Category: Health & Safety

I have said elsewhere that your body moves differently in the water, and it’s true. Even experienced athletes and Olympic swimmers have to make adjustments to accommodate water’s effect on the body.

Viscosity, Density and Resistance

Water is more dense than other mediums like air we are used to moving in. We can move through air from one place to another pretty quickly because the molecules in air are not packed very closely, which is the same thing as saying air is not very dense.

It’s harder to move through water from one place to another because water molecules are packed together more closely than air molecules. Water is denser than air; 800 times more dense to be more exact. (Salt water is even denser than other water, which makes it great for floating but more of a challenge for moving and swimming.)

Because water is denser than air, moving through it takes more effort than moving through air. The challenge you notice means you are getting resistance from the water. You are actually pushing the water out of the way every time you move, even if you are walking. Your muscles are moving against resistance, the same thing they do when you do resistance or strength training. People (and their muscles) generally aren’t used to getting this kind of resistance when they move, which is the primary reason I recommend newcomers to Aqua Zumba start out in a gentle class, even if they have strong muscles and exercise a lot. (There are other reasons your muscles don’t operate the way you expect in water, but I’m saving that for a different post.)

BUoYANCY

Another property of water that makes Aqua Zumba a little different than other types of exercise is the buoyancy factor. As I said above, water is more dense than air. Water is also a lot more dense than human bodies. If one object is more dense than the medium it is on or in (like air, water, mud, or oil), the more dense medium will push the less dense object up, which is referred to as the buoyance factor. Helium balloons float on air because the helium inside the balloon is less dense than the nitrogen/oxygen mix of air. Because they weigh less than the air, the air pushes them upward. Similarly, most human bodies are less dense than water. If you let yourself relax completely, the water will push you up to the point where you are floating on top of the water. The exception to this is people with a lot of muscles. Muscles are more dense than air, so people with very muscular bodies might not be able to float.

How much you float depends to some extent on how much of your body is immersed in the water. If you stand in water up to your waist, you will feel the water trying to push you up, but you will be able to resist it pretty easily. If you stand in water up to the bottom of your ribs, you will begin to float. If you stand in water as high as your armpits, you will have to fight to keep your feet on the bottom of the pool as the water tries to push you up. One of the great effects of buoyance is that the water starts to support your body and that takes the load off your muscles and joints. How much support?

Depth of a 200-pound body in water	Share of weight supported by muscles and joints(%)	Share of weight supported by water
Waist high	100 pounds (50%)	100 pounds (50%)
Ribcage height	70 pounds (35%)	130 pounds (65%)
Armpit height	60 pounds (30%)	140 pounds (70%)

Notice that, even if you are only submerged to your waist, the water picks up 50% of your body weight, leaving your muscles and joints with only half of the load they’re used to. As your body goes into deeper water, up to your armpits, the water supports an amazing 70% of your weight, substantially reducing the weight being supported by your muscles and joints.

For those of us with weight issues or joint issues, it feels like we’re almost flying when we get in water up to our armpits (which is the depth I recommend for you when you do Aqua Zumba). This is the key reason that physical therapists who are familiar with water exercise suggest their patients who have arthritis or bone-on-bone issues in their joints give water exercise a try. They can move their muscles and joints with less strain, which lets them get stronger without hurting. I consider buoyancy to be water’s superpower; it makes exercise much easier for everyone.

HYDROSTATIC Pressure

“Hydrostatic” comes from two Greek words meaning “water” and “standing”. Hydrostatic pressure is pressure from standing water. Because water is constantly pushing against the objects it encounters, it will push against your body from all directions. This has a few funny effects on your body.

First, your body is going to have to adjust its balance to keep you standing up — which is great practice for your brain to react to pressure.

Second, the water is producing a kind of massage against your body. This has the effect of making your blood flow more quickly than it would if you were standing in air, which lowers your heart rate, since your heart doesn’t have to work as hard to move the blood. Medical studies suggest that your heart rate is 5-10 beats per minute slower while doing exercise in the water than it would be if you were doing the same exercise on land.

Finally, the hydrostatic pressure actually helps you keep your balance. Imagine thousands of tiny little hands pushing on your body. If you begin to shake or fall, the little hands push you back into place. This makes doing exercises that are designed to improve your balance and reduce the chance of falling a lot easier because you are less likely to fall down while you are in the water.

I can’t swim. Can I still do Aqua Zumba?

Absolutely! Aqua Zumba is danced in the shallow part of the pool. To get the full benefit of buoyancy and moving your arms against resistance, you are encouraged to stand in water that is as high as your armpits, but you can stand in water that only reaches your waist if you are uncomfortable at first. Your head will never go below the water line and you usually won’t even get your hair wet (unless you splash yourself).

I can’t dance. Can I still do Aqua Zumba?

You sure can. There is an old saying among the people of Zimbabwe: “If you can walk, you can dance.” Believe it or not, if you are able to walk, you already know some of the movements we commonly do in Aqua Zumba and you will be able to pick up variations of those movements very quickly during your first class. I have only two rules for Zumba classes: 1) Keep Moving. 2) Have fun. As long as you are moving, you are doing it right. If a particular movement does confuse you, fill in with something else and see me after class to get an explanation of how to do that troublesome move.

Do I need special equipment?

No equipment needed. In fact, you are discouraged from using equipment that you might have used in other aqua exercise classes because it might make it harder for you to move through the water.

Can I join in a class that has already been meeting?

The short answer is “Yes!”

We now offer two different Aqua Zumba classes at the William G. White Family YMCA — Gentle and Exp.

The Gentle class is intended for beginners and those of us who like to dance but also like to take it easy. You are always welcome to drop in on this class.

The Gentle class meets on Fridays at 2 PM.

The second Aqua Zumba class is Exp, which stands for experienced. I assume people in this class are comfortable with moving in the water and have stronger arms and legs than typical members of the Gentle class. You can also give this class a try anytime, but you might find it useful to attend the Gentle class for a few weeks before you try the Exp class.

The Exp class meets on Wednesdays at 2 PM.

I don’t exercise now because I’m afraid of falling. Will that be a problem in Aqua Zumba?

No! In fact, water exercise is a perfect way to improve your balance, walking gait, and muscle strength to make you less likely to fall on land. Consider these factors —

• You can’t fall down in the water. I actually spent time in the pool one day trying to fall down. I couldn’t do it. After 20 minutes of throwing myself against the water, I concluded it is impossible to hit the bottom of the pool once you are actually in the water. You can fall over, but you won’t hurt yourself doing that.
• Bouyancy keeps you floating and prevents falling. I discuss the buoyancy property of water in another post on this site, but the short story is that the water will try to push you up and keep you floating, which makes falling down impossible.
• Hydrostatic pressure helps you with balance. I discuss the hydrostatic pressure property of water in another post. The short story here is that the water pushes against you and makes it much easier to maintain your balance, even if you are standing on one leg.
• Many dance moves have the effect of making your balance better. New dancers are usually not aware of this, but most of the moves you make in Aqua Zumba require you to balance on one leg (the “anchor leg”) while moving the other leg (the “active” leg). The balancing only lasts for a short time in any given move, but repeatedly balancing on an anchor leg makes that leg stronger and more fit, which makes it easier for you to avoid falling both on land and in the water and to recover quickly if you begin to fall.
• Moving in the water helps to convince your brain that you are not going to fall. “Fear of falling” is usually as much a “brain” problem as it is a physical problem. If you have fallen in the past, your brain stores a message that “moving leads to falling and falling leads to injury.” As a result, your brain launches a warning to your body to discourage you from doing anything that might cause you to fall. As you practice movement in water without falling, your brain will be less afraid that you will fall, so that fear will begin to recede. At the same time, moving in the water will build strength in your leg muscles, making it less likely you will fall. It’s a win-win kind of thing. By all means, give water exercise a try.

More questions? Email me at info @ dancingcougar.net

Zumba Fitness Corporation used to describe Zumba as “exercise in disguise”. On this, I totally agree with them.

I was an expert-level couch potato from the time I was six until the year I turned 65. That was when I was told I had Type 2 Diabetes and needed to change my eating habits and get more exercise.

I hate to exercise, but I love to dance. So, when I was told dancing counts as exercise, I was overjoyed. It took me a while to get build up the strength in my arms and legs and lungs and heart, but I now can dance 60 minutes at a time enjoying every minute.

So…I would say that Zumba can be right for you, particularly if you too hate to exercise. Somehow, dancing and moving to the music are worlds apart from squats and knee bends and reps and that stuff they talk about in exercise classes and training sessions.

Will it hurt?

The number one reason people don’t like to do physical activity is they are afraid it will hurt and/or they are worried about making physical challenges they already have — like arthritis, joint pain, or other conditions — worse.

I am a doctor but I’m not a physician. (I have a PhD in government.) Please see your primary care person (doctor or PA) or your trainer (if you have one) before you get too hooked on Zumba. They know you and your body and they will tell you if you can exercise. There’s a very strong possibility they will be delighted you want to get moving and will encourage you to give it a try.

If you don’t have a physical challenge and/or if your PCP says it’s okay, you can do Zumba. If you’re a dedicated non-mover, it might take a while for you to get up to speed — by which I mean “get your muscles and joints used to moving” — but you really can do it.

More on hurt — Aches and Pains