ankle weight question

[Walter]

You have yet to prove that statment and you just keep saying the same wrong BS.

You want proof that it is more work to move your legs while weighted than when they are not weighted. Get a physics text and look up the word, work.

 

[SeaHorseWoman]

For those who asked, I dive in the very salty RedSea in a 5mil ws with a 3mil vest and hood in the winter.

Walter, thanks for the lowdown on that your 4hour dive. Sounds awesome. Also for your take on my challenged legs.

TSandM, your supportive posts help me feel good about myself, as always.

Everyone, you gave me a pretty good idea of what to work on before I go buy ankle weights. Since I'm not really thrashing about and can hover pretty well, I'll try to keep my body in a good position through practice-----dive, dive, dive......
Thanks

 

[Mr.X]

Apples and Oranges. momentum yes gravity no ( except when useing certain kicks)
I didn't know your 'proper technique' was to kick at 60 times a minute.

To some extent the ankle weights can be beneficial when starting out and working out trim elements related to drysuits. I dive a variety of conditions from tropical to ice and used them with some early version, full footed drysuits. Anyone remember the Oneill Supersuit, or Bayley Suit? If you dive a Unisuit...my comments are mute. In the end, having mass at the ankles is less preferred for a variety of reasons. I'll offer some other factors:

* losing an ankle weight UW can contribute to a very real propulsion/trim issues
* darn things always get lost or taken - even labeled!
* they leak lead dust on the boat deck and inside your equipment box
* they don't make swimming easier in the long run
* teen, male dive students think they are good, soft bludgeons

X and out

 

[matt_unique]

This has been debated once or twice:

http://www.scubaboard.com/showthread.php?t=133576

 

[scubabear]

Some do, but it's not necessary. You are, however, correct that ankle weights are merely more of the same with the added exertion every time you move your legs. Ankle weights are not the spawn of Satan, merely an attempt to compensate for poor technique with equipment, similar to the use of Force Fins to compensate for bicycling. I prefer to work on technique.

Jeez, Ankle wts.,Force Fins, and I suppose purge masks, OH MY ! I personally think the use of any product that enhances a diver's comfort zone is not a problem. I would much rather see someone enjoying themselves than worrying whether their technique was a 8.9 or a 10. Of course, we could always go back to the days of strapping on lead, throwing the doubles over our heads, and kicking our asses off.
But, since I'm not 17 anymore, I'll just plod along in my F.F. and let others worry about "technique".

 

[SeaHorseWoman]

.
But, since I'm not 17 anymore, I'll just plod along in my F.F. and let others worry about "technique".

Younger than me! But the cute young guys at the dive center say I don't dive a day over 48.

 

[Luis H]

I don´t understand how anyone can honestly believe that more weight doesen´t equal more exertion. It is so basic that I don´t see a point in even talking about the rest of it if you don´t even have that understanding.

That is only a true statement if the only energy involved was kinetic energy. As in the energy related to the velocity of a mass in motion (E =1/2 m v^2).

For this discussion I am not going to address the energy related to the hydrodynamic forces caused by drag or the hydrodynamic lift caused by the fins, since that is not affected by the use of ankle weights. Most of the energy required to move your legs through the water is related to the hydrodynamic forces.

Moving the mass of your legs up and down involves to types of energy: kinetic and potential energy.

The kinetic energy is a function of the velocity square. The velocity of our legs is kind of slow so the kinetic energy level is low. The percentage change in energy due to ankle weights would be very small, especially since the percentage change of the weight is low.

Potential energy is the energy related to elevation change of a weight (E = W h = mg h). This is the energy a bicyclist has at the top of a hill that allows him to coast down or the energy required to lift a weight a certain distance above its resting place. This is also the energy required to push a buoyant object down in the water a certain distance.

The potential energy related to moving your legs up and down in the water will only be zero if your legs are independently neutrally buoyant. The over all buoyancy and trim of the diver falls on a related, but separate subject.

If your legs are heavy or buoyant the magnitude of the potential energy required to move them up and down can easily exceed the difference in kinetic energy caused by the use of ankle weights.

In any case when we are in a water media, the biggest energy related to propulsion has to do with the hydrodynamic forces (as in hydrodynamic drag).

 

[scubabear]

Sounds like my wife, she gets younger with every dive. Her fountain of youth! Welcome to a world you'll never get tired of. We're going to Hawaii this year, hope to dive Red Sea someday soon.

 

[Mad Scientist]

Ok to answer the original question YES increasing muscle mass in your legs will make your lower body negatively buoyant. I speak from first hand knowledge. I am a former college football player, I could squat well over 800 lbs and my legs were huge (over 44 inches around 10 inches bigger than my waist). Floating legs have never been a problem for me, actually quite the opposite. When I attempted to float on my back (lifeguard training) my legs would just pull me straight to the bottom. However to quantify the statement you will need to add a lot of mass to get this to happen, casual weight lifting may not be enough to get the type of muscle mass that you will need.

 

[Mad Scientist]

You want proof that it is more work to move your legs while weighted than when they are not weighted. Get a physics text and look up the word, work.

The Physics def of work needs the angle the force is being applied since we are talking about kicking straight up and down, the cosine of the angle is zero so no work is being performed....

Sorry had to let the geek in me out....