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HPRC Fitness Arena: Environment
Can you train in the heat to improve your performance at altitude? The answer is “sort of.” “Cross acclimation” or “cross tolerance” is the idea that exposing yourself to one environmental condition can help you adapt to another one as long as they have certain things in common.
As it turns out, this is the case for heat and hypoxia (low oxygen). This is important because athletes and service members can be exposed to altitude without prior or sufficient acclimatization. Altitude sickness can cause several problems, especially decreased performance. But some evidence shows that this method of training in hot conditions to prepare for altitude can actually work.
If you climb to the top of a mountain, there’s less air and less pressure. And you’re getting less oxygen with each breath. This can be simulated at sea level (in special labs) where pressures are normal, but the amount of oxygen in the air is reduced (fake altitude).
However, there’s a bit of a catch. Training in the heat under artificial low-oxygen conditions—normobaric hypoxia or “fake altitude”—involves normal pressure, which is different from “real altitude” or hypobaric hypoxia, which involves reduced oxygen at low pressure. The difference is in the pressure.
So, do these two environments cause the same types of physiological changes? There are several other factors involved in real-altitude acclimatization that might not be accounted for at fake altitude, so the jury’s still out.
Training in the heat might prepare you for performance at altitude—to a point. Ideally, if you’re going to be at altitude, try to acclimatize yourself as much as you can.
There are “steps” you can take to protect your feet from blisters. Common among athletes and service members, they might seem like a minor nuisance. However, if left untreated, they can lead to serious infections, sepsis (blood infection), and knee, ankle, or hip injuries.
Blisters result from a combination of friction and moisture. They’ve been blamed on shoe fit or lacing style, but scientific research has shown this isn’t necessarily the case. Common remedies—such as applying antiperspirant or drying powders to the bottom of the foot—aren’t very effective. And in some instances, they can cause irritation, increasing your chances of developing more blisters.
So if friction and moisture are causing problems, then wearing proper socks can bring relief. Look for ones made from acrylic fibers or materials other than cotton, which tends to stay wet. Synthetic materials (nylon, neoprene, and polyester) reduce the amount of shoe-to-sock and sock-to-foot friction by wicking moisture away from your skin. Padded socks also help because they allow for movement within the yarn, reducing frictional forces.
Some evidence suggests wearing a synthetic nylon or polyester liner with an outer-padded wool sock can help prevent blisters. Tip: Try finding your ideal sock before buying boots or shoes because the added bulk might affect the shoe size you need.
You also can reduce your risk of blisters by planning ahead, especially on extremely hot or rainy days. Avoid puddles. Remember to bring an extra pair of socks too. And avoid pouring water on your head since it can drip down into your shoes. Keep your feet happy and blister-free.
Skin cancer is the most common form of cancer in the U.S., but with proper precautions you can decrease your risk considerably. The sun releases invisible ultraviolet (UV) radiation, which can cause cataracts (clouding of the eye lens) and skin cancers. An estimated 63,000 new cases and 9,000 reported deaths from melanoma—the deadliest form of skin cancer—occur each year.
UV rays also cause tanning and sunburns—and can damage your skin after only 15 minutes of exposure. They weaken the skin’s elasticity, causing wrinkling, rash, and freckles too.
Remember that you can get sun damage on sunny and cloudy days. UV rays penetrate clouds, exposing you to 80% of the sun’s harmful effects. The good news is that you can take steps to protect yourself from UV rays, while enjoying the outdoors.
- Limit your time in the sun. Seek shade and try to avoid sun exposure during midday (10 a.m. to 2 p.m.) when the rays are strongest. And avoid suntanning and burning.
- Cover up. Wear protective clothing, including hats, long-sleeved shirts, and pants when going outdoors. Remember that protection decreases when clothes are wet.
- Apply sunscreen. Use water-resistant sunscreen with Sun Protection Factor (SPF) 15 or higher. Apply and let it absorb 15–30 minutes before heading outdoors. Use lip balm with SPF 30 or higher to protect your lips too. Reapply every 2 hours or after swimming, sweating, or toweling off.
- Protect your eyes. Wear sunglasses to cover the skin around your eyes and help prevent eye damage. When choosing sunglasses, check the label to make sure they block 100% of UV rays.
Good eye health is critical to your performance. The National Eye Institute (NEI) recommends maintaining a healthy lifestyle to keep your eyes strong and prevent vision damage. There are ways to help protect your eyesight.
- Get your eyes checked regularly.
- Wear protective eyewear (such as goggles and/or sunglasses).
- Limit staring at your smartphone.
- Avoid “computer eyes.”
- Learn about potential vision problems that can result from traumatic brain injury.
Whether you’re suffering from any eye injuries or conditions, or just have questions, check out the Vision Center of Excellence website for helpful resources. You can find eye-care providers there too.
And download the NEI’s Healthy Vision Month Fact Sheet to learn the 5 steps you can take to protect your vision.
The truth is that the jury’s still out on whether running on a softer surface has less impact on joints and muscles. Some research suggests it might not actually matter, and the forces that impact your lower body on various surfaces such as asphalt, concrete, and grass don’t increase knee pain or injury risk. One explanation is that your body automatically adapts to the surface you’re running on. That means you’ll instinctively strike harder on softer surfaces, and strike softer on harder surfaces. On the other hand, some evidence suggests that running on softer surfaces (such as grass) reduces stress on your muscles and joints.
“But it feels better when I run on soft surfaces,” you might say. That difference in feeling is likely due to the different kinds of muscles, or stabilizers, you use when running on softer surfaces, which creates a sensation of less impact, although the overall impact on your body is the same.
That’s not to say that you shouldn’t run on soft surfaces if it makes you feel better. Feeling better on a run goes a long way. However, softer surfaces such as trails, grass, or sand tend to be more uneven, which can pose a greater risk of strains and sprains.
When it comes to injury prevention and recovery, it’s also important to consider other factors such as wearing the right running shoes. And be sure to increase your running intensity and volume gradually to help avoid injury too.
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.
Mother’s Day is set aside to honor mothers, but for service members who can’t celebrate with their moms or who can’t take time to celebrate being a mom, it can be hard. But still do your best to take time and recognize the special moms in your life.
- Show your appreciation with a handwritten note or ecard. If you’re feeling creative, make a card from scratch—just like you did as a kid—and drop it in the mail.
- Enjoy a physical activity together. Go walking, running, biking, hiking, or do yoga. Maintaining a healthy lifestyle, together or apart, can help you both enjoy Mother’s Day in the future too.
- Nourish your mom with healthy treats or a homemade meal. And consider inviting a mom who doesn’t have family nearby. Good food and conversation can make her day special too.
If you can’t be with your mom, then schedule a time to talk or video chat. Let her know how much you cherish your relationship. And ask any questions you might have wondered about, such as:
- How are we alike or different?
- What did you really think when I joined the military (or married someone in the military)?
- Is it easier being a mother now that your kids are grown?
- What do you hope the next few years will bring for our family?
If you’re feeling some sadness or anxiety, make a point to manage your stress. “Perfect” moms and/or children could evoke stress, even if you love them dearly. Consider mindfulness or other ways to cope, and make the best of this day.
Happy Mother’s Day to all military moms—service members, spouses, and mothers of service members!
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.
Many service members exposed to bomb blasts in the field walk away unscathed—or so it would seem. However, there could be some damage they’re not “seeing.”
High-pressure shockwaves from explosive blasts can cause serious eye trauma. In fact, up to 10% of all blast survivors experience significant eye injuries from projectiles thrown into their eyes, eye perforations caused by the high-pressure blast waves, or effects on the eyes associated with traumatic brain injury (TBI). If you were exposed to a blast while in the field but weren’t otherwise injured, don’t wait to set up an appointment with your eye doctor. Prompt medical attention could prevent permanent injury.
Most eye injuries are preventable if you wear protective eyewear on-duty and off-duty. There are many options to choose from the Department of Defense’s (DoD) approved Authorized Protective Eyewear List (APEL). Your vision is extremely important! For more information on protecting your eyesight, visit the Vision Center of Excellence.
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.