Welcome to the HPRC Blog. We've got lots of information here, from quick tips to in-depth posts about detailed human performance optimization topics.
HPRC Fitness Arena: Environment
It can be extra challenging to get outdoors and exercise in the winter. But don’t let cold temperatures freeze your exercise routine. Use these tips to help you “weather” the winter weather!
- 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 always can remove layers as you get warmer.
- Warm up. Take a few minutes and do a dynamic warm up before you head outdoors. This will help warm up your muscles and body, so it might feel like less of a shock when you step outside.
- Protect your extremities—especially your fingers, toes, and ears. Circulation to these areas decreases in cold weather. Chemical heat warmers also can help keep your hands and feet warm.
- 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 (negative numbers) or the temperature drops below 0°F. You’re at risk of hypothermia and frostbite if you’re not properly prepared.
- Be visible. With fewer hours of sunlight in the winter months, you might be walking or running when it’s dark out—even at dusk and dawn. Wear reflective gear or a headlamp to stay visible to oncoming traffic.
- 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 cold temperatures or stress). Talk to a healthcare professional about your concerns before heading outside for your cold-weather workout.
Food waste is a massive problem in the U.S. Billions of dollars’ worth is wasted each year—about 20 pounds of food per person each month. But there are strategies you can use to help save valuable food resources. Food waste happens along the food chain: from the farm, during transport to grocery stores and commissaries, at retail stores and food service operations, and in your home.
Military communities are working to address food waste by ordering only what’s needed, carefully planning meals, and avoiding waste through reduction and composting. In addition, many commissaries have food donation programs for items that can’t be sold but are still safe to eat. Try to do your share at home too. Read more...
Winter weather can be dangerous for you, your family, and even your pets if you’re not prepared. The next few months might bring anything from ice and sleet to “Snowmageddons” and sub-zero temperatures. In the event of a cold-weather emergency you should know what to do to protect yourself and those around you. The National Center for Disaster Medicine and Public Health has compiled a list of resources with information, tips, and checklists for winter-weather emergencies and general cold-weather health. And of course, check out the “Cold” section of HPRC’s Environment domain. Stay warm, safe, and resilient!
Compression garments come in a variety of sleeves, socks, shorts, and full-body suits. The amount of pressure, or compression, they provide depends on the type and size of the garment. Compression garments help push blood toward your heart and prevent it from “pooling” or collecting in the compressed areas. Compression sleeves also are used in clinical settings for those with lymphedema, where blood circulation is poor, or to prevent blood clots.
But can they increase your performance and decrease your recovery times? Compression garments have been shown to help blood flow to working muscles during exercise, but that necessarily doesn’t translate to better performance. Most studies look at compression socks during running, and most evidence suggests no difference in athletes’ performance levels during runs when compared to those not wearing compression socks. In addition, there’s no decrease in recovery time or blood-lactate levels.
Still, those wearing compression socks report “feeling better” and “less tiredness” in their legs during their runs. They also feel less sore following the exercise bout. And while there might not be an actual benefit of wearing compression gear, if you feel better wearing it—either during or after exercise—then keep doing what works!
Swimmers and free divers who hyperventilate before holding their breath for long periods underwater are at risk of hypoxic blackout—loss of consciousness—that can result in brain damage and death. (It sometimes is known as “shallow water blackout,” but this can be confusing because there are other causes of “shallow water blackout.”)
Hypoxic blackout often affects skilled, fit, and competitive swimmers and free divers. They practice breath holding or hypoxic training in water to increase their ability to hold their breath for longer periods of time. But depending on the technique, this can be a dangerous practice.
Breathing is a process of exhaling carbon dioxide (CO2) and inhaling oxygen. The actual urge to breathe is caused by a buildup of CO2 within your lungs. If you simply try to hold your breath underwater, the physiological urge to breathe will eventually take over so there isn’t a significant risk of “passing out.” However, some swimmers and free divers have found that if they hyperventilate before diving into the water —either by rapid breathing or taking deeper breaths—they can hold their breath for longer periods of time. It’s the act of hyperventilating that can be deadly.
When you hyperventilate before underwater swimming, the amount of CO2 is reduced in your lungs and the urge to breathe is diminished. Without warning, you can lose consciousness—at which point a breath is forced and water fills your lungs. Unless rescue is immediate, brain damage and death are likely outcomes.
Training with instructors and a skilled free-dive or swimming community will help reduce your risk of tragic accidents. In addition, there are other things you can do to avoid hypoxic blackouts.
- Don’t hyperventilate before underwater swimming.
- Never swim alone.
- Don’t ignore the urge to breathe underwater.
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!
Exercising outdoors can be uncomfortable and sometimes unhealthy when it’s hot and humid, but there are ways to work out through the weather woes. You’re more likely to breathe faster and deeper and through your mouth—bypassing your nose’s natural filtration system—on hot days. You also risk greater exposure to air pollutants (such as carbon monoxide, particulate matter, and ozone) that can inflame your respiratory system. However, the risks associated with not exercising at all are far greater than the risks of exercising outdoors.
So, plan ahead before exercising outside. And limit your exposure to pollutants, especially on days and in conditions when pollution is bad.
- Avoid exercising in heavy-traffic areas, such as along highways and during rush hour.
- During warmer months, exercise earlier in the morning or later in the evening, when ozone levels and temperatures aren’t as high.
- Check the domestic or international air-quality ratings to determine when it’s safe to exercise outside. Limit your time outside on Code Red and Code Orange days. Environmental conditions on these days aren’t healthy, especially for children, the elderly, and those with existing respiratory conditions.
- Exercise indoors when the air quality indicates high ozone and particulate levels.
- Before any demanding physical activity, limit your carbon monoxide exposure by avoiding smoky areas and long car rides in congested traffic.
More teen driving accidents happen during the summer because school is out and teens are driving more—and some are driving while distracted. If the summer sun’s shining and your teen’s asking for the car keys, hand them over cautiously. And do this only after demonstrating safe driving and discussing the danger of driving while distracted.
During the summer months, it’s estimated that 10 people will die each day as a result of accidents involving teen drivers. Distracted driving often leads to crashes. This is especially true for teens distracted by their cell phones, passengers, and other things inside their cars. Anything that takes the driver’s eyes off the road, hands off the wheel, or even mind away from driving is a distraction: Texting and using a cell phone often involves all three.
Distractions impair teens’ driving performance (regardless of their attention spans), reduce safe driving practices, and disrupt traffic flow. If your teen’s friends text and drive—and don’t see a problem with it—your teen is likely to think it’s acceptable and normal.
Discussing the dangers of distracted driving with your teen is an important first step towards prevention. And demonstrating safe, distraction-free driving yourself is key. Teens tend to think their parents are distracted while driving, sometimes more than parents realize.
As a parent, make sure to wear your seat belt, put away your phone, and concentrate on the road. Set driving rules for your teen too (for example, silencing his or her cell phone and putting it away when driving). Review the rules often, and enforce consequences when they’re broken. And ask your teen to sign the pledge, promising to be a safe, distraction-free driver.
Dumbbells, kettle bells, barbells, and benches can be expensive additions to your home gym. So, get creative, look around your home, and find common household items that can help pump up your fitness routine. Or reuse balls or bottles to boost strength and reduce waste to help protect the environment. Try these DIY home-exercise hacks for a full-body workout that’s convenient and easy on your wallet!
- Perform calf raises, single-leg raises, or squats on your stairs.
- Use a sturdy chair for tricep dips, step-ups, push-ups, or squat jumps.
- Practice ab rollers using a hand or kitchen towel on your tile or hardwood floors, or switch to paper plates for use on a carpet.
- Use a gallon (or half-gallon) jug—filled with sand to desired weight—for bicep curls, overhead presses, or tricep extensions.
- Use a 72-oz detergent bottle—weighing about 5 lbs—for 2-handed lifts such as shoulder raises or sumo squats.
- Use water bottles—filled with water or sand—for a variety of dumbbell-weight exercises, including bicep curls, weight lunges, and shoulder presses.
- Make a medicine ball: Cut a slit in a basketball or soccer ball, fill with sand, and seal.