Filed under: Exercise
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.
Regular physical activity can make you sleep better—but how close to bedtime should you exercise? While the general opinion has been that vigorous exercise within three hours of bedtime might negatively affect your sleep, new research is reexamining this belief. Some preliminary studies have found that exercise before bed (both moderate and vigorous) didn’t negatively impact sleep quality. However, more research is needed to better understand truly how exercise closer to bedtime can impact sleep. Remember—there are many factors that contribute to a good night’s sleep. Just be aware that if you exercise in the evening, it might affect how well you sleep at night. Check out HPRC’s Sleep Optimization section for additional information.
If you’re going TDY soon and your travel plans include an airport, read on. Don’t just step on to the people movers between concourses and then sit around while you wait. The American College of Sports Medicine (ACSM) wants you to turn your travel experience into an opportunity to get some exercise. ACSM’s “Exercise on the Fly” task force is promoting healthy air travel by getting people to think of airports as fitness centers: Every major airport is climate-controlled, with stairs and long stretches of walking areas. For layovers that last several hours, you might even have time to find a park or gym nearby outside the terminal. The task force is working with airport officials to post signs and other materials that promote walking while you wait. They also hope to publish a list of all physical activity opportunities at about 20 major hub airports in the United States. Remember that every little bit counts, even if it’s just a brisk 10-minute walk between terminals. So next time you head to the airport, be sure to throw a pair of sneakers in your carry-on for a workout on the go.
Reports estimate that one of every four deaths is attributed to heart disease. Cardiorespiratory (aerobic) activities such as jogging, cycling, and swimming directly improve the function of the heart, which decreases the risk of coronary artery disease, high cholesterol, high blood pressure, stroke, and type II diabetes. Aerobic fitness is important enough that all active-duty service members must complete an aerobic fitness assessment, such as a maximal effort timed run, as part of their annual physical fitness test.
To delve a little deeper about the changes your heart, lungs, and blood vessels undergo when you improve your aerobic fitness, read on. One important change that occurs is that your heart’s “stroke volume”—the amount of blood the heart pumps out with each beat—increases. This comes from an increase in your heart’s strength and ability to hold a greater amount of blood. This in turn reduces your heart rate (HR) both at rest and at all levels of exercise. In fact, with consistent training, your resting HR could likely decrease as much as eight to10 beats per minute. That’s about 5 million fewer heartbeats in a year! Simply put, aerobic training means your heart has to do less work to get your job done.
Changes also occur to your blood and blood vessels with aerobic fitness. Your blood vessels increase in diameter and are better able to expand and constrict. This allows blood to move through your blood vessels with less resistance, reducing your blood pressure. And what happens to your blood? The levels of plasma (the liquid portion of the blood), red blood cells, and hemoglobin all increase, which means that your blood can carry more oxygen.
Altogether, the physiological changes mentioned here should make it easy to see why aerobic exercise is so important. If you want to learn more about how to get started improving your cardiorespiratory health through exercise, visit these Performance Strategies from HPRC.
If you want improve your PFT and/or CFT score then try performing a dynamic warm up before the test. While there is still much debate around a pre-exercise warm-up, a recent review of the literature specific to military testing found that dynamic warm-up and dynamic stretching might improve your fitness test performance. Overall, dynamic warm-ups appear to improve pull-ups, push-ups, power, flexibility, and aerobic performance. In addition, prior to the dynamic warm-up, an aerobic warm-up such as about five to 10 minutes of light jogging, swimming, or cycling sees to have an overall beneficial effect on cardiovascular assessments such as sprinting and running. On the other hand, static stretching (the kind you stretch and hold) appears to have a negative effect on exercise performance in trained populations. If range of motion is needed, then static stretching might be the most beneficial type of warm-up. Most services no longer test for the sit-and-reach, but there are some commands that continue with this testing modality. While nothing will help you more than properly training for your fitness assessments, doing the little things on testing day may help you achieve peak performance.
The purpose of the 2011 Department of Defense Health Related Behaviors Survey of Active Duty Military Personnel (HRB) is to assess the health practices of active-duty service members. Substance abuse, mental and physical health, and lifestyle choices are important matters, especially when you need to be at your best for the demands of military life. Certain areas of this study directly affect human performance, and results (as reported in the Executive Summary) show that health behaviors vary between services.
Physical Activity/Body composition
Here are some figures from the Physical Activity/Body Composition portion:
- Overall, service members have lower rates of obesity (as defined by BMI) compared to the general public.
- More than one-third of active-duty service members age 20 and older were considered to be at a healthy weight, which exceeds the Healthy People goal as well as civilian population estimates.
- 75% of active-duty members practiced moderate to vigorous physical activity in the 30 days prior to the survey, with Army and Navy personnel having the highest rates.
- Almost half of service members do strength training three or more days a week.
Physical health and fitness are key components to optimal fitness. While these numbers are encouraging, there is no doubt that a larger portion of the military should be at a healthy weight and fit enough to fight. Make fitness and weight management your priority for performance.
- Only 40% of all active-duty personnel surveyed get the recommended seven to eight hours of sleep per night.
Sleep is an important factor in recovery. Poor sleep habits can take a physical and mental toll on your health, your relationships, and your performance.
Tobacco and alcohol
One area where the military could improve is in the use of tobacco products and alcohol:
- Almost one-quarter of service members reported smoking a cigarette in the 30 days prior to taking the survey, which is higher than the civilian population and the Healthy People objective.
- Smokeless tobacco use is also prevalent in the military with 12.8% of all service members using smokeless tobacco in the month leading up to the survey.
- Rates of binge drinking were higher in the military than in the civilian population and more prevalent in the Marine Corps than in any other branch.
Tobacco in any form is detrimental to your health. If you’re thinking about quitting smoking or would like to talk to someone about your alcohol use, there are lots of resources and professionals that can help you achieve your goal.
Stress and mental health
After more than a decade of ongoing war, troops have—and will continue to experience—significant mental stress as a result of their service. In general, 5-20% of service members reported high rates of anxiety, depression, PTSD, and/or other mental health concerns.
- The most common military-related sources of stress were being away from family and friends and changes in workload but included financial problems and family members’ health problems.
- Women reported experiencing personal sources of stress more often than men did.
- Those who drank heavily were more likely to report problems with money and relationships.
Drinking, smoking, overeating, and even attempted suicide are all negative coping factors when dealing with stress. The survey found that the most effective methods of coping were planning to solve problems and talking with friends or family members. Find out how to use productive and effective methods for coping with stress and mental health.
Nutrition and dietary supplements
Being fueled to fight is an important component for anyone in the military. Proper nutrition requires consuming healthy—and avoiding bad and potentially harmful—foods and beverages.
- According to the survey, active-duty personnel eat too many unhealthy foods such as snacks, sweets, and sugary drinks and not enough of the recommended servings of fruits and vegetables.
- More than one-third of personnel reported daily dietary supplement use.
What you decide to put in your body now may affect your performance and your career later. For more information on nutrition for combat effectiveness, read Chapter 15 of the Warfighter Nutrition Guide. And make sure you know what you’re putting into your body. Dietary supplements are not subject to pre-market approval by the FDA, and there are many ingredients that may do more harm than help. You can learn more about dietary supplements at Operation Supplement Safety. And for more information about the Health Related Behavior Survey, visit TRICARE’s webpage.
Deployments, injuries, transitions—just a few of the many things that can interfere with your normal exercise routine. Too long a break and your cardiovascular—or aerobic—fitness may suffer. For optimal performance, however, getting your heart and lungs back in action is critical. If you’ve been away from your routine for a while, start slowly and gradually increase intensity and duration. Be patient and stick with a routine, even on days you don’t feel like it. Mix up your routine when you’re able with different types of aerobic exercise such as biking, running, swimming, and rowing. For help planning your comeback, check out HPRC’s Performance Strategies for Rebuilding Cardiovascular Fitness. If you’d like to learn more about aerobic conditioning specifically for the PRT/PFT, read part 1of our training series.
Neck pain in military pilots, particularly helicopter and fighter jet pilots, is a major concern. Conditions inherent in flying helicopters and jets put these pilots (and crew) at a greater risk for developing neck pain due to misaligned postures, the use of additional equipment on their helmets, and exposure to high G-forces. Effectiveness and readiness are compromised if a pilot is can’t fly because of pain. Pilots sometimes forego medical treatment for fear of being grounded or losing their flight status and, as a result, pain is left untreated.
Exercise programs specifically for strengthening the neck area can be helpful in preventing pain. “G-warmup” maneuvers can also be beneficial to prepare a fighter pilot for high G-forces. Military researchers are looking at improving and updating the ergonomics of aircraft seats and cockpits, as well as helmet fit. In the meantime, see your doctor if your neck pain doesn’t improve with rest and basic at-home treatments. And for more information, read HPRC’s InfoReveal.
Looking to define your glutes, hips, and thighs? Want a total body workout to help you improve your score on the next PFT? Not close to your unit? You can access workouts complete with warm-up, cool-down, and videos of each exercise all online. There is a variety of routines, so depending on what you are looking to get out of a workout, there may be one for you. This is a handy resource for all Warfighters, but reservists and National Guardsmen often can’t work out with their unit, so these videos could provide a new twist to an individual workout. If you are far from your unit and are not able to participate in unit physical training, try these workouts! Sport-specific workouts are also available for the cyclists or swimmers in the service.
Previously HPRC reported on how much physical activity healthy adults need. This week, the spotlight’s on children and teenagers—and whether they’re getting the exercise they need.
According to the Physical Activity Guidelines for Americans, children and adolescents need at least 60 minutes of physical activity every day, including:
- Aerobic exercise for most of the 60 minutes. Most days can include either vigorous-intensity activities (such as running, swimming, and jumping rope) or moderate-intensity activities (such as walking or skateboarding), but at least three days a week it should include at least some vigorous-intensity exercise. Check out Let’s Move! for ideas on how to get active as a family.
- Muscle-strengthening activities such as playing tug of war, exercising with resistance bands, or climbing on playground equipment. Strengthening exercises should be done at least three times a week. For safety guidelines on strength training for children and teens, check out this article from HPRC.
- Bone-strengthening (impact) activities such running, jumping rope, basketball, tennis, and hopscotch. Impact activities strengthen bones and promote healthy growth and also should be done at least three times a week.
For more ideas on moderate- and vigorous-intensity aerobic activities, as well as muscle-strengthening and bone-strengthening physical activities, check out the table in Chapter 3: Active Children and Adolescents of the Physical Activity Guidelines. For more ideas on getting fit as a family check out Let’s Move, a comprehensive initiative by the First Lady. For military-specific resources, check out HPRC’s Family & Relationships domain.