People often write or talk about the physiological differences between muscle fibers (fast versus slow twitch, oxidative capacity, etc.), but this information is generally not very helpful to the typical health and fitness enthusiast. It is certainly important to understand how muscles work, but most people don’t need to know all of physiology in depth. Instead, I think that understanding the basic functional differences between muscles provides more practical information than you would get from learning a lot about muscle physiology.

By looking at the functional differences between muscles, you can certainly go deep and examine how the various muscles work at each joint, but in the end, muscles are generally divided into two different functional categories: major motors and stabilizers. Prime movers are the muscles that actively create movement, while stabilizers provide balance and support for your body.

The prime movers are usually the largest muscles in your body and include muscle groups such as the quadriceps and hamstrings (upper thigh), pectorals (chest), lats (back), biceps and triceps (arms), etc. They connect to your bones (by tendons) and create movement around a joint. For example, your biceps connects your upper arm to your lower arm (forearm), crossing the elbow joint, and when your biceps contracts, you bring your forearm closer to your upper arm. Since the contraction of the biceps creates this movement, it is considered a prime mover.

Stabilizers, as the name implies, have more to do with stabilizing the body than creating movement. Stabilizers are smaller muscles and in many cases they are not even visible because they are too small or too deep below the surface muscles. These muscles help keep bones, joints, and muscles properly aligned both during movement and while standing.

Stabilizing muscles are also essential for maintaining good posture throughout your life. For example, the stabilizing muscles in your middle and upper back work to keep your shoulders back and in line with the rest of your body. If those muscles become too weak or the chest and front shoulder muscles proportionally become too strong or tense, your shoulders will begin to bend forward. If the stabilizing muscles are not strengthened to the point where they can reverse this change, then the rounding of the shoulders will progress and your posture will worsen over time, leading to additional problems.

Major motors and stabilizers play a valuable role in your body and any complete training program will include exercises or workouts to improve both types of muscles. It’s also important to note that since the major movers and stabilizers have different muscle functions and demands, they need to be trained differently. Unfortunately, many people try to train the stabilizers as if they were the prime movers and possibly an increasing number of people do not realize that the stabilizers need to be trained at all.

This is really not surprising, because most people in the fitness industry and the media still focus on using exercise to improve the appearance of their body and rarely spend time explaining how training can improve fitness. how your body works. It is a common assumption that training will always improve the way your body functions, but this is only partially true. A well-balanced program will improve the functioning of your body, but many programs are unbalanced or ignore important aspects that actually lead to physical dysfunction.

Improving stabilizer muscles is an example of something that is often left out of the average training program. Since stabilizers are so small, training them usually doesn’t cause any dramatic changes to your body’s appearance, so they don’t get a lot of attention and are often completely ignored. It is very tempting to train only the main engines, because they are responsible for the greatest calorie burn and physical change. While most of your training time can be spent on the prime movers, at least some stabilization training should also be included.

When resistance training (weight lifting, use of exercise bands, etc.), the main engines are generally trained by performing sets of exercises where each set typically contains between 3 and 15 repetitions, depending on your training goals. In general, lower reps and higher weight result in more strength gains, while higher reps and lower weight result in greater local muscular endurance. However, in both cases, the muscles are trained for a certain number of repetitions, usually until they become fatigued, and then there is a period of rest so that they can recover for the next set.

This type of training is effective, because the prime movers generally only work for shorter periods (with the exception of long endurance events), but the stabilizers often have to contract for hours every day. The difference is that the stabilizer muscles are designed to produce small, sustained contractions for long-term stabilization as opposed to short, strong contractions of the main motors. As a result, it is not necessary to train the stabilizer muscles to produce a greater amount of force over a short period of time.

The good news is that you can actually train your stabilizer and primary motor muscles at the same time, depending on the exercises you use. For example, the use of machines to work the leg muscles (leg press, leg extension, etc.) provides little benefit to leg stabilizers, but exercises performed while standing in a split position (one leg up forward and one leg back), on one leg, or on balance devices (Bosu, inflated discs, etc.) will challenge the stabilizer muscles along with the main motors.

One thing to keep in mind is that when you do exercises that challenge your stabilizers, your main engines won’t be challenged as much, because you won’t be able to use as much weight or perform as many reps as when you’re not using your stabilizers. This is because the energy that would be used to contract the main engines is spent on stabilizing and controlling movement. Also, your stabilizers may give way before your main engines, if the stabilization demand of the exercise is high enough.

However, for most people, the benefits of including stabilization training far outweigh the negatives of having slightly less major motor improvement. Unfortunately, there are not many incentives for people to include stabilization exercises, because they often do not realize the importance of stabilizer muscles, at least not until they begin to experience problems associated with malfunctioning stabilizers. In addition, these problems generally do not begin to occur until the middle or late stages of life and are often considered normal parts of aging, rather than preventable or reversible muscle and joint problems.

For example, let’s go back to my previous example of a person who has rounded shoulders. It is common for older people to have rounded forward shoulders along with excessive curvature in the upper back and spine. In most cases, this is not a normal part of aging and is actually caused by a combination of poor stabilizing muscle function, lack of flexibility, general lack of use of muscles, and the postural changes that result from these problems. .

When people strive to stay active, maintain flexibility, and practice good posture throughout their lives, rounding of the shoulders and other postural changes can generally be avoided. Fortunately, if you haven’t done everything you should have done when you were younger, there is still hope. A comprehensive training program, including stabilization training that targets problem areas, can go a long way toward reversing and preventing many of the muscle, bone, and joint problems typically associated with aging.