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HPRC Fitness Arena: Physical Fitness
Interval training alternates high-intensity movements such as running or cycling sprints with a recovery phase that consists of rest or low-intensity movement such as walking or slow cycling. Interval training improves your cardiovascular fitness, ability to burn fat, and ability to tolerate lactic acid build-up while lowering your risk for cardiovascular disease. Overall, adaptations from interval training can lead to improvements in strength, speed, and endurance while improving your body composition. Interval training is a .
A basic interval training session could include sprinting on the straightaways (100m) of a standard track and walking the curved portion (100m). Or alternate 30-second bouts of high-intensity exercise with recovery bouts. Initially, start with rest periods longer than the work periods, and work up to equal time periods as your fitness improves. If you are out of shape, have health problems, high blood pressure, or joint problems, check with your physician before starting a high-intensity training program. Read this article on the Mayo Clinic website if you would like to know more.
Swimming is a wonderful way to improve overall fitness while minimizing your risk of injury. It’s easy on your joints and improves your cardiovascular fitness. Although training in a pool may not simulate your specific duties, cross-training reduces the risk of injury from other repetitive exercise such as running. Effective pool training sessions should vary in intensity and emphasis. To avoid shoulder joint and upper back issues, warm up by swimming for five to ten minutes at a pace slower than your usual training pace, and include kicking and pulling drills. To improve both strength and endurance in the water, try interval training. Shorter rest intervals will improve endurance, while longer ones will stress your anaerobic system and improve your strength and power. Alternating between aerobic (longer and slower) and anaerobic (shorter and more intense) workouts will optimize your overall performance for both combat swimming operations and cardiovascular fitness in general.
For more detailed information about pool interval training and examples of training regimens check out Chapter 4: Swimming for Fitness in The US Navy SEAL Guide to Fitness and Nutrition.
A key concern for Warfighters and athletes alike is getting injured. Continuing to train through a minor injury can turn it into a major one. Even with minor injuries, it’s important to decrease inflammation and increase the range of motion at the affected joint. Two approaches to take are RICE and ISE. Start with RICE—rest, ice, compression, and elevation—to decrease inflammation. Once inflammation is minimized, ISE—ice, stretching, and exercise—helps to increase the range of motion. Using these techniques may reduce inflammation, stiffness, weakness, and/or loss of normal function. Once pain and swelling are reduced, the next step is reconditioning. Exercises that target the area of injury should promote flexibility, endurance, speed, strength, and power while progressing gradually. The main goal of reconditioning is to efficiently decrease pain and increase range of motion. Always check with your physician to rule out more serious injury before proceeding.
Chapter 12 of The US Navy Seal Guide to Fitness and Nutrition provides more detail.
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.