FROM humble beginnings -- the first modern sports bra was fashioned from two jockstraps sewn together -- the sports brassiere has emerged as a high-tech apparel powerhouse.
A triumph of engineering over gravity, these slight pieces of fabric are now researched and tweaked to the minutest detail. Some are even tested in biomechanical labs with cameras rolling, reflective tape recording every bounce of the breast, every twist of the nipple.
Just one garment can include eight types of fabrics, with varying amounts of support, sweat-wicking properties and ventilation levels. As a category, they're made with ever-more-smooth microfibers to reduce friction. Even the straps are specially engineered, some with gel inside for added cushioning.
These advances have been fueled by the growing expectations -- and changing needs -- of women and by the indefatigable efforts of researchers who have made bounce analysis and nipple-tracking a fine art.
One of those scientists, LaJean Lawson, has been conducting sports bra research at Oregon State University's biomechanics lab for nearly 20 years. Today she is an adjunct professor in exercise and sports science and works with Champion Athleticwear to test and improve sports bra designs.
Tracking the smallest detail
To test a bra, Lawson relies on a shifting group of volunteers with varying breast sizes. The women jog on a treadmill at a 6-mph pace, while six cameras set up around them feed data into a computer. Lawson is able to track the motion of the breast in the bra to the smallest detail.
At the end of each trial, Lawson will have simulated figures of the subject's entire body in motion and of the breasts, moving up and down in space. She can track in slow motion every twist and turn of the breasts, which tend to move in a figure-eight pattern that reflects the arm swing and shoulder rotation during running.
"We can tell you how fast the nipple is going as it changes direction," she says. "We can calculate velocity and acceleration." In fact, she says, some of the data are kind of scary.
"Think of when you play crack the whip," she says. "The skin and much of the underlying tissue in the breast is somewhat elastic, so when you have a breast traveling downward at a pretty good rate of speed, and then you change direction as your body hits the ground and begins to rise up again, you can get some pretty drastic acceleration as the breast speeds up to try to catch up with the rest of the body. The point of the sports bra is just to slow all that down."
The average 36C breast is estimated to weigh about 10 ounces. Researchers calculate that a breast of this size, with minimal support, running at about 5.6 mph, will bounce as much as 4.7 inches up and down, relative to trunk movement. A good sports bra can decrease this by about one half or more.
Today, Lawson says, breasts are moving somewhat differently in the bras that she's used as controls over the years. This is due, she suspects, to a higher ratio of fat-to-glandular tissue in the breast. As women have become larger, breasts have followed suit. In the last 10 years, breasts have increased from an average bra size of 34B to 36C or 38C.
The new bras, of course, are following the demand, with better engineering for the bigger breast.
To fully understand the breast, one must start with the fine strands of connective tissue, called Cooper's ligaments, that separate its lobules. Researchers believe that these ligaments, along with collagen and skin tissue, give the breast its gravity-defying structure. Over time, however, as these tissues become less elastic, breasts lose their perky resilience. A sports bra, in theory, should slow the advent of sagging.
Not everyone is convinced, however. Dr. Jaco Festekjian, an assistant clinical professor of plastic and reconstructive surgery at UCLA, has performed more than 1,000 surgeries on breasts, including reconstructions, augmentations and reductions. Genetics and other factors such as pregnancies, he says, are most likely the biggest determinants of sag.
"The bra can't control the inherent elasticity of the ligaments," he says. "The ligaments that hold the breast up loosen over time, with or without a bra, and once they succumb to gravity, they don't want to bounce back."
Whether bounce causes sag may be debatable, but comfort isn't.
Artwork and relics dating back to Greek and Roman antiquity suggest that active women through the ages have grappled with the problem of bouncing breasts, says Kevin Jones, a costume historian at the Fashion Institute of Design and Merchandising Museum in Los Angeles.
"We know from mosaics in AD 340, for example, that women in Sicily exercised in gymnasiums, with barbells, in what looks like sports bras," he says. "Women at that time did participate in athletics, which ended with the Medieval era, when women's roles in society became more regulated and restricted."