Under Armour says its new CoreShort, which has X-shaped panels in front and back, helps stabilize the body while it's moving. "The more you move, the more it works," says David Ayers, director of men's apparel for the company. As muscle tension increases, he adds, the compression in the shorts helps to make movements more efficient, "so there's no wasted motion."

The idea came from a Canadian sports physiotherapist, Ayers says, and pays more attention to anatomy, building in sections that provide support and compression for body parts that drive motion.

Staying warm

Down jackets are a must for hikers and skiers in cold climates. But those Michelin-man puffy coats may soon be a thing of the past now that companies are experimenting with Zero-Loft, a super-thin insulation created via nanotechnology and derived from silicate. The material was originally used to insulate oil and gas pipelines.

Element 21 Sports, which produces Zero-Loft, claims that the material's nanoparticles are 3,000 times less dense than glass but chemically the same and that they don't flatten out when squeezed, like down. When put into clothing, the result may have been too effective — a prototype jacket from Champion, called the Supersuit, resembled a slim windbreaker and reportedly kept a climber too warm on a trek up Mt. Everest. The four-layer construction consisted of a moisture-wicking inner lining, radiant foil to keep in heat and a wind-proof outer shell in addition to the insulating layer.

Ultimately, Champion decided not to produce the jackets. "The general consensus was that we made a large advancement in real-world conditions, but we think it still remains to be seen if there's a commercial market for it," says Matthew Hall, a spokesman for Hanesbrands Inc., the parent company.

A spokesman for Toronto-based Element 21 Sports said the company is in talks with clothing manufacturers who want to use the insulation in items such as hats, shoes and gloves. CamelBak already has it in its Podium water bottle.

Staying cool

Cooling an athlete is more challenging than keeping one warm, says Fink of MIT: "It's easier to generate heat than it is to remove it." At the moment, cooling is typically achieved via lightweight clothing that efficiently wicks away moisture so that sweat doesn't build up in the fabric. An example is a shirt developed by Polarmax used by special-ops personnel that's made from a man-made open-weave textile that feels like silk.

But clothing like that may be obsolete soon, Fink says. "Maybe evaporative cooling is the way to go. Maybe we build water into the fibers and those evaporate, cooling your shirt off. Maybe it doesn't have to be soaking wet, but it would be embedded in particular areas."

Fink believes scientists are well on the way to creating such high-tech fibers, though whether such items would ever be available for the mass market — as opposed, say, to special forces operating in hot climes — is anyone's guess, he says.

Last month Fink and his colleagues released a paper in the journal Nature Materials about the development of fibers that can detect and produce sound. Soon, perhaps, runners won't have to haul their iPods around anymore: They can listen to their shirts instead.