Filed under: Altitude
Increasing the strength of your respiratory muscles (the ones that help you breathe: your diaphragm and the muscles between your ribs) will improve aerobic fitness, especially for long-duration tasks. Respiratory muscle training (RMT) can be achieved through whole-body aerobic exercise, upper-body strength conditioning, and some commercial RMT devices. However, using your military Pro Mask or other commercial mask device as a method of RMT is not going to prepare you for higher elevations. Studies have also found that RMT only slightly improves performance in those who are already aerobically fit, (i.e., military personnel); it has somewhat more benefit for those less fit or with chronic conditions. Your Pro Mask was made to protect your lungs, eyes, and face from chemical and biological agents, radioactive particles, and battlefield contaminants. It does not create enough airflow resistance to help improve aerobic capacity, and it wasn’t designed to be exercise equipment. In addition, there is no scientific evidence to show that using commercial masks at normal altitudes will improve your performance at high altitudes. You can read more from USARIEM about using Pro Masks and commercial products for exercise training, as well an overview of current information and recommendations.
Performing physical activity at moderate (4,000-7,870 ft or 1,200 to 4,000 m) and high (7,870-13,125 ft or 2,400 to 4,000 m) altitude can be challenging. At high altitude, oxygen pressure is lower which results in less oxygen in the blood and muscle tissues. As altitude increases, there is a decrease in air temperature (about 20 F for every 500 ft or 152.4 m), less moisture so the air is drier, and increased solar radiation. Use sunscreen, drink plenty of water, and watch out for the signs of acute mountain sickness: headache, nausea, shortness of breath, impaired cognition and balance.
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.
If you’ve ever switched times zones, even as little as one hour, you may be aware that it can disturb your sleep and even disorient you in the following days. Without taking any medicinal countermeasures, you can typically adapt to your new time zone with about one hour of extra sleep per day after arrival (depending on with direction you’re traveling). However, some operations require that you be able to perform within 24 hours of arrival. To better prepare and adjust to your new time zone, use these strategies:
- One week before you travel, adjust your sleep schedule about one hour per night towards the time zone you are flying in—i.e., if flying eastward, go to bed and get up earlier; if flying westward, sleep later.
- Before you take off and while on the aircraft, eat light snacks, avoid alcohol, and stay hydrated (with water).
- On the aircraft, make sure that you are comfortable and able to nap before you arrive at your destination.
- Setting your watch to your new time zone as soon as you board your flight will help you transition.
- Take a short nap when you arrive at your new location, if you’re able to do so.
For more information, read the sections on jet lag in this article on sleep rhythms.