Tired after diving

[Moonfuzzy]

Bubbles, affecting circulation, histamine reactions, gas diffusion in your lungs.
Dehydration
Core temp changes

[midway]

I think it's a very good question. As to DAN having answers, it doesn't hurt to check with them but I'd be surprised if they have definitive answers. Diving physiology is still iffy as a science. The various deco models are principally physics models. Tissue on- off-gasing, bubble formation, etc. How bubbles affect physiology, beyond the coarse effects (e.g., embolism, nerve conductance, some immune reaction) is still very much open.

I don't feel super tired, it does not feel like anything is wrong or abnormal, I am just curious as to why diving would make you feel tired at all since there is no real effort involved in swimming underwater.
On dives like the El Toro project we had 2.5k of scootering, then 2.5 hours of lugging tanks over a dry cave and then swimming for another 4000ft laying line, there I was tired too but nothing abnormal either, the dry cave part was hard but the scootering and swimming was not really any big effort.
When I do shallow 1.5 to 2 hour cave dives I feel as tired as if I went surfing, I don't feel bad at all, just tired in a good way.
My theory is that even though I don't get cold much, my body to maintain a constant temperature has to burn a lot of calories for the duration of the dive and that is what makes me feel tired.
My heart is ok, I had it checked for everything prior to my knee surgery at NYU.
I am just curious, DAN said that diving for two hours is roughly the physical equivalent of jogging for 20-25 minutes but could not explain why exactly.

[Tucker]

BLUF - I've always thought being tired after diving is normal.

I've always feel tired after a full day of diving. I've often chalked it up to the early morning starts or off gassing. I've never though of it as abnormal. I'm a little surprised to see everyone suggest that it is "NOT" normal to be tired after a day of diving. I will have to keep track of how I feel after dives and see if it changes with mixes, temperature, level of effort, and time of day. I think I know exactly what phillip1 is talking about. My wife and I had a talk during our last vacation. I would come back from a full day of diving and just want to take a nap for an hour or two. She was hoping to go out on the town right after I got back and I just wanted to lay down for a bit. I'm 34 and in good shape (run 3x a week, and score over 260 on my Army PT tests).

Tucker

[Tegg]

Ascent rate in the shallows.

I had similar issues early in my diving and have since learned to ascend the last 30ft much more slowly and the issue went away and I have only experienced it when I don't follow this.

Just a thought...

[JE]

It is Summer in Florida ...what do you expect ? the nite before... eat a good pizza somewhere & have a beer before you go diving the next day & you will not feel tired ! Build up your calories to give you more energy & you will not feel tired when you go diving.....give yourself at least 8 hours though before you dive !

{ps: I was not going to post anymore cause certain jerk offs where bad mouthing me...but wth...i can at least pass on my experiences}{lest you call me a troll too Tegg !}

[Nitrogenius]

BLUF - I've always thought being tired after diving is normal.

I've always feel tired after a full day of diving. I've often chalked it up to the early morning starts or off gassing. I've never though of it as abnormal. I'm a little surprised to see everyone suggest that it is "NOT" normal to be tired after a day of diving.

+1
Always have been tired, always will be. No matter if it is a 1,5 hr very shallow cave dive or a 80m 120 min RT Ocean Dive or also in the early days a 45 Min 12 m reef rec dive..
Never thought much of it and I am also surprised at some reactions.


No PFO here (already checked for other reasons) and always very well hydrated (would be a fool not to take care of that as app. 90% of DCS relates to not proper Hydration)..


I do notice quite a difference when using nitrox on dives where air would suffice..


Can't compare for the real deco profiles for obvious reasons..


Well a Little as well.. I have a couple of technical deep air dives (with Nitrox + O2 for deco) where i also used to be super tired.. much less on the hi He Breather dives..

[phillip1]

I don't think it is abnormal at all and agree with you, I think it is perfectly normal to feel tired after a day of diving. I mean if I have to walk for hours in the jungle or do some dry caving to access the water then it is easy to understand, and I would deb tired even without diving. However there is something that we all do when diving that makes it physically tiring, I just cat really figure it out.
Maybe frog kicking slowly in the pool with a snorkel on the surface in full gear would be tiring too after an hour or more.
I never feel bad after diving and the tired I feel is a good tired and I alway go to bed early after a day of diving, which is a good thing anyway.

[loquat149]

You think DIVING makes you tired? Try reading all 98 posts of this thread and see what TIRED feels like.

http://www.scubaboard.com/forums/sid...2-1-sms75.html

Dave

[Aotus]

I found this article posted by DAN. In it, one person explains that tiredness after a dive may be related to pressure changes in the heart in response to immersion. He mentions that a wetsuit may factor into this pressure, I wonder how a drysuit would be different...is the gas in the drysuit creating enough pressure inside the suit to pass on the pressure changes to your body? I would guess so... Here's the relevant segment:

Neal Pollock PhD: Many people do not fully appreciate the physiological impact of being immersed in water. An immediate response to the hydrostatic pressure is that a substantial amount of blood normally remaining in the capacitance vessels (veins) of the legs is pushed to the central volume (in the chest). A well-known study of this effect found that an average of 700 mL of blood is pushed to the heart during the resting phase of the cardiac cycle. The heart is stretched by the increased blood volume and responds immediately by contracting harder and then, over a short period, by suppressing certain hormones to promote increased fluid elimination through the kidneys. This is a healthy response to the physiological perception of the presence of excess fluid volume. Practically, this is why people have to urinate even after fairly short periods of immersion.

After leaving the water, the diver may experience an immediate drop in the volume of blood returning to the heart. I specifically said "may" because a constricting wetsuit may shift some of the blood to the chest even without immersion. Postdive (or post-wetsuit removal), the diver will experience a decline in the central blood volume and blood pressure. The effect exceeds the simple loss of hydrostatic pressure because the body has been actively reducing the fluid volume during the diving (or wetsuit-wearing) period. Effectively, this set of events likely explains a substantial portion of the normal postdive tiredness. Most important, fatigue is due to immersion, independent of depth and decompression stress.

[gschaut]

The "tired" feeling I get after a long, deep dive feels almost the same as the "tired" feeling I get on top of Pikes Peak (14,000'). I always thought it was a reaction to going from 1.0 ATM O2 (at depth & on deco) to .21 (surface air). Any thoughts?