Filed under: Environment
Altitude affects what your body needs and how it responds, especially when it comes to exercise. Acute mountain sickness (AMS)—caused by dry air, a decrease in oxygen, and low barometric pressure—can severely impact your health and performance. The good news is there are things you can do to help reduce your risk of altitude sickness.
Performing physical activity—whether you’re at the gym or on a mission—at moderate (4,000–7,900 ft or 1,200–2,400 m) and high (7,900–13,000 ft or 2,400–4,000 m) altitudes can be challenging. At high altitude, oxygen pressure is significantly lower, which results in less oxygen in the blood and muscle tissues. And as altitude increases, there’s also a decrease in air temperature (about 2°F for every 500 ft or 150 m), less moisture (resulting in drier air), and increased solar radiation. AMS can affect anyone who is unacclimatized and ascends too rapidly to high altitudes. Symptoms can include headache, nausea, fatigue, dizziness, vomiting, sleep problems, shortness of breath, dehydration, and impaired cognition and balance.
The risk and severity of altitude sickness are greater above 4,000 meters, and treatment might require evacuation to lower altitude or immediate medical attention. To reduce your risk of AMS, wear sunscreen, drink water, and try to limit your physical activity at altitude for the first 24 hours. Acclimate to moderate elevations (2,000–3,000 m), if possible.
With current and future military operations in mountainous regions, the issue of AMS is a serious concern. However, leaders can help manage and perhaps prevent AMS among Warfighters by being aware of the elevation, types of activities, and lengths of stay at altitudes. Visit HPRC’s Altitude section to learn more about performance at altitude.
Take note: Your sunscreen—important for protecting your skin from the sun’s harmful ultraviolet rays—has an expiration date! Just as you wouldn’t expect to feel well after eating expired food, don’t rely on expired sunscreen to protect you from the sun.
Sunscreen can be effective for up to 3 years. After that, its active ingredients start to deteriorate, leaving you vulnerable to sunburn and sun damage. Ideally, you should use sunscreen often enough that your bottle doesn’t last through the summer. If that’s not the case, check the bottle you’re currently using. If it’s old, throw it out.
If you buy sunscreen with the expiration printed only on the box or wrapper, use a permanent marker to write the date somewhere on the bottle. And store it in a cool, dry place. Practice safe sun this summer to keep your family healthy and happy!
The Altitude Readiness Management System (ARMS) app’s designed to predict how likely Soldiers are to experience acute mountain sickness and decreased physical performance at various altitudes. Using this new Android app (developed by the U.S Army Research Institute of Environmental Medicine), leaders can plan mountain missions around those likely to be impacted by sickness.
The ARMS app also provides an acclimatization module for planning strategic ascents and rests to minimize sickness. Altitude sickness can cause serious symptoms including nausea, fatigue, headaches, and weakness, affecting health and the mission itself too. While the app can’t prevent illness, it can help minimize the impact of mountain sickness, set appropriate expectations, and improve readiness and performance. The app has been fielded to the U.S. Army Forces Command (FORSCOM) and the U.S. Special Operations Command (SOCOM) only, but it might be available to the public soon.
Sneezing, runny nose, watery and/or itchy eyes, and fatigue? Both colds and seasonal allergies make you feel miserable, but you can take steps to avoid or at least take the edge off them. To do so, though, you need to understand which is which. The causes are distinctly different: Colds are caused by viruses, which means they’re contagious. Allergies come from sensitivity to “allergens” such as seasonal pollen, and they’re not contagious.
You can avoid colds through hygiene such as washing your hands thoroughly, especially after touching public surfaces such as handrails. You can avoid “sharing” a cold by covering your mouth or nose when you cough or sneeze or simply by staying home when you’re sick.
To avert seasonal allergies, on the other hand, you must avoid the allergens (mostly airborne) that cause your symptoms. Common allergens in spring include grass and tree pollen. It can be a challenge to exercise and enjoy the outdoors if you have allergies, but it’s not impossible. Here are some tips to help you manage your allergies:
- Know and avoid your allergy triggers. If you aren’t sure what you’re allergic to, have tests done by a healthcare specialist to help you narrow it down. Your doctor also might suggest an antihistamine, inhaler, or medication to help prevent flare-ups.
- Check the air quality in your area every day. If the pollen count (app available!) is high, avoid spending too much time outside, mowing the grass, or exercising outdoors.
- If you must be outside during high-pollen/pollutant times, wear a filter mask to keep particles out of your nose and mouth. If you have to go somewhere, keep your car windows shut.
- Shower when you come back indoors to wash pollen off your skin, hair, and eyelashes.
- Rinse out your nose with a saline spray or solution to help wash away allergens after you’ve been outside.
Winter isn’t over yet, so here’s a reminder: You can get dehydrated in cold weather. And it isn’t always easy to hydrate, especially when you’re on a mission. If you’re active outside for less than 2 hours, it isn’t likely to be a problem. But if you’re out in the cold for hours or even days for a field deployment, the combination of heavy clothing and high-intensity exercise can lead to sweating, which contributes to dehydration.
You might not even feel as thirsty in cold weather as in the heat, because your cold-weather body chemistry could affect your brain’s ability to tell you when you need liquid. Cold weather also tends to move body fluids from your extremities to your core, increasing your urine output and adding to dehydration.
So when you’re in a cold climate, don’t rely on thirst to tell you when you need to drink. Drink often and before you’re thirsty. One way to determine your hydration status is to check the color and volume of your urine. (Snow makes a good test spot.) Dark, scanty urine indicates dehydration. Ideally, urine should be light yellow.
Water and sports drinks are the best fluids to maintain hydration, even in cold weather conditions. Carbonated and caffeinated beverages (including energy drinks) have a dehydrating effect because they increase urine flow. Also avoid consuming alcohol in cold weather. It might make you feel warm initially, but it can reduce your body’s ability to retain heat.
Enjoy exercising in the cold weather, but be sure to keep your water bottle in tow.
Don’t let cold weather freeze your exercise routine. Use these tips to stay motivated, safe, and warm.
- Dress in layers. Choose synthetic materials such as polyester or polypropylene that stay close to the skin. Avoid cotton since it soaks up sweat! You can always remove layers as you get warmer.
- Protect your extremities—especially your fingers, toes, and ears. Circulation to these areas decreases in cold weather.
- Check the forecast. Wind chill, snow, and rain can make your body more vulnerable to the outside temperatures. Plan an indoor workout when the wind chill is extreme or the temperature drops below 0°F.
- Apply sunblock. You can still get sunburned in the winter so don’t forget the sunscreen!
- Stay hydrated. When exercising in cold climates, don’t rely on thirst to indicate hydration since you usually don’t feel as thirsty in cold temperatures. You need to stay just as hydrated in cold weather as you do when it’s hot outside.
- Ask your doctor. Certain symptoms might worsen in cold weather if you have asthma, heart issues, or Raynaud’s disease (when specific body parts feel numb due to to cold temperatures or stress). Talk to a healthcare professional about your concerns before heading outside for your cold-weather workout.
Using your military Pro Mask or other commercial mask device as a method of respiratory muscle training (RMT) isn’t going to prepare you for higher elevations. Increasing the strength of your respiratory muscles which help you breathe—your diaphragm and the muscles between your ribs—will improve aerobic fitness, especially for long-duration tasks.
RMT can be achieved through whole-body aerobic exercise, upper-body strength conditioning, and some commercial RMT devices. Studies show that RMT slightly improves performance in those who are already aerobically fit (e.g., military personnel). It offers 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 doesn’t create enough airflow resistance to help improve aerobic capacity. In addition, it wasn’t designed as exercise equipment. There is no scientific evidence that suggests using commercial masks at normal altitudes will improve your performance at high altitudes. Read more about the U.S. Army Research Institute of Environmental Medicine’s (USARIEM) review of Pro Masks and commercial products for exercise training. Check out HPRC’s take on using high-altitude masks and improving work performance at higher elevations.
Noise-related hearing loss is a tactical risk for individual warriors and unit effectiveness. Being able to hear well is crucial for effective communication and—perhaps more important—for survival. While the military has done extensive research and established standards regarding noise and noise exposure, there are a few things you can do to help minimize your risk of this occupational hazard.
- Wear hearing protectors when firing weapons or traveling in noisy vehicles or aircraft.
- Make sure that earplugs such combat arms earplugs (CAE) fit properly to protect your hearing but still communicate effectively.
- Replace lost or damaged hearing protectors as soon as possible.
- Limit exposure to “annoying noise” during normal daily activities. Trying to ignore noise can increase your heart rate and blood pressure and cause sleep problems and other negative health effects.
- Report any signs of hearing loss as soon as possible.
Hearing loss, including tinnitus, has become an "invisible" injury and an accepted outcome of military service. Blast injuries from improvised explosive devices (IEDs), RPGs, and mortar rounds are the largest cause of hearing loss for forces in Iraq. Compensation payments for hearing loss as the primary disability increased 319% between 2001 and 2006. While there is currently no cure for tinnitus, there are treatments available.
The DoD Hearing Center of Excellence is committed to preventing, treating, and rehabilitating hearing loss and auditory injury for service members and veterans. HCE offers evidence-based clinical care in collaboration with other organizations and Centers of Excellence to improve quality of life for hearing-impaired service members and raise awareness about noise pollution and occupational safety.
Noise pollution may be an inevitable part of serving in the military, but it doesn’t have to leave you with a permanent reminder. Do what you can to help hold on to your hearing.
Sitting in front of a computer for hours can make your eyes tired, and your visual performance can suffer. To help with potential negative effects, create an environment that has equal brightness everywhere around your computer screen. Try these tips to help:
- Reduce intense fluorescent lights.
- Turn on some lights if you usually look at computer screens in the dark.
- Dim excess light coming through windows with blinds, tinting, or window covers.
- Avoid glare on your computer screen.
- Take microbreaks to look at distant objects.
If you’re in an office environment, if possible, turn off overhead lights and have a table lamp for softer light. If you can’t control the lighting in your environment, there are screens you can place on top of your computer screen to reduce glare. In a previous article, we highlighted how 30-second microbreaks every 20 minutes can ease physical discomfort and improve mental performance when working in front of a computer. Similar breaks also help reduce eye strain. Experts suggest looking at a distant object at least twice every hour to help prevent visual fatigue. So if you take a break every 20 minutes for brief stretching, make sure it also includes looking at a distant object to help both your eyes and body.
Winter’s not over yet. The next month or more can bring anything from ice and sleet to “Snowmageddons” and polar vortexes. Winter weather can be dangerous for you, your family, and even your pets if you’re not prepared. In the event of an emergency you should know what to do to protect yourself and your loved ones. The National Center for Disaster Medicine and Public Health has compiled a list of resources that offer information, tips, and checklists for winter-weather emergencies and general cold-weather health. Stay warm, safe, and resilient!