Does more muscle mean less buoyancy?

[nublikescake]

Let's say a guy with an average body works out and develops a good amount of muscle mass and lowers his body fat percentage compared with his earlier, average self (higher fat percentage). BUT...the surface area of his body has also increased all over.

Is he less buoyant now because of the increased muscle mass or does the increased surface area sort of counterbalance it? Or is the surface area negligible?

Anyone personally experience the above situation?

 

[TallBill]

Yup, I sink

 

[Crono]

Doesn't muscle have near equivalent amount of water (or perhaps higher than) as fat?

 

[spidey07]

Yep, less buoyant. I sink in fresh water but float in seawater. Muscle = more dense, fat = less dense.

 

[invidia]

I was never taught much about fluid mechanics, despite having a physics degree. I would guess yes, since bouyancy is involved with mass and not much or anything to do with surface area.

 

[Crono]

Originally posted by: spidey07
Yep, less buoyant. I sink in fresh water but float in seawater. Muscle = more dense, fat = less dense.

You dared to timewarp me?

 

[Crono]

OK, Wikipedia chimes in: "Increased body fat will result in greater buoyancy, while greater muscle mass will result in a tendency to sink."
http://en.wikipedia.org/wiki/Body_composition

 

[Pheran]

Muscle is denser than fat, so yes, if you lower your body fat percentage, you become less buoyant. Surface area has nothing to do with it. According to google, muscle density is approximately 1.06 g/ml whereas fat density is 0.9 g/ml.

 

[nublikescake]

Damn. But but but....I've seen Ahhhnold swim in movies!

 

[spidey07]

Originally posted by: nublikescake
Damn. But but but....I've seen Ahhhnold swim in movies!

That's what your lungs are for - to prevent you from sinking like a rock. Anybody with a full breath of air will float or at the very least be able to tread water. It's when they let air out that they can start to sink.