Why do most people feel drained after laying out in the sun? Not even doing anything active, just laying out.
I’m not saying it’sl ike this for everyone, but i feel this occasionally, and have heard others say the same.
Thanks.
Hell, it’s basically a thought problem.
For one, you are being heated. This leads to dehydration.
Two, your skin is being damaged by UV light, and your body must use more of its resources than normal to counteract the damage.
Unless you are able to photosynthesise, then yes, laying out in the sun will drain your energy reserves (at least as much as laying in the shade.
Have you tried laying out in the shade for an equal duration? do you still feel tired afterwards? (I suspect you might if you tried it)
The damaged caused by UV light takes several hours to be detected by the body. That is why your skin takes several hours to turn red. So I don’t buy this explanation to account for the initial feelings of being drained. It may explain the I-have-the-flu symptoms you get later in the day.
I buy the dehydration arguement
Another thing though is this, go lay down for a few hours during the middle of the day and do nothing. I do this on occassion and it almost always screws up my system so I feel groggy the rest of the day. No sunlight involved.
At this point, I must link to The Master’s article on oversleeping. The results are, sadly, inconclusive.
Not inconclusive for me…I am groggy after too much sleep and no study can say otherwise. The studies can only reach statistical conculsions that have little relevence to an individual.
The op says he/she is drained after sunbathing. I made no assertation that everybody feels this way, only that he/she should try my little test to see if it really the sun doing it or the extra laying around.
I gotta say that unless you have experienced this little phenomenon, you won’t know what I am asking. It’s not the same as laying down in the shade.
It could be dehyrdration, but it’s happened to me while drinking plenty of water.
More than likely it’s a combo of heat exposure and body dealing with damaged skin cells.
I was hoping that a doctor could come in and tell me about the body’s process of dealing with sun damage. The melanin rushing to the skin, ect.
jrootabega, being heated does not necessarily lead to dehydration. You made a little jump there buddy… By the way, specifically, what resources do mean?
mangetout, what energy reserves are you talking about? Carbohydrates, fat? Since when does lying around drain your energy? There is a difference between the sluggishness after being lazy and the drained feeling after laying out in the sun.
Umm… it’s lying out in the sun, not laying, unless you’re out there doing it with your girlfriend, in which case I can think of reasons why you might be tired afterward.
Just a guess:
Could it be that the increased surface temperature caused by the sunshine dillates the blood vessels, which would lead to lower blood pressure? That could cause light headedness and dizziness, n’est-pas?
[/guessing]
Any energy reserves your body might happen to posess; the human body doesn’t stop burning calories just because you are prostrate.
I’m talking about perceived energy getting drained, not your body biologically using energy. (I doubt lying out in the sun could burn more calories than lying in your bed, I could be wrong though) Your body going about it’s daily business does not make one feel drained, at least not me. The drained and very tired feeling after a day at the beach or pool is a stark contrast to the lazy day sluggish feeling.
Like I said, if you haven’t experienced this and noticed the feeling, it will be tough to relate to this question.
Perhaps the body slows it’s metabolism to avoid overheating.
I know what Fuel is talking about. I’ve felt the same on many occasions. Years ago when I was doing some Master swimming events outside, in between events I would lie out in the sun. When the next event came up, I was drained. I’ve also felt drained when at the beach, but the cold water revives me.
I learned not to be in the sun between swimming events, but I don’t do them now anyway. 
I don’t know the explanation. It’s not dehydration. I’ve been dehydrated without that feeling of being drained. So far noone has given a satisfactory explanation.
This question is still unsettled to my satisfaction. I did a number of searches and all I can find are those damn answer websites where 14 year olds give wild guesses without any source knowledge. (Actually the answers to this post haven’t been much different.) Sure, I could do the research myself, but the reason I searched for this question is because I’m on vacation, just spent the day out in the sun, and am now feeling drained and sluggish. So I’m not going to do it myself because I’m on vacation and feeling lazy.
But I will list the theories that I found and hopefully someone can shed some real science on the matter:
- Dehydration (but I don’t feel dehydrated…)
- Body is repairing skin damage (but I cover myself in sunscreen, and my skin appears completely undamaged by the sun, yet I still feel sluggish)
- Body is attempting to regulate your temperature (keep you cool) by discouraging physical activity.
- Warmth makes you “comfortable,” and comfort leads to sleepiness (this is definitely unconvincing to me)
- Heat causes your blood vessels to expand, which in turn drops blood pressure. (would have to hear this from a doctor before I believed it)
- Some craziness about your pupils being dilated tiny for so long that it causes headaches, eye strain, and fatigue?
- Something about UV rays, irrespective of skin damage, and their effect on the body?
- One guy claims that fatigue is a symptom of Vitamin D overdose.
- And the award for the answer I find hardest to believe: “The weight applied to your chest by the heavy barometric pressure which usually comes with clear weather may have something to do with it.”
Ok, I’m sure there are other crazy theories out there, but I’ve got a beautiful tropical sunset to go watch.
My point is that there is clearly so much wild speculation out there that this deserves a well-reasoned answer. Good luck!
Both melanin and Vitamin D are produced in the skin, they don’t rush there from anywhere.
Does it really? I know its disappointing when you come to the SDMB and see people trying WAGs but …
The question was, “Sun drains energy?” That’s impossible, our sun uses fusion power to provide energy, and thermodynam…
Oh, wait, this wasn’t an astrophysics question. It’s a stated opinion, “Most people feel drained laying out in the sun.” I don’t feel drained. And that’s my opinion. I feel the same lying out in the sun as I do under the covers on a winters day, warm and lazy." I think that’s as good of an opinion as the initial supposition that started this thread. And miles better than the title.
Let’s spend another 9 years thinking about your list.
I blame the sun zombies.
I’ve often described myself as solar powered because on cloudy days I don’t want to do anything but if it’s sunny out, I feel like there’s nothing I can’t do.
Let’s see, you are lying somewhere warm and comfortable doing nothing and feel a bit tired after you stand up. Sounds like people go into a slumber/pre-sleep state to me.