Follow Ten Principles of Muscle Training for Safe Muscle Building and Efficient Fat Burning

Ten Principles for Muscle Training
Human muscles possess extensibility, elasticity, and viscosity; their fundamental characteristics are contraction and relaxation. Muscle contraction and relaxation are both controlled by the central nervous system. Therefore, when conducting muscle strength training, the following ten principles should be observed.

(I) Selection of Muscles to Train
The human body has approximately 500 skeletal muscles. Therefore, training should be focused and prioritize the large muscle groups that play a dominant role in daily life skills (see Section 3 of this chapter). Strengthening these muscles can improve daily life skills, develop muscle mass, and improve physique.

(II) Frequency of Training Per Week
Some studies have compared the various indicators of people who train four times a week (Monday, Wednesday, Friday, and Sunday) and those who train twice a week; the latter performed worse than the former. Experiments conducted by scientists from the U.S. Air Force and NASA have demonstrated that the rate of muscle atrophy after exercise is astonishing! If a person does not exercise for three days, their muscle strength will lose one-third; muscles that have already been exercised must be exercised again within 48-72 hours to establish the necessary physical effects. That is to say, the beneficial effects of human metabolism can only be maintained for a maximum of 2-3 days; if this time limit is exceeded, function will be greatly reduced. Therefore, muscle training should be conducted at least 3-4 times per week.

(III) Scheduling of Each Exercise Session Studies by Soviet physiologists such as Schebina et al., measuring changes in leg strength during vertical jumps and arm strength during bench presses in weightlifters aged 18-28, have shown that muscle strength varies throughout the day, but the peak contraction strength occurs between 11:00-14:00 and 19:00-21:00. Upper limb strength changes by 10%, and lower limb strength changes by 30%. Human bodily functions vary greatly throughout the day. Muscle speed, strength, and endurance are at their peak between 8-12 AM and 2-5 PM, and at their lowest between 3-5 AM and 12-2 PM. Therefore, it's best to schedule exercise when muscles are at their relatively optimal state to avoid injury and achieve the best results. Primary, middle, and high school students can schedule exercise between 4-5 PM, when muscles are at their best, which helps improve muscle load capacity and simultaneously excites the motor center and inhibits the cognitive center, achieving active rest.

(IV) Load Selection An individual's strength depends primarily on the central nervous system's control over the muscles and the characteristics of the muscle structure itself. Different individuals have different numbers of muscle fibers and varying ratios of red muscle fibers (divided into fast-twitch and slow-twitch red muscle fibers) to white muscle fibers (fast-twitch white muscle fibers). Therefore, the load should be tailored to the individual and the time of day. Experiments and experience have shown that when performing strength training with light to moderate weights, the number of repetitions should be increased, generally around 12 repetitions, to effectively promote muscle growth, although strength gains will be slower. If the load is heavy, the number of repetitions should be reduced, generally to 3-5 repetitions. This type of training best improves the regulatory function of the nervous system, resulting in faster strength gains. In other words, using more than 50% of your maximum strength primarily trains fast-twitch muscle fibers, leading to increased muscle volume and strength; using 25% of your maximum strength primarily trains slow-twitch muscle fibers. A combination of heavy, medium, and light loads should be used in training to adjust the range of motion, speed, and rest intervals for better results.

How do you determine 50% or 25% of your maximum strength? Taking weightlifting as an example, if you can lift 100 kg, then lifting 50 kg and 25 kg represent 50% and 25% of your maximum strength, respectively.

(V) Exercise Rest and Rhythm: Experiments have shown that short rest intervals and a fast pace are more effective. After warming up, each exercise should be completed 10-12 times (3-5 times for heavy weights) within 60-80 seconds. Each repetition of each exercise should allow the muscles to fully extend and contract to their maximum extent, reaching a certain limit. Only in this way can muscle elasticity, volume, and strength be increased, achieving maximum benefit.

(VI) Exercise Speed: Muscle strength training should alternate between fast and slow movements, avoiding rapid repetition as much as possible. Rapid repetition generates momentum that greatly exceeds the muscle's load-bearing capacity, easily causing bone, muscle, or ligament damage.

(VII) Exercise Density: After a thorough warm-up, complete 8-10 exercises within 20-30 minutes. The rest time between sets and repetitions should be short, generally controlled within 40-60 seconds. The movement speed should be such that muscle contraction takes 2-3 seconds and relaxation takes 4-6 seconds, in order to achieve the dual purpose of developing muscles and improving cardiopulmonary function.

(VIII) Range of Motion: During each set and repetition, exert maximum effort to maximize the extension and contraction of the targeted muscle groups. Pause briefly at the maximum contraction to allow for full muscle extension in the next repetition, maximizing the benefit to the targeted muscle groups.

(IX) Muscle Load: From a sports physiology perspective, muscle tissue adapts slowly. Therefore, muscle load should be increased gradually. In a weekly cycle, the increase in load between cycles should not exceed 5% of the previous cycle; otherwise, injury is likely.

(X) Attention to Muscle Origin and Insertion Points and External Force: In every muscle strength training exercise, the origin and insertion points of the muscles should be close to or adjacent to each other. The applied external force should be opposite to the direction of the muscle pull. For example, to develop the triceps, in addition to push-ups, exercises such as behind-the-neck curls, bench presses, handstand push-ups, triceps extensions, martial arts punches, and shot put can all achieve the goal of developing the triceps. While the body posture and applied external force differ when performing these movements, they all bring the origin and insertion points of the triceps brachii closer together, and the external force is opposite to the direction of the triceps brachii's pull.

When performing stretching exercises to develop muscles, the origin and insertion points should be separated as far as possible, such as leg presses, kicks, splits, and "bridges." Aim for a large range of motion and apply appropriate force to help lengthen the relevant muscles and ligaments.