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HPRC Fitness Arena: Physical Fitness
Conventional wisdom suggests that running on softer surfaces is better for the body than harder surfaces. However, in a recent New York Times article, the subject of running injuries on hard versus soft surfaces was examined. Exercise physiologist Hirofumi Tanaka of the University of Texas at Austin took a deeper look at soft-surface running and said he could not find any scientific evidence that a softer surface benefits runners. Tanaka developed an interest in the topic after experiencing a running injury. When he was recovering from a knee injury, an orthopedist told him to get off the roads and hit the trails. He took that advice and twisted his ankle and aggravated the injury while running on the softer, irregular surface.
In the aftermath of his accident, Dr. Tanaka said he could not find scientific evidence supporting that a softer surface is better for runners than a hard one, nor could other experts he queried. In fact, he suggested that it makes just as much sense to reason that runners are more likely to get injured on soft surfaces, which often are irregular, than on smooth, hard ones.
Stars and Stripes reported that the Navy has made changes to its Physical Readiness Program. According to the article, if sailors are unable to meet body fat standards, it will result in an overall failure of the physical fitness assessment, and they will not be allowed to take the rest of the physical fitness test.
The Navy’s move is similar to the Army’s revision of its own training program to deal with overweight and unfit recruits. Navy sailors will be required to meet the body composition guidelines and will be rated on a new five-tier scale of outstanding, excellent, good, satisfactory, or failure.
In a recent Healthy Tip, we briefly described a notable article in the June 2011 New England Journal of Medicine about long-term weight gain. The 20-year study involved more than 120,000 healthy men and woman of normal weight. All were examined at four-year intervals and were found to have gained an average of almost a pound a year. That doesn’t seem like much—unless you consider that if you’re a fit 160 pounds at age 30, you’ll have put on 20 pounds by age 50. At that point your extra weight may be compounded by diabetes, bad joints, heart disease, and perhaps even cancer—all of which are associated with obesity. So now you’re forced to find ways to lose weight.
Wouldn’t it have been better to maintain a healthy weight all along? Some of the study’s observations regarding food choices and exercise might prove helpful in maintaining your weight as you age.
The study found that some foods were significantly associated with weight gain: potato products such as potato chips and French fries, sugary beverages (sodas, for example), red meat, processed meat products, and refined grains. On the other hand, foods associated with no weight gain were vegetables, whole grains, fruits, nuts, and yogurt.
Other factors found to be associated with weight were physical activity (increase = no gain in weight); alcohol consumption (increase = weight gain); sleep habits (less than six or more than eight hours per night = weight gain); and TV habits (more TV = weight gain), a correlation that seemed partly due to more snacking (Superbowl, anyone?) and less activity.
A single change in diet or lifestyle had less effect than several together. It makes sense that if you exercise less and eat more foods associated with weight gain, you’ll gain weight more easily than if you exercise less but still eat well.
Why some foods seem to contribute to weight gain more than others is still not fully understood, but it probably has a lot to do with what makes us feel satisfied when we eat. High-calorie food and drink that go down fast and easy and quickly enter our bloodstream may not make us feel full when we consume them, so we tend to eat more of them. High-fiber foods like fruits and vegetables fill us up and are low in calories. Even high-fiber nuts, which tend to have a lot of calories, are associated with no weight gain, perhaps because they satisfy us and keep us from eating candy and cake that do cause weight gain. Yogurt is an interesting case, since there has been a lot of interest lately in probiotics (bacteria felt to contribute positively to our health). Perhaps yogurt changes the bacterial flora in a way that contributes to weight stability and loss.
The reason we discuss this study in more depth is twofold. First, it highlights the fact that Americans have a tendency to gain weight as they get older. Knowing that, we can be vigilant of what we eat and how active we are in order to help prevent this weight gain. Second, it warns us of the most common food offenders to avoid—and those to embrace—and underscores the concept that weight is a balance between the calories we consume (foods and beverages we eat) and the calories we expend (physical activity). Make sure you find the proper balance when you’re young, so you won’t be overweight—and perhaps sick—when you’re older.
Calisthenics have long been a basic component of Warfighter training to increase strength. They require minimal equipment and space and can be done virtually anywhere. Common calisthenic exercises include push-ups, pull-ups, sit-ups, dips, and squats. They help develop and maintain muscle strength, endurance, and power as well as flexibility. There are many ways to customize a calisthenic routine to achieve a specific fitness goal. For example, performing a low number of repetitions with added resistance will effectively increase muscle strength. Training with a buddy is a great way to provide resistance. Muscle endurance, on the other hand, requires a routine with a lot of repetitions. It’s recommended to include two calisthenic sessions each week on nonconsecutive days, along with other forms of physical training (e.g., plyometrics, strength training, or aerobic training). A 30-minute calisthenic session should consist of one to three exercises that involve multiple muscle groups.
For more detailed information on calisthenics, go to Chapter 8 of The Navy SEAL Physical Fitness Guide.
Muscle strength is an essential component for successful Warfighter performance. Developing optimal muscle strength and endurance maximizes job performance and reduces risk of injury. The FITT principle can help you achieve this goal. FITT refers to “frequency, intensity, time (or duration), and type” of activity.
- Frequency is the number of sessions in a week that an individual trains. At least two days per week of strength training is recommended.
- Intensity, considered the most important aspect of strength and endurance conditioning, is defined by the amount of weight used per repetition. For muscle endurance, training should involve 20-60 repetitions of 30% to 50% of one repetition max (1RM; the maximum amount of weight one can lift for one repetition) per set. For muscle strength, training should involve 1-12 repetitions of 65% to 90% of 1RM per set.
- Time of sessions should range from 30 to 60 minutes.
- Type of exercise should vary in strength and conditioning routines to prevent boredom and improve gains. A combination of free weights and machines is recommended.
For more detailed information on strength training, read Chapter 6, Strength Training, of The Navy SEAL Physical Fitness Guide.
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.
The Human Performance Resource Center (HPRC) was quoted in a recent article in the Courier-Journal (Louisville, KY).
The article discusses the impact of older active duty military personnel and military readiness.
Maintaining a physically fit body requires consistent training and motivation. It’s common for individuals to get stale or fall into a training rut. Consider cross-training, adding new activities and exercises, or just doing something physical for fun!
The Department of Defense (DoD) and American College of Sports Medicine (ACSM) convened a workshop at the Uniformed Services University in Bethesda, MD, that examined various aspects and issues of high-intensity training (HIT) programs—now referred to as Extreme Conditioning Programs (ECPs).
The executive summary of the workshop and can be read here.
The American College of Sports Medicine and the American Heart Association recommend doing moderate-intensity cardiovascular exercise for 30 minutes a day, five days a week (for details of these guidelines, click here). However, elite athletes and tactical Warfighters need to train more to achieve higher levels of fitness—see the Navy Seal Fitness Guide and the Building the Soldier Athlete Manual for more information.