physiology Q1> why am i tired after diving ?

[Salt]

Got about 70 dives under my belt now. Done a bunch in the last 2 to 3 weeks.

I am usually pretty tired after diving. I feel sleepy. lethargic. sometimes a little lightheaded. it goes away eventually. Most often with two tank dives but also I think, to a lesser degree, with one tank dives. I have even dozed off during my surface interval.

lots of factors at play here. I used to think this might have had to do with not getting enough sleep and getting up early but i don't think so anymore. I have had enough opportunity to observe the phenomenon over the last two weeks with different amounts of sleep and afternoon dives instead of morning dives.

I suspect it has something to do with breathing in the air mixture under pressure for 55 minutes or so. And I am sure depth factors in as well. This is why people use nitrox, right?

I have heard several other divers comment on feeling tired as well.

Can someone give me a good explanation for this? and any ways to alleviate it?

 

[OMANDIVER]

Got about 70 dives under my belt now. Done a bunch in the last 2 to 3 weeks.

I am usually pretty tired after diving. I feel sleepy. lethargic. sometimes a little lightheaded. it goes away eventually. Most often with two tank dives but also I think, to a lesser degree, with one tank dives. I have even dozed off during my surface interval.

lots of factors at play here. I used to think this might have had to do with not getting enough sleep and getting up early but i don't think so anymore. I have had enough opportunity to observe the phenomenon over the last two weeks with different amounts of sleep and afternoon dives instead of morning dives.

I suspect it has something to do with breathing in the air mixture under pressure for 55 minutes or so. And I am sure depth factors in as well. This is why people use nitrox, right?



I have heard several other divers comment on feeling tired as well.

Can someone give me a good explanation for this? and any ways to alleviate it?

Having a look at the theory and background behind Deep Stops/Pyle Stops may be useful.

 

[kensuf]

Got about 70 dives under my belt now. Done a bunch in the last 2 to 3 weeks.

I am usually pretty tired after diving. I feel sleepy. lethargic. sometimes a little lightheaded. it goes away eventually. Most often with two tank dives but also I think, to a lesser degree, with one tank dives. I have even dozed off during my surface interval.

lots of factors at play here. I used to think this might have had to do with not getting enough sleep and getting up early but i don't think so anymore. I have had enough opportunity to observe the phenomenon over the last two weeks with different amounts of sleep and afternoon dives instead of morning dives.

I suspect it has something to do with breathing in the air mixture under pressure for 55 minutes or so. And I am sure depth factors in as well. This is why people use nitrox, right?

I have heard several other divers comment on feeling tired as well.

Can someone give me a good explanation for this? and any ways to alleviate it?

Obviously nitrogen loading and pushing the limits of your computer can contribute, but there are many other factors that can contribute to being tired. Hypothermia (how cold is the water you're diving in, what thermal protection are you wearing?), workload (are you working hard in strong currents?), your physical conditioning (cardiovascular fitness, strength, etc), mental fatigue (what are you doing on your dives, is it causing you to concentrate a lot?), dehydration (what are you hydrating with, remember compressed gas is very dry), and more.

Let's start with the easy stuff: what are your dive profiles like? How deep? How long? What is temperature and current like? What are you doing on your dives?

 

[knotical]

My speculation about feeling tired after scuba has been that it’s largely a matter of losing energy (in the form of heat) to the water around us. I’ve always felt at least somewhat tired after scuba, but also after just snorkeling or swimming. Wearing a hood, even in the tropics, seems to reduce this.

The lightheadedness might be a totally different animal and could be related to your middle ear.

There are also occasional comments that tiredness can be a subclinical symptom of DCS. This carries more credence if you notice it more on dives pushing the NDLs than on those that don’t.

 

[Donnah]

I'm not sleepy after dives, but 3 dives a day and I'm in bed by 8:30. In my family, we refer to that time as "Diver's Bedtime." That's true for the people I dive with, but I do dive with "senior divers."

 

[Salt]

currently on vacation diving in the Caribbean. shorty wetsuit. still feel a little cold underwater, especially on the 2nd dive. I am a pretty thin guy without a lot of natural insulation.

Doesn't feel like I am exerting myself much. Just kicking a long. Maintaining slow and steady breaths.

Drank water the night before and in the morning and during surface interval.

I don't have a dive computer, just following the guide. Dive profiles are on the first dive deep to start, maybe 70 to 100 feet, then coming up to around 30 feet for the second half. Second dive is usually shallower 50ish then going to 30.

It happens on a wide variety of dives.

One time it was really bad. I had stayed up the night before, had a few beers, got up early, and went down to 90 feet first dive. afterwards I was extremely lethargic, my thinking was foggy, and I slept half the day away. It went away after about 24 hours but it did give me some concern that I was suffering from some mild decompression illness.

A lot of different factors potentially at play here. but even when I am taking care of my body, getting enough sleep, no alcohol, staying hydrated, etc., a two tank dive will make me feel a little sleepy.

---------- Post added May 26th, 2014 at 12:35 PM ----------

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Interesting about the inner ear. I had a head injury many years ago that damaged my inner ear. It can sometimes give me dizzy / lightheaded feelings if I shake my head up. hadn't considered that before.

Also hadn't considered heat loss could make me tired since i am diving in the Caribbean. I'll try a hood and see if that makes any difference. I notice a lot of the Dive Guides wear hoods.

What does subclinical in subclinical DCS mean? I am not familiar with the medical jargon. Does that just mean mild symptoms?

 

[dumpsterDiver]

I think it most definitely has to do with "Nitrogen loading Stress"... Not sure if that is a real term, but we found this out in Cozumel many years ago.. Warm water, super easy diving, just drifting along, no rough seas, easy boat ride, no carrying heavy tanks to or from the boat, yet after two dives which approach the deco limit, we were always tired. There is no other explanation in my mind.

Of course cold and rough water and exertion will make things worse, but I have no doubt it is simply from the depth and N2 loading. I also think that your body will adapt to it, to some degree if you dive frequently.

On days where I would do 4-6 dives (in other locations) where I would approach or exceed the no-deco limit, it was almost a given that I would need a 20 minute nap on surface intervals. If the water is cold or cool, I find it tremendously helpful to take a nap, wrapped in a sleeping bag. 20-30 minutes wrapped up, dozing off a little and waking up sweating allows me to recover almost completely.

I also do freediving which involves much more swimming, exertion and effort, but in general, it does not make me as tired as scuba diving.. unless I push the freediving really hard.. for me that would be dozens of dives per day past 50 ft depth.. but that could end up being nitrogen stress as well, i suppose.

 

[kensuf]

Guys, even if the water temp is 81-82F, your body is going to work to maintain homeostasis when underwater. I am more inclined to believe its mild hypothermia rather than subclinical DCS.

Salt, how long are these dives? By "still feel a little cold underwater" what do you mean exactly? Goosebumps? Blue lips? Shivering?

FWIW, I tend to get cold on weeklong dive trips in the Caribbean. Typically I do 2-3 dives per day of 45-70 minutes each on those trips. I also wind up hungry as hell from the hypothermia. I usually wear an old 3mm suit that is badly crushed and more like a 1.5mm suit to help offset this, but I can still get cold in 82F water when I am barely working underwater.

 

[reghunnicutt]

Interesting discussion. I about drifted off on surface intervals boat diving in February on St Croix. I figured it was conditioning since I was still building strength from a back surgery the previous May. I dove the local quarry yesterday and was better but darn tired after two dives. I'll soon be 58. All dives on air.

I'm diving off shore in Georgia Sunday and am going to use EAN 36 and see how I feel.


Reggie in Midland, NC

 

[spectrum]

I think you are answering your own question.....

"shorty wetsuit. still feel a little cold underwater, especially on the 2nd dive" is a red flag. Depletion of thermal energy will suck the vitality right out of you. Sometimes called silent hypothermia it can leave you indifferent about even diving by the end of a vacation. The cure is simple, more thermal protection. Something on your head, a full suit, a vest a heavier suit and for some even an appropriate drysuit. Also note that good fit is implied for any of these to be of value.

Also how are your final ascents, and do you yo-yo? Making your way to the surface equisitely slow can do wonders for reducing your body stress. Doing stops is great but after the stop come up very slowly. Also if you are gopher diving, coming up for bearings checks or other reasons each of those surfacings is making maters worse. Try to minimize surfacings and do them very slowly. I can recall two times getting home from local dives and being profoundly tired. In both cases we had been up and down several times from 30' or so and had not been so elegant in doing so.. This is sometimes referred to as sub clinical DCS. Those needless deco cycles froth your blood up in a small way and you won't fire on all cylinders until things calm down.

If you are assaulting your body for consecutive days with cold and blood gas you expect to feel like crap.

If you are on a dive vacation following the dive masters computer does not represent your day to day activity and is pretty bogus.

Even though science has yet to support it, common sense and masses of experience indicate that using nitrox will be of benefit too.

Pete