Filed under: Gear
Walk into any fitness center on base or take note of a group of soldiers training, and you’ll probably notice at least a few people in form-fitting synthetic t-shirts. The sports apparel industry has exploded in popularity over the past decade, with numerous manufacturers now competing to develop, market, and sell the newest pieces of clothing (shirts, shorts, underwear, socks), all geared to keep athletes cool while competing or training in hot environments. Is there any science behind these claims? Does tight-fitting clothing made of “high-tech” materials actually help with heat regulation and enhance athletic performance?
You heat up when you exercise, and sweating is the primary method your body uses to stay cool. Sweat evaporating off your skin is the most important method your body has to cool itself during exercise. High-tech materials are supposed to enhance “wicking”—the delivery of sweat away from the skin surface toward the clothing, which allows for evaporation—and limit the absorption of sweat by the clothing itself. Cotton, by contrast, absorbs moisture, so it’s not considered a good choice for exercise.
To date, there’s no evidence that this high-tech clothing improves thermoregulation when worn during exercise in hot environments. Specifically, researchers found no differences in heart rate or body and skin temperatures when subjects performed repeated 20–30 minute bouts of running outfitted in shorts, sneakers, and either a form-fitting compression or traditional cotton t-shirt. Research has also found that wicking sportswear had no effect on cooling when worn under a bulletproof vest or on a cycling sprint when worn under full ice hockey protective equipment. As of now, the best advice for staying cool during exercise in the heat is to wear lightweight clothing, stay properly hydrated, and listen to your body for signs of potential heat illness. For more information on performing in hot environments, please visit the “Heat” section of HPRC’s Environment domain.
Pentagon scientists are hoping to build special gear designed to turn divers into veritable Aquamen (and Aquawomen). Although it’s still in the research phase, the new system would protect divers from the adverse effects of diving too deep or surfacing too fast. Sensors would read and adjust to a diver’s physical signs as well as help control levels of nitric oxide to prevent the decompression sickness known as “the bends.” When a diver ascends too quickly, bubbles form inside the body, which can block the blood vessels in the spinal cord and disrupt the nervous system. It can be very painful and can lead to joint pain, paralysis, and even sudden death if a diver is not careful.
The new diving gear will be a portable and versatile system that can potentially serve for use in other special operations as well as for civilian divers. This system will have to be designed for the most extreme combat dive profiles, which sometimes require a 35,000-meter free-fall from an aircraft, diving 200 feet below the surface for at least two hours, surfacing, and immediately diving again, followed by continued protection after being picked up in an unpressurized aircraft. This is one of DARPA’s most recent Small Business Innovation research proposals for 2013.
Before the end of October of 2012, the Army will issue to all soldiers fire-resistant ACUs that have been factory treated with an EPA-approved insect repellent called permethrin. This method may be a cleaner and safer way of repelling insects compared to DEET, another long-lasting insect repellent. The Army has been using permethrin for nearly 20 years in the form of liquid or spray, and by treating ACUs, soldiers will experience better, longer-lasting protection against ticks, fleas, mosquitos, and other insects that carry diseases such as malaria, West Nile virus, and Lyme. Other advantages include not having to worry about remembering to apply insect repellant and whether you’re applying it correctly. Uniforms treated with permethrin have been used by the Marine Corps since 2007 and have been used in some Iraq and Afghanistan operations but until now have not been available to all soldiers. The new ACUs will be good for about 50 launderings, but it is important to note that the uniforms should be washed separately from other clothing. There will be a permethrin-free ACU available for those with medical conditions, including pregnant women, who should not wear the treated uniforms. For more information check out these FAQs or contact the Armed Forces Pest Management Board.
Body armor, in addition to necessary equipment and supplies, well exceeds the recommended carrying maximum of 50 pounds. The DoD was asked by Congress to conduct a research project to explore the possibility of lightening body armor without sacrificing protection. Currently, the research shows it does not seem possible to make body armor out of a lighter material while still adequately protecting the individual. However, leaders are taking a more preventative approach to reducing injuries on the battlefield. These include changes in pre-deployment training, as well as an increased number of deployed physical and occupational therapists and improvements in forward-deployed care centers.
Why has the F-22 Raptor been depriving its pilots of oxygen for the last 12 years? Air Force officials recently told a House subcommittee hearing (a complete video of the two-hour hearing is also available) that they don’t know what’s behind the dizziness, confusion, blackouts, memory loss, fatigue, and eventually chronic cough (“Raptor cough”) that pilots experience while flying the stealth jets. After more than a dozen incidents between 2000 and 2011—and one fatal crash—where pilots were being choked by the plane, the Air Force’s entire F-22 fleet was grounded in May 2011.
Investigations ruled out low blood sugar and dehydration as possible causes of the symptoms and eventually concluded that the problem was an overinflated pressure vest that restricted breathing.
In response, a team of NASA engineers and Navy divers developed a new-and-improved pressure suit and back-up oxygen systems and removed a faulty charcoal air filter. These measures seem to have alleviated the problems—a dozen F-22s recently were deployed to Japan without incident. Now restrictions are being lifted, although the jets and their pilots are being closely monitored. Pilots currently must operate under altitude ceilings so that they don’t need to use the flight vests, and they must also stay close to emergency landing sites. Experts and scientists continue to investigate the primary cause of these incidents as well as improve safety and back-up systems.