air consumption and athletes

[EBdiver]

I always thought that engaging in some sort of aerobic activity on a regular basis improved air consumption, but a diver-friend of mine said that it was the other way around. He's an athlete, and sucks up his air pretty quick. On one dive, he was diving with a Steel 80 and was running low on air. I came up 10 minutes later with 1500psi (Steel 72). Bear in mind that I'm not exactly tall, but I work out at least an hour a day, 6 days a week. Here's the explanation he gave:

People who exercise/athletes obviously do a lot of aerobic activity. Aerobic means exercise with oxygen, so the longer you exercise, the more oxygen you consume. According to him, this has an effect on our lungs. He says the lungs of athletes are bigger than non-athletes as a result of all the aerobic activity they take part in. So in turn, this has an effect on the air consumption rate at depth.

Is there any truth to this? I was very iffy when he said that.

Any thoughts?

 

[SPEEDSTER]

There are several ways to look at this,

1. Take 2 people, one an athlete, the other an average joe who isn't fat, but doesn't do any cardio. Put them at the base of one flight of stairs and have them run up it once. Check their breathing rate. The athlete will be breathing harder than Joe because he/she has trained their body to respond quickly to physical exertion. The flip side is that the athlete can do this repeatedly, whereas Joe will become exhausted quickly.

-or-

2. The athlete is more accostomed to having access to an inexhaustible supply of air and their lungs use it like a lamborghini doing 140 up a mountainside.

Personally, I would consider myself an athlete. My SAC rates are WAY better than anyone else I dive with on a regular basis, so I think its a combination of the above 2- an athlete will begin to use more air as needed quicker, but will plateau at a lower sac rate while working than the avg Joe.

whaadya think?

-Mike

 

[sillygrendel]

I'm sure being in decent aerobic activity helps air consumption.

Training for climbing can be a pretty tricky proposition because you tend to get very concerned with mass/strength ratio.

There are two main types of muscle training - hypertrophy and maximum recruitment training.

Hypertrophy training build larger muscles but hurts maximum recruitment.
Maximum recruitment training makes the muscles slightly smaller but allows you to use 100% of your muscle fibers.

For this reason Hypertrophy training (when needed) in climbing is usually follwed by MR training.

Why is this relevant? Having a very high MR is kind of a double edged sword. You have much stronger, smaller muscles. But you also have the capability to burn much more energy with a given contraction. If you're not relaxed and in control of your muscles, you'll get screwed.

Comfort in the water is probably a pretty large factor though. What I'm describing could come into play with certain body types however.

 

[MASS-Diver]

Your friend should get a clue. A person who trains with endurance exersise will drastically improve thier air consupmtion.

A fit person's heart is able to expel much more blood per beat (stroke volume) as a result they can pump more blood with less beats (as opposed to a unfit person whose heart has to beat many times to equal the same cardiac out-put). As a result the fit persons body is able to operate longer before engery and O2 stores are used up.

Also endurance exerise leads to more vascularization and changes in muscles that allows them to perform for longer under strain. (more blood vessels bring more O2 allowing the muscle to function longer beofre failing).

You friend doesn't realize that it's Co2 that creates the urge to breathe and regulates breathing rate, not O2. A fit person's body due to better vascularization (for example) can exhange O2 and Co2 more efficiently and therefore less Co2 builds up on the blood and less "huffing and puffing" takes place.

Have your buddy pick up and A+P book or any biology book some time. And have him check out world class divers like the WKKP guys and see what they think of his theory. This is the problem with just trying to reason things out on your own when you have no background in the subject: you come up with these bizarre ideas that make sense only to you.

 

[SubMariner]

Frequently air consumption is not just a function of how physicially fit a person is, but in fact relies on several factors:

1) HOW they breathe. Most people tend to take shallow breaths, only using about the top 1/3 of their lungs. However, people who have received voice training or learned to play a wind instrument use more of their lungs. They take larger, longer, more full breaths and have better breath control.

2) Experience. People that are new to the sport tend to breathe more rapidly and shallower than their more experienced dive buddies. A relaxed breathing pattern is best.

3) Level of physical fitness. This has already been discussed. However, it is the level of aerobic fitnes that counts, not just strength or endurance.

4) Size. Yes, it does matter. (But not the way you think ) The BMR (Basal Metabolic Rate) for a smaller person is lower than that of a larger person.

5) Level of u/w activity. Ask any photographer how much air they use and how long they were down taking pictures. I think you'll be astounded at how little air they use vs. their friends who were off setting speed records for sightseeing.

So... it's best to be a small person who used to play the clarinet, has a good level of aerobic fitness, is an experienced diver and likes to take pictures. :shades:

~SubMariner~

 

[Zagnut]

..trying to make an excuse for his rate of consumtion. He has it backwards. As has already been said, body size and amount of comfort and lack of focusing on optimal breathing underwater probably has more to do with his faster consumption. Your lungs aren't going to "grow" because you start working out. If that were true can you imagine how HUGE Lance Armstrong's (I think that's his name..the bicycle guy that beat cancer and keeps winning all those races in Europe)..can you imagine how HUGE his lungs would be...he would be all barrell chested to make room for those "huge" lungs!

 

[MASS-Diver]

I just wanted to add that agree that lots of factors go into air consumpation, a marathon runner is going to have poor consumption when they first start diving, but, my point in regard to this thread is if you start running it will improve you air consumption big time. This is espically true after you get some experince and your consumption seem to level off.

Again, running build up your heart letting it pump more blood per beat which is results in you achieveing the same cardiac output with fewer beats, this is more efficent. A person who is in shape may have a resting pulse as low as 50beats per minute (take yours now and see what it is) while some who is not fit may be closer to an hundred, so when that out of shape person starts swimming there heart rate goes crazy and there body needs all kinds of O2 to keep up so they start sucking that tank dry. This is just one benfit of being in shape for air consumption, the increased vascualrization is also very helpful and better perfusion means better off gasing.

I can't even adress the comment about your lungs 'growing' they aren't a muscle.....

 

[scorpiofish]

but a diver-friend of mine said that it was the other way around. He's an athlete, and sucks up his air pretty quick

I'll be your test subject.

I dive year round. My conditioning varies quite a bit. When I am at my fittest, my air consumption rate goes down. The less exertion, the less difference.

While my SAC rates may vary tremendously depending on the situation, in all similar circumstances, I use less air when I am fitter.

Some athletic new divers go through air more quickly. Why? Because they are more fit, they are prone to move more because it is easier for them.

The rest has already been said by others.

 

[Amanda]

Just my two cents...

I think I agree that one person needs to be physically fit AND an experienced diver tp lower his/her air consumption.

I'm a not an athlete, but I do keep myself in shape, and I often exercise on air consumption to improve it. Result is : (talking in Bars... don't know haw many PSIs it is... )

-I never go out of a dive with less than, at least 100 bars.
-I've done 1 hour dives in 15/20 meters depth, and only using 100 bars...

So I think diving experience counts more than just physical training. It is a state of mind too, you need to be relaxed and confident u/w ! The best athlete of the world will suck his tank dry in less than 10 minutes if he's not comfy down there...

*edit : forgot to mention I play saxophone if it matters... *

 

[John C. Ratliff]

You can take some of the fittest athletes in the country, put them into scuba, and they will sometimes drain the tank very quickly. In addition to the fittness mentioned above, how a person dives is very important to air consumption.

If a person is at ease in the water, and relaxed, then air consumption will go down, way down. That is because he or she is only using the muscles needed for propulsion, breathing, etc., and not loosing energy to muscular actions which have nothing to do with swimming. People who tense muscles will use more oxygen, because these tensed muscles are contracting. They aren't doing anything else, but they do use oxygen. A relaxed person, on the other hand, will not unduely use oxygen because only the needed muscles are working.

The person's equipment configuration will influence oxygen consumption, as will his or her swimming technique. The more efficiently you move through the water, the less oxygen you use. If you are swimming with someone who is neutrally buoyant, and you are negative by 5 pounds, that turns your body so that you are now planing through the water, with greater air consumption to stay with the person who is correctly oriented and neutrally buoyant.

Given equal situations, the more fit person will probably consume less air than the less fit person. I say probably, because if the more fit person has an ill-fitting wet suit on, and you are dry and relaxed while (s)he is becoming hypothermic, then you will consume less air because you are not shivering to stay warm (which takes oxygen too). Fat does have its advantages, especially in cold-water diving. So either be a bit heavier in a colder suit, or get a warmer, better protecting suit.

SeaRat