Ankle weights

[matt_unique]

Sure you would. If you were wearing 5 pounds on your ankles then your feet are more negatively buoyant and you use more energy moving your legs to fin, because you have to compensate for the extra weight on your ankles. Doing this causes you to breath more, which causes you to suck down a tank quicker.

This is a common misnomer. It will not make one bit of measureable difference.

--Matt

 

[amascuba]

I have two drysuits. One is a CF200 - no ankle weights. One is a USIA - ankle weights.

Here is what I've found. The USIA boots too big for me and even with fin keepers and extra socks, it is nice to have a pound on each foot to prevent floaty toes. I can and do dive the suit without the weights on the rare times I have to use it.

The CF200 on the other hand had rockboots. I never get floaty feet.

I use a frog or modified frog for nearly 100% of my dives.

I personally don't like using the weights. At the end of a dive where I have used them my legs are much more fatigued than the same dive without. For me it's not a difference of technique between the suits. One suit traps air in the feet the other doesn't. My next suit will either have rockboots or very conforming boots on it.

I have found that using a size or two smaller boot then you need helps with the air flowing to your feet. On my mobby's I have a 25cm boot (which is a 6 - 7 shoe size) and I wear a size 10/10.5 shoe. The boot fits perfectly with normal socks, but for colder water I would want a bigger boot so that I could put more layering on my feet.

 

[amascuba]

This is a common misnomer. It will not make one bit of measureable difference.

--Matt

hhhmmm .. so you're telling me all those studies about how working working muscles need more oxygen is a sham?

 

[OE2X]

I have found that using a size or two smaller boot then you need helps with the air flowing to your feet. On my mobby's I have a 25cm boot (which is a 6 - 7 shoe size) and I wear a size 10/10.5 shoe. The boot fits perfectly with normal socks, but for colder water I would want a bigger boot so that I could put more layering on my feet.

Yes agreed and you make a very good point.

My CF200 is my primary suit and the USIA is the backup that rarely gets used.

I for one do notice a difference in fatigue with ankle weights. Not sure that it effects my SAC too much as I'm generally down around .34 and a slight uptick won't be noticed in my gas planning.

 

[matt_unique]

hhhmmm .. so you're telling me all those studies about how working working muscles need more oxygen is a sham?

No, the science is dead on but not relevant to this scenario. It's again the difference between the science in a test tube and the real world of diving. There is absolutely no measureable difference in air consumed between dive #1 with ankle weights and dive #2 without ankle weights.

--Matt

 

[MarkH]

For many people, diving is a very "socially-oriented" activity. Many of these people are desperate to "fit in" and be respected within the diving community. I think that graduating elementary school gives you the right to wear no-name brand runners and not care what anyone thinks. I've heard it might be more important to be comfortable underwater than to look cool.

 

[amascuba]

No, the science is dead on but not relevant to this scenario. It's again the difference between the science in a test tube and the real world of diving. There is absolutely no measureable difference in air consumed between dive #1 with ankle weights and dive #2 without ankle weights.

--Matt

How can the science be dead on, but not relevant to this scenario? Think about it. You add more weight to your ankles then you are used to having. This means that when you move your legs you have to exert more energy to move your legs. The more energy you exert the more oxygen your muscles need. The more oxygen your muscles need the more you breath. The more you breath the faster you suck down a tank of air.

So again, how can the science be dead on, but not relevant to this scenario?

Look at what OE2X said "I personally don't like using the weights. At the end of a dive where I have used them my legs are much more fatigued than the same dive without."

His legs would be more fatigued because he worked his legs harder. That would affect the SAC rate. It will affect everybody differently depending on how good of shape you are in, how good of a SAC rate you have to begin with, how much weight you wear on your ankles, the environmental conditions, etc, but it does affect the SAC rate. You can't say "It will not make one bit of measureable difference." in on post and turn around the next and say the science is dead on in the next. That's like saying a wheel is round, but it doesn't roll.

 

[matt_unique]

How can the science be dead on, but not relevant to this scenario? Think about it. You add more weight to your ankles then you are used to having. This means that when you move your legs you have to exert more energy to move your legs. The more energy you exert the more oxygen your muscles need. The more oxygen your muscles need the more you breath. The more you breath the faster you suck down a tank of air.

So again, how can the science be dead on, but not relevant to this scenario?

Look at what OE2X said "I personally don't like using the weights. At the end of a dive where I have used them my legs are much more fatigued than the same dive without."

His legs would be more fatigued because he worked his legs harder. That would affect the SAC rate. It will affect everybody differently depending on how good of shape you are in, how good of a SAC rate you have to begin with, how much weight you wear on your ankles, the environmental conditions, etc, but it does affect the SAC rate. You can't say "It will not make one bit of measureable difference." in on post and turn around the next and say the science is dead on in the next. That's like saying a wheel is round, but it doesn't roll.

Test tube vs. real world.....There are many other examples of this nonsense. When I wear a reel, it could be proven through formula's that I have increased drag, thus greater exertion, SAC, etc. In the real world, it does not make one bit of measureable difference.

You can choose to believe what you wish.

--Matt

 

[OE2X]

I think we need to get away from putting down people that wear ankle weights as divers that cannot dive or that have lousy technique. Sure some do, but I've seen plenty of divers who don't wear ankle weights whose skills are sub par.

Now as to the arguement about weights on the ankles and it increasing fatigue and thus increasing SAC - while I don't profess to be a rocket scientist I do have to agree with amascuba here. For someone like myself, depending on the dive if I use a pair of one pound ankle weights, it might increase my SAC by as much as 10%. In an earlier post I mentioned that it wasn't a big deal since my SAC is so low, that this increase is built into my gas plan anyway. None the less if I'm swinging an extra pound at the end of the fulcrum, it will increase fatigue and thus increase my gas use.

Think of it like this: Put on a pair of heavy hiking boots. Now go out and run a mile on a treadmill where you are breathing through a gas monitor. Now come back and put on a pair of sneakers that each weigh one pound less. Do the same controlled run when you are similarly rested. Matt I guarantee that you will be less fatigued and consume less gas.

Why do you think that track stars run in shoes that weigh just a few ounces or all the Tour de France bikes weigh as little as possible? Extra mass increases energy usage and for people that means a greater consumption of O2. A small car will burn less fuel because of lower mass and an aerodynamicly smaller foot print than a large truck.

Is this a big deal? No. If you are a hoover, you still suck gas even if you aren't wearing AW's. Do you suck as a diver because you wear AW's? Not necessarily. They can be used as a tool to overcome poor technique for some. Then too, negative weight fins could be seen by those who use fins made out of old floaty surfboard materials as a crutch.

People - I think what Matt takes offense to is that he feels that people look down on those who use ankle weights. Time to relax and let people dive the way they want.

Ankle weights don't kill divers - computers do. Just kidding everyone.

 

[String]

How can the science be dead on, but not relevant to this scenario? Think about it. You add more weight to your ankles then you are used to having. This means that when you move your legs you have to exert more energy to move your legs. The more energy you exert the more oxygen your muscles need. The more oxygen your muscles need the more you breath. The more you breath the faster you suck down a tank of air.

Quite simply because the extra increase in effort to move say 2lb when combined with everything else can be so small its insignificant, unmeasurable and have absolutely no real world effect. If the effort reduces your air by 2 seconds on a 45 minute dive you arent going to notice.

Also it can go the other way, in keeping a diver in horizontal trim so hes not constantly fighting rising feet they can actually REDUCE air consumption as less effort is required to stay in trim.

Ive yet to see one single properly researched work that shows a noticable and significant increase in air consumption due to ankle weights.