Caloric use while free diving

[Dr. Hawk]

Hey all,

I do cardio work often, and I enjoy doing some basic free-diving in the pool to top it off and relax. I do notice however that I still get a good workout from my dynamic dives. I was wondering aprox how many calories my body is using? I usually spend 2-3 hours each day swimming, 1-2 hours being dynamic and the last hour static. Rough numbers but anyone got a rough figure? mostly just curious. Thanks

Hawk

 

[Johan Andersson]

It is difficult to give you a precise number.

The energy cost of swimming (including fin swimming) is highly variable among individuals. The variation is about 25%. This is so because swimming is more technique dependent, which is not the case for walking or running to the same extent.

Also, the energy cost of swimming increases exponentially as a function of velocity (i.e., your energy expenditure will depend on your swimming speed - the faster you go, the more energy will be needed to move a certain distance).

There are also other factors to consider.

This said, I remember a study in which fin swimming was shown to result in an energy cost of swimming of about 4-7 J/(m*kg) over a range of speeds from 0.7-1.1 m/s.

/Johan

 

[Dr. Hawk]

Nice formula,

I'm not the best at math, but I think I can ballpark figure now, thanks!

 

[chrismar]

Won't that be significantly affected by the metabolic pathway? It was my understanding that anaerobic versus aerobic was about an order of magnitude less efficient?

 

[Johan Andersson]

chrismar, I don't know if I understood your question right, but I'll try to give an answer.

To maintain a certain speed, you need a certain amount of energy (ATP). And yes, aerobic metabolism is more efficient than anaerobic metabolism with regard to harvesting the energy stored in glucose. You get 2 mol ATP per 1 mol glucose using anaerobic metabolism (glycolysis) vs a theoretical 38 mol ATP per 1 mol glucose when using aerobic metabolism (2 from glycolysis, 2 from the Krebs cycle, and about 34 from the electron transport system). (Note: Theoretical, because the cellular respiration is not 100% efficient, and thus the ATP-yield is slightly lower than 38:1 for aerobic metabolism - the maximum is closer to 28-30 ATP molecules.)

Using either aerobic or anaerobic metabolism doesn't mean you change the energy requirement for maintaining your speed, only how much ATP you get from each mole of glucose. Thus, assuming a certain energy requirement, you need more glucose when using anaerobic metabolism, but this is so because in anaerobic metabolism you are only able to release a smaller amount of the energy which is in the glucose molecule compared to when you metabolize the glucose aerobically. The remaining energy is not "lost", but will be found in the lactate molecule which is formed from the pyruvate that is the end product of glycolysis. The energy in lactate can be used when oxygen is once again available (and aerobic metabolism dominates).

The energy you use will not differ between aerobic/anaerobic metabolism, but you will need to have a high anaerobic rate to produce the same number of ATP:s, meaning that you will fatigue faster.

Don't know if this made any sense...?

/Johan

 

[chrismar]

Thanks Johan, that did make sense. I realise that the actual energy required to propel would be the same no matter where it came from and that the energy pathway in anaerobic work was different, but I didn't know that the energy 'lost' from the glucose was reclaimed from the lactate. I thought that it was lost as waste products, thus ending up as much more energy intensive.

This is quite different from what I thought and will probably change how I think about diet & training for freediving. Thank you.

 

[Simos]

Yes interesting info - is this related to the Cori cycle Johan? [ame="http://en.wikipedia.org/wiki/Cori_cycle"]Cori cycle - Wikipedia, the free encyclopedia@@AMEPARAM@@/wiki/File:Cori_Cycle.SVG" class="image" title="Cori cycle"><img alt="Cori cycle" src="http://upload.wikimedia.org/wikipedia/commons/thumb/8/8a/Cori_Cycle.SVG/460px-Cori_Cycle.SVG.png"@@AMEPARAM@@commons/thumb/8/8a/Cori_Cycle.SVG/460px-Cori_Cycle.SVG.png[/ame]

 

[Andrew the fish]

gentlemen, how about energy loss for temperature control? I know for the fact, when I swim in cold waters I lose weight.

 

[Johan Andersson]

Yes interesting info - is this related to the Cori cycle Johan?

Yes, that is one way to take care of the lactate. Another example is using the lactate (converting it back to pyruvate) in the muscles in which it was formed, once oxygen is available.

 

[Johan Andersson]

gentlemen, how about energy loss for temperature control? I know for the fact, when I swim in cold waters I lose weight.

Sure, in cold water you have a higher metabolic rate overall, in order to maintain body temperature.

 

[Simos]

Sure, in cold water you have a higher metabolic rate overall, in order to maintain body temperature.

Hmmm I don't think you burn many calories when you dive in cold water because of the bacon sandwich and chips after (did I mention the hot chocolate too) :friday

 

[Dr. Hawk]

I don't eat much really anyway so I am not too worried. The original point I was trying to make is whats really going on, am I burning calories or not (yes) and I am quite enjoying what I am learning.