has caffeine but for some reason it is not absorbed as it is with coffee).


It is important to keep fit, because it just is - you need to keep your whole body slim, fit and functioning to give yourself the best chance of staying healthy and fending off disease, such as cancer etc. But sitting for hours making no physical effort is very bad for our health. The human body is very good at saving energy, so we need to "tell" our bodies to keep working: maintaining our organs and muscles at peak performance.

Going to the gym is one way, but the whole gym process can work to prevent us actually doing it ! Having to sign up to a subscription and be a member. Having to book sessions. Having to pack a bag with shower stuff and a change of clothes. Having to drive and park, or travel to the gym. Having to wipe down the equipment after use, etc, etc. It is not surprising that many just can't be bothered.


Jogging on the other hand is really easy. You can just decide to go jogging whenever you want. Put on a decent pair of running trainers and literally jog from your front door. You can go anywhere, even just along the streets (pavements) around your house. I do that, but also along the canal, river, sea front; through the woods, along footpaths, across the common or moorland etc, whatever is there. And when you get back home - straight into your own shower. No booking, no subscription, no bag of shower gear, no traveling, no parking.


And no time is wasted. Whereas a gym visit can easily take a couple of hours overall; jogging from your front door takes just a long as the jogging takes. Only got an hour?, perfect for a 5km jog.

Jogging also allows you to unwind and de-stress after a duty - I go jogging down-route, often when I wake up very early owing to jet-lag after flying in. Super easy to do.


Diet wise, I try to avoid all sugar and salt. Sugar has a similar effect to caffeine but with a much shorter cycle: Snacking on biscuits in the cockpit gives you a sugar rush which perks you up, but then you get a sugar crash. So then you want more sugar. Our bodies convert sugar straight into fat which it stores. Sugar is super dense pure 100% calories and it is really bad for you.


Salt raises our blood pressure over our lifetime, we actually only need a tiny amount of salt per day.


Anyway........Sorry for the really long post - I went off on one there !! Perhaps I need to go for a run, to de-stress a bit ! :D

[Sleeve Wing]

Disturbed biorhythms......... ? I found that all my experiences were due to cumulative tiredness. Max duty periods followed by min. rest periods. Captains' discretion being assumed by crewing, to complete the duty. "Days off" working expected during the Summer. It all adds up.............

[Bergerie1]

Better than running, try the Canadian Air Force 5BX plan. Also, use the stairs as often as possible rather than the lift.
https://csclub.uwaterloo.ca/~rfburger/5bx-plan.pdf

[Uplinker]

Wow. I am sure the 5BX would make you very fit. BUT, it is very complicated, and requires remembering lots of moves and tables of numbers and timings, and I think many couldn't be bothered with it all.


The very best exercise is the exercise that you will readily and regularly do.


For me, jogging is really really simple, and does not require me to follow any regime - or count any thing. Which releases the brain to think about anything you want. Or nothing. And I never time myself or measure myself, nor run to a beat. I just go at the pace that suits me. That's the ease of it, you just gently plod along. I look around me and listen to the bird song, say hello to the cows, see where that footpath goes etc, And it hardly seems like exercising, it's just jogging along and you get automatic fitness.


BTW, yes, use stairs wherever possible, which is also free and easy exercise :ok:, (I am too impatient to use lifts, which keep stopping to pick other people up !!).

[SWBKCB]

Agree with everything Uplinker says - no mention of age in the posts, so I'm assuming the OP is still relatively young, but as you get older you get tired more easily. Obvious, I know but something to consider.

[Bergerie1]

SWBKCB and Uplinker, You are both absolutely right. I used to do 5BX a long time ago during my flying days but now, at my age, walking and some simple exercises for Seniors from this man help to keep me going:-

https://www.youtube.com/watch?v=dMQbzlBr2VM

And this one too to help balance and walking as we age:-

https://www.youtube.com/watch?v=Xcg8zKFnOAU

[tdracer]

Back in the late 1980's, I was heavily involved in the flight test program for the 767 re-engine program. As I result, there was a month where I flew nearly every day (flight testing is 7-day/week program, so no assurance of getting even one day off - since then they implemented a rule that required at least on day off every 14 days but that wasn't the case then).
Thing is, on most of those flights I didn't do anything besides sit in the back - either reading or looking at the view out the window - and munch my flight lunch. My testing was 'contingency' - if they couldn't find the calm air they needed for the various aero such testing planned, they'd run my tests instead. So long as they could find 'air', I literally had nothing to do.
By the end of that month, I was a zombie - totally exhausted (and I was in my early 30's at the time so it wasn't age). It simply amazed me that I could get that exhausted just sitting. I assumed that stress was a big part of it - flight testing is inherently stressful - although nothing we did was considered 'high risk' - flight testing was incredibly expensive (I heard numbers of $50,000 hr. - probably double that today), so everything was always 'rush-rush'. If someone asked you a question about your test, you didn't get 15 minutes to think about it, they wanted an answer right NOW! Plus the whole environment was stressful - you could almost feel it in the air. Worse, I didn't sleep well - between the residual stress and lack of physical activity, my brain was fried but my body wasn't that tired...

[MechEngr]

Could it be the cabin air you’re breathing in? What’s in the air? And being in a pressurised cylinder as well.

At cruise altitude the cylinder is depressurized vs the pressure on the ground.

[70 Mustang]

Could there be some "components" in the human body that are "sensitive" to travel in ways that could be similar to those found in other species, such as birds? Perhaps sensitive to changes in the magnetic field, sunlight angles along with the obvious pressure changes?

Parts of our body may "know" that we've traveled significant distances whilst sitting on our arse and pushing buttons. We are well aware of the lower humidity in most flightdecks, along with other well known factors.

Then again, just sitting at one's desk at home, in a restricted position, (without the relatively frequent up and downs for coffees, loos, snacks, etc, that happen in home settings) for 4 to 8 hours, could be just as fatiguing as a flight of equal length of time?

[CW247]

Feeling the same more and more. Feel my health deteriorating by doing this job. Part time awaits. The ugly truth is we humans were not designed to fly 3 days in a row. The noise, the air, the lack of opportunity for good meals and quality toilet time all contribute to fatigue and tiredeness whilst looking perfectly legal on paper. It's become the industry norm to throw you into an extreme block of duties only to then give you blocks of days off. I would much rather have a day off after each day of flying to recoup. The body needs it.

[Uplinker]

@ tdracer, that is very interesting. So more than likely, it is the constant low-level stress for hours on end, combined with moments of high workload and stress, that leads to tiredness and fatigue.

Obviously pilots are under this pressure all the time while in control of an aircraft.

Makes it all the more important to de-stress. Physical exercise is a very good way of de-stressing, and keeping fit, slim and healthy gives the body the best chance of coping.

[hobbit1983]

Feeling the same more and more. Feel my health deteriorating by doing this job. Part time awaits. The ugly truth is we humans were not designed to fly 3 days in a row. The noise, the air, the lack of opportunity for good meals and quality toilet time all contribute to fatigue and tiredeness whilst looking perfectly legal on paper. It's become the industry norm to throw you into an extreme block of duties only to then give you blocks of days off. I would much rather have a day off after each day of flying to recoup. The body needs it.

It also seems to be the industry norm to treat FTLs as targets; even if there was no pressing operational need to.
Sometimes I've got the impression that office staff believe pilots can't possibly be fatigued, if the roster fit FTLs....

[Paulm1949]

At cruise altitude the cylinder is depressurized vs the pressure on the ground.

but you’re still in a pressurised cylinder compared to the ambient pressure that cycles several times on a multi sector day. Not to mention the air

[giord]

Feeling the same more and more. Feel my health deteriorating by doing this job. Part time awaits. The ugly truth is we humans were not designed to fly 3 days in a row. The noise, the air, the lack of opportunity for good meals and quality toilet time all contribute to fatigue and tiredeness whilst looking perfectly legal on paper. It's become the industry norm to throw you into an extreme block of duties only to then give you blocks of days off. I would much rather have a day off after each day of flying to recoup. The body needs it.

3 days in a row? That would be amazing; the norm in Europe LCC model is 5 or 6 in a row with max fdp days. Then you get 2/3 maybe 4 days off if you’re lucky where you’re not supposed to have a normal life but just rest and get ready for the next smash. It is unhealthy to wake up for days on end at 3/4 am or to go to sleep at 1 am after a late rotation.
Worst mistake of my professional career was to leave the corporate world to fly airliners; I was flying less than yearly half hours in executive compared to airlines and yes I was making half the money but my QoL was 100 times better, even with a non existent roster being on call and I was enjoying every flight. Moving back to corporate now, airlines (except for old school majors with great contracts) are a big no-no in terms of lifestyle.

[Surfacetoair]

I’ve long wondered whether the concept of Time Dilation has anything to do with that very specific type of tiredness one feels after a flight.

The attempt by your body or brain to account for and remedy the minuscule but measurable time lost after the high velocity travel may well fatigue it in a unique way.

Its noticeable enough as an inactive passenger, but must be worse for the flight crew who have to work as well.

I can’t find any research or mention of the effects of Time Dilation on ISS crew or astronauts. I suppose if it was a problem the effects would be felt far more severely by them than airline pilots?

[Smooth Airperator]

I feel as if this may have legs. I will speak to a friend in the biz to see what she knows. Astronauts are given months of special care and attention after they return in order to recoup. Of course mostly to recover physical strength following a zero G environment.

[iggy]

I’ve long wondered whether the concept of Time Dilation has anything to do with that very specific type of tiredness one feels after a flight.

The attempt by your body or brain to account for and remedy the minuscule but measurable time lost after the high velocity travel may well fatigue it in a unique way.

Its noticeable enough as an inactive passenger, but must be worse for the flight crew who have to work as well.

I can’t find any research or mention of the effects of Time Dilation on ISS crew or astronauts. I suppose if it was a problem the effects would be felt far more severely by them than airline pilots?

Either you are joking or you have watched Interstellar way too many times.

[SOPS]

3 days in a row? That would be amazing; the norm in Europe LCC model is 5 or 6 in a row with max fdp days. Then you get 2/3 maybe 4 days off if you’re lucky where you’re not supposed to have a normal life but just rest and get ready for the next smash. It is unhealthy to wake up for days on end at 3/4 am or to go to sleep at 1 am after a late rotation.
Worst mistake of my professional career was to leave the corporate world to fly airliners; I was flying less than yearly half hours in executive compared to airlines and yes I was making half the money but my QoL was 100 times better, even with a non existent roster being on call and I was enjoying every flight. Moving back to corporate now, airlines (except for old school majors with great contracts) are a big no-no in terms of lifestyle.

Thats exactly why, at 53, I realised that long haul flying was going to send me to an early grave. My roster as a train driver now is so much more controlled. Start at 4am … must be finished by 11.00 am. Driven a train for 5 hours? You must have a minimum of 30 minutes off. Longest shift 9 hours. Shortest shift 5.30 hours. Min rest between shifts 13 hours. And I have no jet lag and are home everyday.

[India Four Two]

I’ve long wondered whether the concept of Time Dilation has anything to do with that very specific type of tiredness one feels after a flight.

Unlikely :)

​​​​​​​To add a mere second to your age relative to friends and family on the ground, you'd have to fly west around the globe 3.7 million times!

https://www.realclearscience.com/blog/2021/07/15/time-traveling_on_an_airplane_one_of_the_cheapest_tests_of_relati vity_785017.html#!

[FullWings]

Several decades of LH has burnt out my body clock, I think. Occasionally I get a tired period during the middle of the day but most it’s about surviving nights out of bed. Strangely, I still can sleep 8-10hrs when given the opportunity but at work it can get a bit fragmented.

I have done 9-5 office jobs as well, and definitely felt a bit sleepy Friday afternoons, especially after a liquid lunch...

[CVividasku]

Thanks everybody for the input.
I can see two explanations listed : mental or physical.

I would rather opt for the mental explanation because this never happens when I'm sitting around all day long at home.
I fly for a very large operation with routes all over Europe (just on my type), but for personal, quality of life, reasons I signed up for an option with very few routes that I end up knowing by heart. It's a bit boring to fly always the same route. Even going everywhere in Europe it would just mainly be sit around waiting (at least for the flight).
I never regret my choice of working in the airline because it's still my dream job, the quality of life and the technical aspects suit me very well, but I just don't understand why the boredom has a physical expression.
On a typical day, I will try to be on my phone as much as possible between flights as I feel it helps me unwind, but maybe it's a wrong impression and I should try stopping.

Or, maybe the other explanation is a bit of mental pressure (even if bored, one has to be able to react if anything goes sideways), and/or the pressure (my airplane goes up to 5000 to 8000ft cabin altitude depending on the flight). The real boredom comes from flying 4-leg days. On the last day of a 4-5 day shift, sometimes I don't even remember if I did the departure briefing.

About the physical side, for context I am 28, rather slim but I don't work out or do sport really regularly. I still live a somewhat active lifestyle. For example just this week I spent two entire days out, walking, shopping, sightseeing.. I ran with my sister's dog. I often walk instead of taking the tube, even up to 2-4km depending on the time on my hands. I have a two story apartment and often forget things downstairs or upstairs... My girlfriends keep me very busy as well.
I try to avoid eating bull**** all the time (which is difficult because our colleagues bring us exactly that) but I'm not very keen on it so still end up for example ordering desert at a restaurant and I don't always turn it down at private dinners.
I put on some weight last year (1-2kg) when I decided to eat more and work out at the same time (to gain mass), part of it should be muscle and part of it fat.. I looked very slim and wanted to diminish that (my BMI is between 20 and 21).
My favourite drink at work is tea, I try to avoid hot water as I was told they don't clean the hot water tank, but still take some hot tea sometimes. The rest of the time, I put one tea bag and keep it in my glass with cold mineral water for 4-5 hours, only before 4pm. After that time I will tend to drink cold herbal tea (no caffeine).
I don't like coffee. I will sometimes ask for a coke which has the caffeine, but try to avoid it for sugar reasons, just like apple juice. Tomato juice is a drink of choice because no sugar.

Regarding sports, I could do more, I admit it could have some benefits. Last time I tried to motivate myself to do sports, it lasted for 3-4 months only, then I stopped for different reasons. I usually jog around my home, I have several loops between 1-3km. I bought some very good shoes for skydiving but I don't really intend on doing many more jumps (I did seven, until the first solo flight) because of it taking a lot of time, and the activity not being very rewarding for a beginner. I could use these shoes for jogging, which would help me greatly reduce the risk of any pain (which would come automatically if I jogged to much with bad shoes).
I also wanted to work out but I durably hurt my elbow and stopped immediately (I have a little pain in the elbow when doing pull ups, which I think is preventing me from lifting weights...) I should maybe go see a sports doctor to ask why the pain isn't going away and how to lift weight.

From a health point of view, is it better to work out or jog ?
From a fitness (esthetic) point of view, I think the best is to work out 100% first to gain mass then jog to eliminate the fat, but it's very demanding to do so at a good level. I also bought 4000€ of measure clothing, so it would be a bit stupid to put on a significant amount of weight (be it muscle or fat) and having to throw away the brand new suits and shirts...
But it seems to take a long term dedication that I will never have.

Finally, regarding my sleep patterns, I am a late owl. So when on my own, I will sleep typically from 3 to 12 (9 hours), and maybe from midnight to twelve if very tired from an early wakeup. When I have an early wakeup from home, I have trouble sleeping before midnight, so I typically end up sleeping 4-6 hours before my first day. If there is a second early, I will have much less trouble sleeping early and try to have at least 6 hours if there is no third early, 7 hours if there is. And 8 hours if there is a fourth early (even if it means going to sleep at 8pm without eating)
I don't work for a very demanding carrier, I work airline but no more than 13 days per month. I can't say I'm overbooked. If I worked 18 days (the maximum) I would make 30% more as well which would be very motivating.

[thetimesreader84]

It reads like you're doing all the right things. I wouldn't worry too much.

I found in most new "types" of flying, there was an adjustment period. For context I went night freight - Biz/GA - Airline over about a 10 year period and each time I found there were peaks & troughs in my mood & fatigue, almost exactly at the point you're at now, 8 - 16 months in. My theory is its a bit of your body & mind adapting to new conditions & partly a tension release after converting to a new type, new company etc. In my case it lasted about 6 months, then passed.

Keep doing what you're doing, ride it out, and I think you'll be fine. If it does get too much on particular days, use your companies FRMS and report fatigued.

[Uplinker]

Just some observations - I am getting the impression from your last post that maybe you are not allowing yourself enough down-time to relax. It sounds as if you have a very busy life ! Your working out with weights sounds busy to me. FWIW I do 30 press-ups and 50 sit-ups every week-day, and about a 10km run (jog) every week, sometimes twice a week. This keeps me nicely toned for seemingly not much effort. I do the daily exercises when I get up, and need no equipment for them, and no booking or gym time - and they only take me about 5 mins per day. That regime is quite gentle and not demanding, and is all I need to achieve a good body shape. I would definitely buy some proper running trainers though - you don't want to cause your joints any problems by running in the wrong footwear.

Your reliance on your phone to relax - I think that is probably having the opposite effect. They say that use of screens in the evening can make the body stay awake. I would try having time with no screens at all to relax properly. Leave your phone at home when you go out for a jog or a walk.
I personally find that when not at work; if I go the sleep much after 2300, I pass a threshold and my brain then stays awake - obviously a learned response to years of night flights, when my brain goes, "Oh, are we staying awake tonight? OK then." So maybe try going to sleep earlier in the evening and no screens beforehand. The blue light from the screens and the content you are looking at before trying to sleep might well be keeping your brain active and causing your sleep problems. A hot bath and a hot milky drink can help induce sleep.

Sitting around at home is not the same as sitting in an airliner cockpit - in the latter there is the constant low-level stress that tdracer spoke about, with moments of high stress during take-off and landing. Also the noise levels in a cockpit are very fatiguing. Interesting that train drivers do not operate for more than 5 hours before having a 30 minute break.

Regarding hot drinks - if the water has been boiled, it should be safe enough. Britons were less prone to health issues from bad water in the past, because they boiled their water to make tea. (Cold tea sounds horrible!).
I make healthy bread (with a machine) and healthy sandwiches to eat at work. Or salad in a Tupperware box - cut the salad up with kitchen scissors, which is quick and easy to prepare - and easy to eat with just a fork. I often put frozen cooked prawns in. The prawns act as ice to keep the salad cool in my bag, and when I am ready to eat the salad some hours later, the prawns have defrosted. That way, least I know what is in the food I eat.

Yes, you should see a sports physio to sort out your arm - might be able to get that under your airline health insurance.

[CVividasku]

It reads like you're doing all the right things. I wouldn't worry too much.

I found in most new "types" of flying, there was an adjustment period. For context I went night freight - Biz/GA - Airline over about a 10 year period and each time I found there were peaks & troughs in my mood & fatigue, almost exactly at the point you're at now, 8 - 16 months in. My theory is its a bit of your body & mind adapting to new conditions & partly a tension release after converting to a new type, new company etc. In my case it lasted about 6 months, then passed.

Keep doing what you're doing, ride it out, and I think you'll be fine. If it does get too much on particular days, use your companies FRMS and report fatigued.
Thanks.
I'm not too worried about it, it's tiring while I'm there but has little consequence apart from discomfort.
Cold tea sounds horrible!
It's actually very good ! I do this to help me drink a lot of water during a day of flying. I can easily drink the 1.5L bottle that we're provided with thanks to that.
It's not black tea, it's green tea with a flavor, and with cold water it gives a very slight taste

Thank you for your sports routine. It's true that push ups and sit ups are not so demanding to do, I should do them in the morning.