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Heat-related injuries are a threat to Warfighters, even those in top physical condition, deployed to extreme environments. Heat acclimatization is necessary to ensure that the health and performance of Warfighters is not compromised to a dangerous degree when exposed to heat stress.
Take it slow. For unacclimatized Warfighters, physical exertion should be limited in intensity and time. Allow 9-14 days of progressive heat exposure and exertion—more for less-fit Warfighters, less for more-fit Warfighters.
Don’t overdo it; don’t underdo it! Heat acclimatization requires exposure at least two hours per day (can be two one-hour segments) while engaged in a cardiovascular exercise (which should increase in intensity each day of the acclimatization period).
It’s all relative. The level of heat acclimatization achieved is relative to the exertion normally expended by the Warfighter. If light exertion is the norm, the level of heat acclimatization after two weeks will match that. If more strenuous exertion is called for, additional acclimatization and possibly improved fitness is required.
Work smart. If Warfighters must perform physical work during the acclimatization period, take advantage of the cooler hours during the morning, evening, and night.
Stay hydrated. Adequate water is essential. Heat acclimatization increases sweating and, therefore, water requirements. Dehydration rapidly degrades safety and performance, even for those who are already heat acclimatized or in top physical condition.
For a more detailed look at heat stress and acclimatization, read HPRC’s reports on managing heat exposure.
Jack3d (sometimes known as “Jacked”) is, according to the bottle, a “powerful pre-workout supplement that increases your capacity to perform.” HPRC did an extensive search for evidence-based information on Jack3d and found that all the apparently scientific literature on the product led to its promotional website, where they offer their own reviews. Anyone taking supplements should know that there have been reports about “tainted” dietary supplements containing active ingredients of FDA-approved drugs or other compounds that are not classified as dietary supplements. But there are still testimonials, blog entries, and bodybuilding forums touting the effects of Jack3d. It’s important to know exactly what is in Jack3d and that there isn’t any information on how much of each individual ingredient is in a serving.
The label of Jack3d says that it contains 4145 mg of a “Proprietary Blend” in one scoop, with 45 servings per container. In that blend are the ingredients:
- arginine alpha-ketoglutarate,
- creatine monohydrate,
- beta alanine,
- 1,3-dimethylamylamine (geranium [stem]), and
- schizandrol A,
- as well as some flavoring and color additives.
So, what does this all mean to a consumer? There have been individual studies conducted on each of the ingredients in Jack3d. Some are more effective than others for potentially enhancing athletic performance and building muscle mass. For example, creatine may increase muscle mass and enhance exercise performance during short, high-intensity repeated exercise bouts. For more information about creatine, see HPRC’s research brief. We know that 1,3-dimethylamylamine (DMAA), a chemical from the geranium plant and also synthetically made, is used in supplements promoted for weight loss, bodybuilding, and enhanced athletic performance. According to the Natural Medicines Comprehensive Database, it’s thought to have stimulant effects. Its chemical structure is similar to that of amphetamine, and it is on the World Anti-Doping Agency’s banned substance list. No scientific literature exists on the effectiveness of DMAA for weight loss, bodybuilding, or enhanced athletic performance. Caution is advised on the use of DMAA with caffeine, since both have stimulant effects and could increase the chance of increased heart rate and blood pressure.
The amount of caffeine per scoop of Jack3d has not been released, although it has been estimated that there is less than 150 mg of caffeine/scoop. Caffeine is included on the FDA’s list as a substance “generally recognized as safe.” However, the FDA has established a maximum concentration for caffeine in cola beverages: 32.4 mg per 6 oz or 71 mg per 12 oz. Other than colas, the caffeine content of food and beverages is not regulated. The label of Jack3d states: “Do not use in combination with caffeine or any stimulants from other sources whatsoever, including but not limited to, coffee, tea, soda and other dietary supplements or medications.” Caffeine seems to increase physical endurance, but it does not seem to affect activities that require high exertion over a short period of time, such as lifting.
The main issue with Jack3d is the same one that exists with many bodybuilding products on the market. There is no way to judge the interaction between the ingredients, especially when the consumer is unable to determine how much of each ingredient is in the product. This product contains multiple ingredients and, potentially, additional and potent ingredients not listed. It also could be contaminated, as has been seen with many other supplements. The FDA has put together information on tainted products promoted for bodybuilding.
It is important to mention that Jack3d comes with serious warnings on its label. As with any supplement, be educated, be advised, and consider all the unknowns before you decide whether the possible benefits are worth risking your health.
The Health section of the New York Times published an article that discussed a new study recently published in The Journal of Applied Physiology. Researchers found that some athletes warm up so much that they are too tired to perform at their best during competition. Researchers at Canada’s University of Calgary studied highly trained male track cyclists, asking them to compete, first, after their usual warm-up (20 minutes of riding, increasing to 95% maximum heart rate, then 4×8 minute all-out sprints) and, second, after a 15-minute, lower-intensity warm-up.
Interestingly, they found that the cyclists’ muscles had more power before the their usual warm-up than after it and that they performed better after the less intense warm-up than after their usual warm-up. Researchers concluded that when warming up, less may be more.
Fruits & Veggies — More Matters™ is a health initiative led by The Centers for Disease Control and Prevention (CDC) and Produce for Better Health Foundation (PBH), to increase daily consumption of fruits and vegetables. Visit the CDC and PBH websites for helpful tips, recipes, and interactive tools to help you increase your intake of fruits and vegetables.
Probiotic products were seized by U.S. Marshals after the Food and Drug Administration (FDA) complained that the products were marketed as drugs. The company who sells the probiotic products claims that the products will prevent or treat disease, which is in violation of the Federal Food, Drug, and Cosmetic Act. More information is provided in the FDA News Release.
NBA superstar Shaquille O'Neal recently announced that he will retire from professional basketball after 19 seasons and four championship rings. In addition to that announcement, O'Neal announced via a YouTube video that he, like 12 million other Americans, had been diagnosed with sleep apnea.
According to his girlfriend, the seven-feet-tall, 300-plus-pounds center snored excessively during the night, and she noticed that his chest would often cease movement entirely. After participating in a Harvard University–sponsored sleep study he was diagnosed with a mild case of sleep apnea and was advised to begin wearing a CPAP (Continuous Positive Airway Pressure) mask, a respiratory ventilation therapy that assists the wearer’s breathing while asleep. O'Neal's story has a happy ending—because of the recent diagnosis and subsequent treatment, O’Neal reports that he feels more energetic and that his overall quality of life has improved. He is also happy and comfortable with the treatment. Other professional athletes suffering from sleep apnea have not been so fortunate. In 2006, Reggie White, defensive end for the Philadelphia Eagles and Green Bay Packers—one of the greatest players in football history—reportedly died from causes related to sleep apnea.
What exactly is sleep apnea? And how does it affect athletic performance? People with untreated sleep apnea stop breathing repeatedly during their sleep, sometimes hundreds of times during the night and often for a minute or longer. According to the American Sleep Apnea Association, there are three types of apnea: obstructive, central, and mixed. Of the three types, obstructive sleep apnea (OSA) is the most common. Weight can contribute to sleep apnea. In 2009, a study by Sweden's Karolinska Institute showed that overweight and obese men who lost weight during a calorie-restricted diet over nine weeks had major improvements in their sleep apnea symptoms.
Other risk factors for obstructive sleep apnea include certain physical attributes, such as having a thick neck (which describes many athlete body types), deviated septum, receding chin, and enlarged tonsils or adenoids. Allergies or other medical conditions that cause nasal congestion and blockage can also contribute to sleep apnea.
Signs of sleep apnea include loud and chronic snoring, choking, snorting, or gasping during sleep, long pauses in breathing, and daytime sleepiness regardless of how much time you spend sleeping. Other common signs and symptoms of sleep apnea include waking up with a dry mouth or sore throat, morning headaches, restless or fitful sleep, insomnia or nighttime awakenings, going to the bathroom frequently during the night, waking up feeling out of breath, forgetfulness and difficulty concentrating, moodiness, irritability, or depression.
Untreated, sleep apnea can cause high blood pressure and other cardiovascular diseases, memory problems, weight gain, impotency, and headaches. Moreover, left untreated, it may be responsible for job impairment and motor vehicle crashes.
In terms of athletic/sports performance, sleep apnea is a major concern because sleep apnea causes a disruption to healthy sleep patterns, which in turn can affect physical performance. According to a 2007 Stanford University study of sleep and athletic performance, athletes who extend the amount of sleep they get and reduce their sleep debt are more likely to improve their performance. Conversely, if an athlete does not get a good night’s sleep, then the next day he/she is tired, sleepy, or irritable. In such cases, physical performance also is impaired, since there is limited energy reserve due to the lack of adequate or good-quality sleep. Sleep apnea not only has an impact on athletes—it affects the military, as well.
So what can you do if you suspect that you or your sleep partner has sleep apnea? The only way to be sure is to undergo a sleep test, which is done in a sleep lab where patients sleep in a special bedroom with electrodes and other sensors attached to various parts of the body. There, you will be monitored throughout the night to keep track of whether and how often you stop breathing, how low your O2 sat (oxygen saturation) goes, and what your brainwaves are doing while you're sleeping.
For additional resources on sleep and sleep apnea, please visit the following:
Research at USARIEM (U.S. Army Research Institute of Environmental Medicine) was featured in a article by writer Christopher Solomon titled "G.I. Joe and the House of Pain" in a special issue of Outside Magazine about human performance. The author spent time in the research lab's heat chamber, altitude chamber, and cold-water pool—conditions that simulate the extreme environmental conditions found in theater. He interviewed research physiologists there about USARIEM's work over the past 50 years as well as its current studies, all of which address the crucial issues of Warfighter health and performance in extreme environments.
Several weeks ago we started a series on strategies for processing emotions. We have described four "savoring" strategies and four "dampening" strategies. Using more of the savoring strategies and fewer of the dampening strategies can help positive feelings linger from positive experiences. But you must also make sure you use strategies that match your personality and lifestyle. In this research study, those who used multiple savoring strategies (and avoided more of the dampening strategies) were the happiest. The authors also suggest staying in the moment when something positive happens to you and once the moment has passed, stepping back and savoring the experience. Take a moment now to review the tips from weeks one, two, three, and four.
The United States Department of Agriculture (USDA) released MyPlate as the new Dietary Guidance graphic. MyPlate replaces the Food Guide Pyramid and is split into five sections for fruit, vegetables, grains, dairy and protein. The new recommendations focus on the importance of eating fruits and vegetables (half a “plate”). Go to www.ChooseMyPlate.gov for the new graphic and recommendations. For the USDA press release issued about MyPlate,