Is there a reason you get so tired from scuba diving?
The main reason why individuals who participate in recreational diving experience exhaustion or physical fatigue is because of an accumulation of carbon dioxide (CO2) which can be regarded as an acid at high concentrations.
The buildup of CO2 in the bloodstream causes respiratory alkalosis which is translated to the body as over-breathing or hyperventilation. This over-breathing, while at depth, can be considered an adaptation to the high availability of oxygen (O2) at lower atmospheric pressures. As you go deeper, there is less O2 per unit volume so our bodies overcompensate by breathing more air.
This does not only occur underwater but can happen on land as well when you have a very low partial pressure of oxygen while breathing, such as at 14,000 ft altitude
Divers are generally armed with tanks filled with air which contains 21% oxygen and 78% nitrogen. Oxygen levels may become very high after a long period of time within this breathing mixture due to reduced partial pressure affecting every liter of gas that comes into contact with your bloodstream.
What is decompression stress?
Another common cause of fatigue and exhaustion from scuba diving is decompression stress. Why might that be? Some people are more affected than others due to a variety of factors, e.g. the rate they get rid of CO2 via their lungs could vary per individual so too could their blood and tissue levels of oxygen and nitrogen; not everyone will experience the same level of susceptibility to pressure changes either.
When your body makes a dramatic change in depth, it undergoes acute pressure changes. Your body’s gas exchange system (lungs) works hard to equalize the pressure which can lead to over-breathing or hyperventilation-like symptoms as well as expansion of our intravascular spaces or increased blood volume in order to release the extra pressure.
We may feel more tired because of this and as a result, breathing more air at depth in order to compensate for higher O2 levels will no doubt make us feel fatigued but once we ascend again to shallower depths, our bodies remove CO2 from the blood and breath it out easier so our over-breathing adapts by slowing down then returning to normal respiration
Decompression stress can be considered an adaptation rather than something that might cause great harm, which is good news for recreational divers!
How can you avoid decompression stress when scuba diving?
- Use an accurate dive computer to determine your planned depth and time limits. A dive watch or dive timer which is reliable should ideally have been tested before use with the same model as what you intend to buy. Diving tables, though they do not calculate depth and time limits precisely like computers will nevertheless provide you with a guideline for your planned dive at that given time – plan ahead!
- Do not exceed the depth limit set by your computer or divers tables. Some dives allow animals into their habitat in order to create more protection from predators so make sure you don’t disturb such life forms. Plan enough bottom time in order to minimize ascents and descents
- Plan your dive time underwater carefully to avoid exceeding the maximum surface interval recommended. The best way to achieve this is when you are on a boat, you can determine how long you are going to be diving for then simply subtract the surface interval (usually around 1 hour) from your total dive time as we do not want to surpass it!
Why? Because once our bodies have been pressurized by depth, it will take some time in order to qualify for another dive as our bodies work hard to return back to normal.
This means we must wait at least 12 hours or more depending on which organization was responsible for the training and certification of that individual diver. We should also avoid repetitive dives because it puts us at risk of DCS (decompression sickness)