Preparation for the PFT/PRT Part 2: Developing muscular strength and endurance— published: 05-23-2012
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.