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HPRC Fitness Arena: Physical Fitness
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.
The physical demands of military life are challenging, and if you’re not prepared, they can lead to injuries. The injury prevention series we’ll be running over the next several weeks will provide you with information and strategies for preventing some of the most common injuries: those to the knee, ankle, rotator cuff, back, iliotibial band and wrist/hand. Prevention is key: Taking time for the small stuff may have big payoff down the road. Much of what the exercises done for recovery after an injury can actually be done to prevent the injury in the first place. Stay injury-free for optimal performance! Check back soon for the first in this series.
Have you ever wondered why people who do the same resistance training workouts day after day aren’t getting the results they want? The goal of resistance training is to create an “adaptation response”—that is, to get your body to change in response to the demands. Once your body has adapted to a specific training program, you need to change the demands you place on it. If you don’t, you’ll find yourself eventually reaching a plateau where you don’t make any more gains—or sometimes even lose progress. One way to avoid this common training mistake is to implement “periodization”—the systematic shaking up of your routine (intensity and numbers of sets and reps). This method can optimize your training gains and minimize the risks of overtraining and injury. Implementing these training routines requires a strength training expert, so make sure you seek assistance. For example, the Army has implemented a new program for Master Fitness Trainers. And for more information on strength training, check out the HPRC’s Performance Strategies for Muscular Strength.
The dietary supplement and fitness industries are filled with sport drinks, powders, bars, pills, gels, footwear, clothing, and an array of devices all claiming to provide you with a competitive advantage, whether it be improved performance or enhanced recovery. With the ever-growing popularity of team and individual sports, professional and recreational athletes of all ages are an easy target for these claims. But how many of these claims are backed by evidence-based research?
A recent report now reviews the quality of evidence behind the claims of improved sports performance made by advertisers for a wide range of sports-related products, including sport drinks, supplements, footwear, and clothing. The team identified 431 performance-enhancing claims for 104 products advertised in more than 100 general, sport, and fitness magazines in the UK and U.S. for a single month in 2012. They found that more than half of the advertisements and their associated websites provided no evidence to support the claims of enhanced sports performance. Only 146 references were found, and only 74 of these met basic criteria for research quality and almost all of the 74 were found likely to be biased or lacking scientific objectivity. Only three studies were rated as “high” quality and probably unbiased. Such lack of evidence makes it very difficult for consumers to make well-informed decisions about using performance-enhancing sports products.
This review makes it clear that many of the claims made for sports and fitness products lack reliable evidence to support them and that more and better studies are needed to help inform consumers. In the meantime, consumers should be cautious when reading claims of enhanced performance and recovery and always remember that “true” evidence-based results mean that a substantial number of independent research studies have been performed, with findings that clearly support the claims made by advertisers. Presently, there is still no substitute for sound physical conditioning and nutrition practices.
For more information on dietary supplements and how to choose supplements safely, please visit Operation Supplement Safety (OPSS). For information on physical fitness and conditioning, please explore HPRC’s Physical Fitness domain. The original British Medical Journal open-access article is available online.
Attention, all disabled service members and veterans! Staying active helps with recovery by rebuilding strength and endurance—and in so many other ways, as well. A positive mindset and a supportive community are as important as fitness, and getting involved sports such as snowboarding, cycling, wheelchair basketball, and others can build both physical fitness and mental resilience. Consider checking out the Warfighter Sports Program developed by Disabled Sports USA. It offers more than 30 winter and summer adaptive sports in more than 150 events nationwide. Instruction, equipment, and transportation are provided to Warfighters and their guests. Become a part of the team and find the events happening in your area today!
For older men, it’s especially important to lead a healthy and physically active lifestyle since the risk for certain chronic diseases increases with age. Multiple studies have found that as little as 30 minutes a day of moderate- to vigorous-intensity exercise can significantly lower a man’s risk for heart disease and related risk factors such as diabetes, high cholesterol, and high blood pressure. Age is also a significant risk factor for developing prostate and colorectal cancers, which makes prevention and risk-factor management even more important for older men.
Exercise has been linked to lower risk and rates of death for prostate, lung, and colorectal cancers, the three most common cancers experienced by men. So get out there! Take a brisk walk, go for a jog, swim, bike, play tennis, even certain heavy outdoor yard work is acceptable for this purpose. If you need more structure, try a gym—many fitness centers offer military discounts on memberships and personal training sessions. Some military facilities also offer group and family recreational activities. The important thing is to find an exercise routine that you enjoy. If it’s not fun or motivating then it’s not likely to become part of your lifestyle.
The benefits of an active lifestyle are numerous, but prevention is one goal to keep your regular exercise program on the right track. Be sure to consult with your physician before starting an exercise routine, especially if exercise is new for you. Living a healthy lifestyle and getting screened for health complications are important ways to maintain readiness, resilience and optimal performance.
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.
Operation Live Well is a new wellness campaign by the Department of Defense that aims to make healthy living the easy choice and the norm for service members, retirees, DoD civilians, and their families. They point out resources for how to eat better, stay physically active, quit or avoid tobacco, and stay mentally fit. The educational, outreach, and behavior-change initiatives provide tools and resources to help you learn about healthy lifestyles. You’ll also be able to develop your own personalized health plan via the Operation Live Well website soon.
A second part of Operation Live Well is their Healthy Base Initiative (HBI), which aims to help the defense community reach or maintain a healthy weight and avoid tobacco use. Scheduled for launch during the summer of 2013 at 13 military installations and DoD sites worldwide, HBI will offer a range of installation-tailored, health-related programs that will be measured for their effectiveness. The programs that are most successful will eventually be expanded to other installations.
For more information on Operation Live Well, visit militaryonesource.mil/olw.
If you’ve injured a muscle or tendon during your PT training and wondered if that elastic tape that comes in bright colors could help you, read on. Elastic therapeutic tape is significantly different from regular elastic bandages, and it became popular during the 2008 Beijing Olympics when athletes such as professional beach volleyball player Kerri Walsh used it. Both are used to treat athletic injuries such as strains and sprains, but they produce their benefits in different ways. Elastic therapeutic tape is made of a thin material with thickness and elasticity similar to that of human skin. When taped on skin it supports injured muscles. However, it has also been reported that it helps relieve pain by lifting the skin away from the tissue beneath and enhancing blood and lymph flow to the injured area. Regular elastic bandages such as ACE bandages also provide support and reduce pain when wrapped around an injury, but unlike elastic therapeutic tape, they provide localized pressure to reduce swelling. In addition, they don’t stick to skin and usually restrict range of motion. Users report that elastic therapeutic tape works, but scientific evidence is contradictory. There just isn’t enough evidence to support the use of elastic therapeutic taping over other types of tape/bandage, and there is no scientific explanation for why it should work. So just be aware and use this tape at your discretion.