Sport Bras

Breasts are simply fatty tissue covering mammary glands. The muscle underneath the breast is buried so deep, that it does very little to actually support breast tissue. What really supports the breast is the "Cooper's ligaments", thin ligaments woven throughout the breast, which are not very strong. The tissue in your breasts is very delicate and needs to be protected during high impact exercise. Repetitive bouncing stretches the Coopers Ligiments, resulting in irreversible, premature sagging of the breasts.

To prevent the breakdown of breast tissue, it is very important to support the breasts during physical activity by using a properly fitting sports bra. To be properly supported, the breast needs to be compressed against the chest wall, as well as lifted and supported by the back and shoulders. Sport bras are designed to support the breast during vigorous physical activity as well as allow for the evaporation of sweat.

Before Buying Any Sport Bra Determine Your Correct Bra Size

Studies have found that 70% of all women do not know their correct bra size. In part that is due to the fact that breast size is not constant, but varies with pregnancy, breastfeeding, and during a women's menstrual cycle. Having a bra that fits properly can prevent back problems, muscle tension, and headaches.

A properly fitting bra is especially important for young girls. Growing breast tissue is extremely delicate. Teenage girls should be fitted by a bra expert at least twice a year, or after every noticeable growth spurt, to ensure that growing breast tissue is always properly supported.

Please Note- A poorly fitting bra can lead to long-term back pain and permanent problems with posture. Exercising without a sports bra can lead to irreversible, premature sagging of the breasts.

How To Determine Your Correct Bra Size

Step One: Determine Your Rib Cage Diameter 

Measure the diameter of your chest just below your breast.

Step Two: Determine Your Cup Size

Add 5" to the measurement you had for your ribcage diameter. If the measurement you get is an odd number add an additional 1" to your total because bras are only offered in even sizes.

For example:

Rib cage diameter = 26" (Add 5") = 31"
Because 31" is an odd number add one additional inch.
Your bra size should be a "32".


Step Three: Determine Your Largest Chest Size Circumference

Measure the diameter of your chest across the largest part of your breast.

Step Four: Determine Your Cup Size

Subtract your "bra size" from your "largest chest circumference.


To Continue the example from above:

Ribcage diameter = 26" (Add 5") = 31"

Because 31" is an odd number add 1".

Your bra size should be a "32"

If your largest chest diameter was 36"

To determine your cup size subtract 32" from 36" = 4"

Using the chart to the right, your cup size would be a "D".

Your Bra Size would be a "32D"

1/2"   AA
   1"    A
   2"    B
   3"    C
   4"    D
   5"    DD or E
   6"    F
   7"    G










A Special Note for Women With Breast Implants: If you have had breast implants remember that implants tend to run wider than a natural breast. Therefore, if measurements show that you are a C cup, you may need to go up to a D cup in some styles of bras.

Garment construction

Sports bras come in two basic styles, compression and encapsulation. Compression designs bind and press your breasts against the chest wall. Encapsulation designs separate breasts into individual cups using back and neck straps to pull the breasts up and hold them in place as you move. Small breasted women can get by with a compression style bra, whereas larger breasted women will need both a bra that compresses the breast, as well as a bra designed to lift and separate the breast. Extremely large breasted women may want to wear two bras when working out.


  In general terms most compression style bras are easy to comfortably fit. They are generally made of lycra-based fabrics which provide both, great support, and stretchable comfort. Compression style sport bras are fine for AA and A cup sizes. Depending on the fabric, B cups may also be fine in a compression style sport bra. Cup sizes C and up should wear an encapsulated style of sport bra, which is much more complicated to properly fit.


In order for the encapsulated style of sport bra to fit comfortably, the back of the bra needs to be designed to pull the breast against the chest wall, while at the same time help the shoulder straps lift and support the breast without cutting into shoulder muscles. The straps of the bra should not bear most of the weight of the breast. Instead, the back of the bra combined with the straps should fit in a way that the compression force of the bra helps support the weight of the breast.

Sport Bra FIt

Now that you know how to determine your bra size, and understand the two basic styles of sport bra (compression and encapsulation) you can begin to look for the sport bra that is right for your body type and activity level. All bras should fit comfortably snug. You need to be supported, but able to breath freely during exercise.

The secrete to finding the bra that is right for your specific body, is to try on many different bras until you find one that fits comfortably snug everywhere. Once you find that one perfect bra, jump up and down, stretch, and move to see if it is really limiting breast bounce.


The band just under the breast is designed to hold the bra in place. The band is usually made of elastic so that it can fit tight enough to do its job without being uncomfortable. The band of a correctly sized bra will fit firmly around your chest just under the breast and not ride up in the back. If the band is cutting into your ribcage as you breath, go up to a larger bra size. If the band is slipping upward as you stretch... if your breasts are falling out from the bottom of the bra... or the back of your bra is riding up, go down one bra size.

When trying on a bra for the first time, put the fastener on the loosest setting rather than the tightest setting. If you end up purchasing the bra, this will allow you to tighten the band over time, as the fabric stretches with wear and washing, keeping the same fit as the day the bra was purchased.


The cup should completely contain the breast. If you're breasts are bulging out of the tops or sides, the bra's cup size is too small. Try on the next largest cup size. If your breasts are not filling the cups, you will feel your breasts bounce as you move. If you feel breast movement, go down one cup size, or try on a different sport bra.


If you are purchasing the encapsulation style of sport bra, the center panel is the flat panel that lays between the two cups. The center panel should lay flat against your breastbone. If it does not, your cup size is too small, or the panel is not large enough to accommodate the separation between your breasts. You will need to go up a cup size in that particular bra, or try a new bra with a greater separation between the breasts.  


When purchasing a sports bra, it is important to look at the design of the straps, and how the straps attach to the back of the bra. Bra straps vary in thickness, and width. The Straps should lay flat on your shoulders. The front straps should lie in a straight line up from the nipples providing optimal vertical breast support. Straps should stay in place without digging into shoulder muscles. If your bra straps keep falling, consider a different style of bra that has straps closer together. If straps dig into you shoulders, consider a bra with wider, non-elastic shoulder straps, or a bra with a smaller band size to reduce the strap's strain on your shoulders


An under wire should encircle your breast without poking, protruding or pinching


Seams should not be placed over your nipples because they could potentially cause chaffing and irritation. Make sure that the bra, as sewn, does not have any seams that will rub or irritate you as you move.


Most sport bras will be made of a combination of fabrics. Breathable, wicking fabrics will help wick sweat away from the breast. The addition of lycra will allow the bra to be supportive without being uncomfortable. Most sport bras have great horizontal stretch compared to the vertical stretch. This allows the bra to expand as you breath, but helps eliminate vertical breast bounce.


A sports bra should not cut into the skin near your armpit, because armhole chafing will result.


All hooks and fasteners should be covered to prevent skin irritations.