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HPRC Fitness Arena: Physical Fitness
Your body is a segmented, or jointed, system designed for potentially powerful and efficient movement. Coordinated and efficient movements require a give and take between mobility and stability of the involved joints, as well as the surrounding muscles, tendons, and ligaments. These components, together with muscular fitness, are necessary to achieve functional movement, which is integral in performance and sport related skills.
According to the American Council on Exercise (ACE), joint mobility—also known as range of motion (ROM)—is the degree to which a joint is able to move before it is restricted by surrounding ligaments, muscles, and tendons. Joint stability is the ability to control or restrict joint movement through the coupled actions of surrounding tissues. Preventing injuries requires, among other things, both mobility and stability of your musculoskeletal system. Deficiencies in one or the other, due to improper or imbalanced training, may lead to injuries during movement patterns, such as walking, running, and repetitive lifting.
One example of an elite training program is the Army Ranger RAW functional fitness program. It is unique in that it focuses on whole-body mobility and stability. Exercises are typically performed using your own body weight against fixed surfaces (i.e. the floor or wall), instead of using free weights or machine weights.
For joint stability and balance, the National Academy of Sports Medicine (NASM) recommends performing one to three sets of 12-20 repetitions at a slow, controlled pace. According to American College of Sports Medicine (ACSM), there is not enough research to make definitive recommendations on the frequency and duration for this type of training. However some research has shown improvements using training frequencies of 2-3 days per week, with sessions lasting ≥20-30 minutes, for a total of ≥60 minutes per week.
The amount of joint mobility is partially determined by the flexibility of the surrounding muscles, tendons, and ligaments. For example, decreased shoulder flexibility might impact your ability to complete a full pushup. Refer to these FITT guidelines for flexibility training.
Frequency: According to ACSM, short-term improvements in flexibility may be seen after each bout of stretching. More long-term changes, however, are seen after three to four weeks of regular stretching. Flexibility exercises should be performed at least two to three days per week, but daily exercise will improve range of motion.
Intensity: ACSM also recommends that flexibility exercises should involve major muscle groups (neck shoulders, upper and lower body), stretching to the point of slight discomfort within the range of motion, but no further. You should feel slight tension in the muscle, but it should not be painful.
Type: There are several different types of stretches:
• Static stretching slowly elongates a muscle by holding the position for a period of time.
• Dynamic stretching is usually sport specific. It requires a joint to be stretched through its full range of motion, to lengthen and increase the muscles temperature.
• Ballistic stretching is a type of dynamic stretch where the muscle is forcefully elongated through a bouncing motion. There’s no evidence that ballistic stretching results in injury, but there is still question and ongoing research as to whether this technique affects muscular performance.
• Proprioceptive Neuromuscular Facilitation or PNF stretching may produce greater gains in ROM, however, it may be less practical since an experienced partner is needed to perform this type of exercise.
Time: Your stretching routine should take about ten minutes or so to complete. Static stretches should be held for 15-20 seconds, while PNF stretches should involve a six-second contraction followed by a 10- to 30-second assisted stretch.
Use caution when working on mobility and stability exercises. Done properly, these exercises should not cause pain in the joint or muscle. Never push through your threshold, have patience, and treat your joints with care.
The 3rd annual Warrior Games took place at the beginning of May in Colorado Springs, Colorado. The United States Olympic Committee developed this “friendly” competition among the Navy, Air Force, Army, Marine Corps, Coast Guard, and Special Operations service men and women to promote sports programs for wounded, ill, and injured active and retired service members. If you think that these games are strictly to boost morale among wounded warriors, or to inspire the audience as they witness the amazing spirit among these military men and women, the highlights from this year’s event may change your opinion. These athletes train for months just to qualify for the Warrior Games, and many aspire to compete in the Paralympics. They devote hours every day to training for the games. Many of the competitors train together at Warrior Transition Units or other military facilities, and U.S. Olympic trainers and coaches are often on hand. You think you have what it takes to compete with the big dogs and win gold? Watch this video and decide!
Armed Forces Day was created in 1949 to honor Americans serving in the military. In 1962 President Kennedy established it as an official holiday on the third Saturday in May. Why should Armed Forces Day get attention on a DoD human performance optimization website? As director of HPRC, I think this holiday has the potential not just to honor the Armed Forces but for the Armed Forces to do what it has done many times in the past: respond to a crisis for the United States. The Armed Forces go to war to support a political strategy, and no national strategy at the present time is more critical than the war on obesity and tobacco. DoD has chosen these as part of the National Prevention Strategy. So how do we fight this war? We the military can start by setting the example for the rest of the country by bringing into our homes the practices of physical fitness and good nutrition as well as a smoke-free environment. We can make fitness and nutrition a priority for our spouses and children. We can make fitness and nutrition family activities that can promote good health, form stronger families, and make family members happier, closer together, and more productive. The military family can be the model for the civilian community to copy—a family working together toward a common goal of health and fitness. The payoff is tremendous in the present and the future. The military can be the beginning of a movement across the country to fight and win the war on obesity and tobacco use. The HPRC website has lots of helpful information in this war on obesity and tobacco. Check out the site (www.hprconline.org) and look under Physical Fitness, Nutrition, tobacco (under Mind Tactics Performance Degraders), and Family & Relationships. There is much that can be done. Join the war on obesity and tobacco. Set an example in your community for healthy living. Oorah! Hooah!
Working out by yourself is fine if you’re self-motivated, but getting a buddy to tag along can provide the motivation needed to really ramp up your workout. Let’s face it—a bit of friendly competition can help you push harder than if you were alone. In fact, research has consistently shown that performance is substantially improved when you exercise with someone (even a virtual partner)—unless the workout is complex or involves tasks that require coordination, when the performance can degrade (i.e., "choking under pressure"). So, for best results, practice your difficult routines with a trainer, and then engage in healthy competition to optimize your performance. Keep in mind that not just any friend will do. It’s best to get a buddy whose skill level is similar to your own.
If you have ever bought a pair of toning shoes, you probably noticed you haven’t developed a Kardashian-curved derrière or a Brook Burke body just from walking around in them. You’re not alone. Recent developments have brought toning shoes back into the spotlight for the media and scientific communities. An independent study by the American Council on Exercise found that these kinds of toning shoes do not increase muscle activation or caloric expenditure compared to regular athletic shoes. However, a positive outcome may be that these shoes have motivated people to get out and walk, a physical activity that has many health benefits—without special shoes! Caveat emptor!
In training, in the field, and even when you’re not thinking about it—such as moving ammunition boxes into a transport—your muscular strength and endurance are essential components of your overall fitness. But training to improve muscular strength is not the same as training for muscular endurance. Muscular strength is the amount of force that a muscle can produce with a single maximum effort. Muscular endurance is the ability to sustain a muscle contraction over a period of time, or to repeatedly contract a muscle over a period of time.
When applying the FITT principle to your muscular fitness routine, here are some guidelines to follow:
Frequency. According to the most recent guidelines set forth by The American College of Sports Medicine and in agreement with other military fitness programs, resistance training for muscular fitness—both strength and endurance—by the “whole-body” training approach should be performed two to three days per week with at least 48-72 hours of rest between training sessions. The “split-body” approach involves focusing on one set of muscle groups one day and a different set on another day. This allows for consecutive days of resistance training in a cyclical routine. For example, you might exercise upper body muscles one day, followed by lower body muscles the next, and core/back muscles the third day of the rotation. Cycles in the split body approach will vary depending on how many muscle groups are exercised per day.
Intensity. With consistent training of two to four sets of reps per muscle group, most people see an increase in the size and strength of their muscles. However, even one set can result in improvements, especially in novice exercisers. When training for muscular strength, the weight you use should be about 60-80% of your one-repetition maximum (1RM). If you’re new to weightlifting or have not lifted weights for a while, start at 60%. (See our Healthy Tip on how to determine your 1RM.) For muscular strength, aim for eight to 12 reps per set, with a two- to three-minute rest between sets. If your objective is to improve your muscular endurance, the recommendation is 15-25 repetitions at no more than 50% of your 1RM, with a two- to three-minute rest between no more than two sets. A well-rounded muscular fitness program should include both strength and endurance training, but consider your specific goals when deciding on your approach.
Type. There’s a lot of different equipment you can use for resistance training, including machines with stacked weights, free weights, and resistance bands. Some exercises don’t require equipment, just your own body weight. For example, pushups and sit-ups, as assessed in the PRT, will help improve your muscular endurance. Individual exercises should focus on the major muscle groups such as the chest, shoulders, upper and lower back, abdomen, hips, thighs, and calves. Read more about the advantages and disadvantages of different types of training equipment, and about workouts that utilize your own body weight or minimal equipment.
Time. The duration of a resistance-training workout can vary considerably and is less important than maintaining proper form and technique. As for the tempo of each exercise, The American Council on Exercise (ACE) recommends lifting the weight for a count of two seconds, and lowering for a count of three to four.
Progression. According to ACE, once you are able to perform the maximum number of repetitions correctly and with relative ease, increase the amount of resistance by five to 10%. This applies to repetitions performed for both strength and endurance.
Minimize the risk of injuries by using proper form, exercising with a partner, and paying attention to signs of excessive fatigue and pain. And if you’re new to resistance training, consult a certified personal trainer on proper lifting techniques.
The next Op-Ed in this series will discuss mobility training for the PRT.
When you begin a resistance training program, how do you know how much weight you should be lifting? Most muscular fitness programs are designed around lifting a percentage of your maximum strength.
The first step in this process is to determine what your maximum strength is. A popular technique for assessing muscular strength is the one-repetition maximum test (1RM), or the maximum amount of weight you can press once but not twice. Alternatively, multiple repetition tests can be performed as a reliable estimate of maximum strength. One study found that a five- repetition test was the most accurate, but no more than 10 reps should be used to estimate strength. This instructional video will demonstrate the ACSM protocol for a 1RM test. This protocol can also be applied to a multiple-repetition test. For example, determine the maximum amount of weight you are able to lift five times, but not six times, for a five-rep max test. If you have doubts about whether this is the right test for you, be sure to consult your doctor.
The second step is to determine what percentage of your 1RM, in weight, you should use to improve your muscular strength and endurance. Typically, improvements in muscular strength are seen when using 60-80% of your 1RM. Increased muscular endurance is achieved using about 50% of your 1RM. Read more on muscular fitness and more details on how to train for each here. Once you have assessed your maximum strength, use this conversion chart from the National Academy of Sports Medicine (NASM) to determine percentages of your 1RM.
In a recent study investigating risk factors for discharge from Army Basic Combat Training (BCT), researchers concluded that increased risk for both men and women was associated with failure on the initial two-mile run test. The current Physical Fitness Tests (PFT) or Physical Readiness Test (PRT) use a one and a half to two-mile run test to assess cardiovascular, or aerobic, fitness.
When mapping out a fitness program, learn the components of the FITT principle and apply them for each type of training. FITT stands for “frequency,” or how often; “intensity,” or how hard; “type,” or the kind of activity; and “time,” or how long. Progression (see below) is also an important part of an exercise plan. Using the FITT Principle, here are some guidelines to help optimize your cardiovascular fitness.
Frequency. The U.S. Surgeon General and other U.S. government agencies recommend physical activity on three or more days a week.
Intensity. According to updated guidelines The American College of Sports Medicine (ACSM) recommends adults engage in moderate-intensity exercise (i.e., at 40-60% Heart Rate Reserve (HRR)) five days a week or vigorous-intensity exercise training (i.e., at ≥ 60% HRR) three or more days a week. They also recommend a combination of moderate- and vigorous-intensity exercise. You can use this calculator from Kirtland AFB to determine your HRR.
Type. ACSM defines aerobic activities as being continuous, rhythmic, and using large muscle groups, such as your lower and upper body muscles. Examples of these kinds of activities are running, biking, swimming, rowing, and jump roping.
Time. The Surgeon General, ACSM, and American Heart Association recommend expending at least 1,000 calories per week through exercise (i.e., in addition to calories burned through normal everyday activities). This can be achieved through moderate-intensity exercise, as described above, and should last about ≥ 30 minutes per day for a total of ≥ 150 minutes per week; or with vigorous-intensity exercise for ≥20 minutes per day for a total of ≥75 minutes per week. The maximum safe duration is unknown, but exercise lasting more than an hour and a half increases risk of overtraining and/or overuse injuries such as stress fractures.
Progression. During the initial phase of an exercise program, ACSM recommends increasing duration (minutes per session) gradually. Increasing 5-10 minutes every one or two weeks over the first four to six weeks of an exercise program is reasonable for healthy adults. After an exercise routine has been maintained for one month or longer, it is reasonable to gradually increase frequency, intensity, and/or time over the next four to eight months. As a general rule of thumb, though not scientifically backed, increasing your workloads or volume by 10% will also help you gradually progress your exercise program.
Due to the repetitive and rhythmic nature of aerobic exercise, overuse injuries can occur as a result of your training. Cross training—training with a variety of aerobic exercises—is recommended. Examples of this would be alternating running, swimming, and rowing exercise sessions.
Part two of this series (upcoming) will address the muscular strength component of PFT/PRT.
For whatever reason, sometimes we get off track with our fitness regimens—maybe it was an injury, a move, or just life that intervened. Getting back to a peak level of fitness after time away should be done gradually. Injuries such as tendonitis—which could become a long term issue—can occur as a result of doing too much, too fast. The American College of Sports Medicine (ACSM) recommends increasing duration (minutes of exercise) 5-10 minutes every one or two weeks over the first four to six weeks of an exercise program.
There are several risk factors for stress fracture development, but a 2011 article in Medicine and Science in Sports and Exercise found that maintaining adequate muscle strength and flexibility in the hips, legs, knees, ankles, and feet is of great importance, especially for women. Here are some exercises from the American Council on Exercise that can help you build strength and flexibility:
Before beginning any exercise program, however, make sure to consult with a medical professional, especially if you are more than 45 years old.