TSandM provides excellent advice - and the concept of underwater breathing being similar to yoga or meditation (or martial arts) is advice I have given to divers for years - an efficient gas exchange in the lungs means you build up less CO2 and therefore need to breathe less.
The faster you breathe, the more you will breathe - because as TSandM states - you're basically rebreathing dead air and you also create turbulence in the trachea which makes the gas exchange even more inefficient. Furthermore, if you are correctly weighted, then rapid breathing tends to make divers remain permanently positively buoyant with respect to the effect of the air in their lungs - and poor buoyancy control is a big hitter when it comes to air consumption. If you are over-weighted, you will use more air to maintain your position in the water, and if you are underweighted, you will work harder to keep yourself submerged, which will significantly affect your air consumption.
The slower you breathe, the less you will need to breathe, because you are eliminating more CO2 more efficently. I have found over the years that if the diver is using good technique and is correctly weighted, then personal fitness does not necessarily have a huge impact on air consumption. I dived with an olympic trained athlete last year and he sucked his tank dry in 35 minutes.
What I generally teach is a regular 5 second in, 5 second out breathing pattern which yes, I know is not necessarily the best, but it's quite easy to maintain on an easy recreational dive. Sip the air from the regulator slowly, rather than gulping - and this is a horrible analogy to use but it's a bit like savouring a good smoke. When people ask me why so many instructors smoke, I often joke that it helps our air consumption because we are practicing our breathing technique all the time! (Note for the anti-smoking lobby - that's a joke - please do not take up smoking!!)
Buoyancy control and efficient finning technique are the key - and then you can work with slowing down the breathing. You will find that underwater nerves will actually be calmed by getting these correct.
Hope that helps
C.
The faster you breathe, the more you will breathe - because as TSandM states - you're basically rebreathing dead air and you also create turbulence in the trachea which makes the gas exchange even more inefficient. Furthermore, if you are correctly weighted, then rapid breathing tends to make divers remain permanently positively buoyant with respect to the effect of the air in their lungs - and poor buoyancy control is a big hitter when it comes to air consumption. If you are over-weighted, you will use more air to maintain your position in the water, and if you are underweighted, you will work harder to keep yourself submerged, which will significantly affect your air consumption.
The slower you breathe, the less you will need to breathe, because you are eliminating more CO2 more efficently. I have found over the years that if the diver is using good technique and is correctly weighted, then personal fitness does not necessarily have a huge impact on air consumption. I dived with an olympic trained athlete last year and he sucked his tank dry in 35 minutes.
What I generally teach is a regular 5 second in, 5 second out breathing pattern which yes, I know is not necessarily the best, but it's quite easy to maintain on an easy recreational dive. Sip the air from the regulator slowly, rather than gulping - and this is a horrible analogy to use but it's a bit like savouring a good smoke. When people ask me why so many instructors smoke, I often joke that it helps our air consumption because we are practicing our breathing technique all the time! (Note for the anti-smoking lobby - that's a joke - please do not take up smoking!!)
Buoyancy control and efficient finning technique are the key - and then you can work with slowing down the breathing. You will find that underwater nerves will actually be calmed by getting these correct.
Hope that helps
C.