How do I build strength in the gym

Which strength training method causes the maximum increase in performance?

Strength training: The traditional rules provide for 2 or 3 training sets up to exhaustion, as this should guarantee the athlete a rapid increase in strength. However, researchers have now found that less could be more here. John Sampson explains why.

Strength training? Muscle strength? Yes, but for what?

In many sports you need muscle strength in order to perform well. It is required for many performance-specific characteristics, including speed and quick strength. Muscle strength is usually developed by completing a structured strength training program over a longer period of time. However, although numerous studies have been carried out in this area, the mechanisms that lead to adjustments of the maximum force are still not fully understood.

The skeletal musculature is an extremely sensitive tissue with a high level of adaptability. Any overloading of the muscles therefore leads to a certain adjustment (i.e. a gain in strength). Even suboptimal resistance training can still lead to positive adjustments. In the long run, however, poor strength training programs do not lead to optimal strength gain and sometimes even to poorer performance and an increased risk of injury.

There are different principles and guidelines in strength training programs. According to legend, the Greek athlete Milon von Kroton put a calf over his shoulders every day and carried it around with him until it was fully grown. And as the animal got bigger and stronger, it also gained in physical strength. This story clearly illustrates how important it is to gradually increase the external load!

The stress of strength training

The mechanical stress that acts on the muscles through external stress is probably the most important aspect of strength training. Scientific research has shown time and time again that moderate to heavy loads are required to increase muscle size, muscle activity and muscle strength. In the literature as well as in the current guidelines of the American College of Sports Medicine (ACSM) you can read that relatively high loads are required for optimal strength gain, the maximum with 1 repetition (1 RM) or more than 80% of 1RM should lie.

Strength training programs can be varied not only through the externally applied load, but also through the speed of the contractions and the extent of the fatigue generated in each case. If you change the strength training program in just one of these factors, there will be a marked reaction from the skeletal muscles.

If you change the training in 2 or more of these factors, you achieve a combined effect that leads to complex physiological interactions, as a result of which the gain in strength through the training is either weakened or increased. Unfortunately, there is still insufficient evidence to fully understand the complex interplay of load, speed of movement, and volume-induced muscle fatigue (e.g., number of sets and repetitions performed).

The brain and muscle contractions

The muscle contractions are ultimately controlled and regulated by the brain. The muscles are controlled via motor units. When a motor unit is activated, the muscle fibers it controls contract.

This is often referred to as the “neural control of force” and is essentially dependent on the number of active motor units and the speed with which they act. The activity level of motor units is directly proportional to the strength required for a particular task.

The optimal strength training program

It is known that a structured strength training program creates larger muscles (hypertrophy), and that larger muscles have more strength potential. However, when you start weight training you will find that while your muscles initially gain strength, they do not increase in size. If strength gains are achieved without increasing muscle size, this generally has to do with increased "muscle activation", i. H. a better recruitment of motor units that "fire up" the muscle fibers.

In order to achieve the greatest gain in strength, the muscle fibers must be maximally activated during strength training. As you do a set of strength exercises, you will surely find that the difficulty increases as you do a lot of repetitions. The reason for this is that the motor units tire and more of them have to be recruited in order to be able to maintain the desired strength output. As a result, as the muscle tries to exert the force required to cope with the load, the level of muscle activity increases.

Training with "repetitions to failure"

This also explains why “rep to failure” training is an important part of designing a strength training program. Delorme (1945) (2) and later Delorme and Watkins (1948) (3) wrote a series of studies on the effect of progressive strength training in rehabilitation training about a training control beyond the "1 repetition maximum (1 RM)" . 10 repetitions were recommended with a load that had to be so great that it led to "failure" (e.g. muscle fatigue) on the 10th repetition.

This exercise technique is also called the "10 repetition maximum" (10 RM). Around 60 years later, maximum repetition exercise is still the dominant strength training model in the scientific literature and in fitness studios. “Training to failure” is closely related to maximum strength adjustment, and so most of the strength training programs recommended by sports and fitness trainers lead to excessive muscle fatigue.

Operational vs. multi-sentence training

However, scientific research into the necessity of excessive, intentionally induced muscle fatigue is unconvincing. Most strength trainers work with multiple sets for maximum strength gains. When comparing training programs with several sets or a single set, however, the evidence is very contradictory. It has not yet been proven whether a high training load and the resulting fatigue are actually the basic prerequisites for force adjustments.

The amount of muscle fatigue cannot be influenced just by increasing the number of sets in a strength training session. Studies have also looked at the effect of taking short breaks between repetitions in a strength training program. Here, too, 2 of the studies came to different results. (4,5)

The amount of muscle fatigue

In both studies, 2 strength training programs were examined in which a relatively large external resistance was used:

- In one program, the fatigue was generated by the participants having to do the repetitions without a break until they failed (muscle fatigue).

- In the other training program, participants had to do the same number of repetitions, but had a 30-second rest period between repetitions so that they could recover a little.

Then the strength gain after the “very tiring” training was compared with that of the training when the fatigue was less severe. While one study came to the conclusion that the group with more fatigue achieved greater strength gains, the other study found no differences between the groups. This presents us with a problem. Because while one study is clearly in favor of greater muscle fatigue, the other does not consider it necessary.

Strength training and training efficiency

When people move, they do mechanical work and consume energy. Therefore, if the same work can be done with less energy consumption, this movement will be more efficient. For strength training to have the desired effect, certain adjustments must be made (i.e. an increase in strength and muscle size). A training program that requires less energy but leads to the same adjustments as another program is considered more efficient.

Gain strength through repetitions to failure

The need for "repetition to failure" was also questioned. A new study compared the strength gains that one training group achieved on exercise sets with "repetitions to failure" with those of a second group that performed the same number of repetitions in total but completed more sets (i.e. no repetitions were made by (6) According to this study, similarly large gains in strength were achieved in both groups, even though the training stimulus was less tiring in the group with the greater number of sets.

Various scientific studies therefore suggest that similar strength gains can also be achieved if less muscle fatigue is generated. However, it must be emphasized that ultimately all groups achieved the same relative training performance and therefore the training efficiency was the same in both groups.

Some researchers recommend doing exercise programs with just a single set. In their opinion, this increases training efficiency without affecting strength gains. However, this view is highly controversial. However, there could be an important correlation between repetition speed and the amount of fatigue generated in each case. Repetitions can be done quickly or slowly, and both methods have been used in scientific studies on the subject.

Consciously "slow" strength training

In a new study on deliberately “slow training,” the mechanical effects of such an approach were discussed. (7) In summary, the researchers stated that slow repetitions take longer to cause muscle contraction in the range of motion (so that the muscle is practically live longer).

However, they emphasize that the strain must be reduced when the muscle is under tension for longer. In view of the legal relationship between external exertion and muscle adaptation, this finding seems to be in direct contradiction to the generally accepted view that the adjustments in strength training are proportional to the exertion.

Increasing the duration of a muscle contraction is not the only way to increase the total time a muscle is under tension. The same effects can be achieved by increasing the number of repetitions. Both methods cause greater muscle fatigue and ultimately lead to muscle failure. But none of these methods can really improve strength training efficiency.

Explosive muscle contractions

Repetitions can not only be done deliberately slowly, but also as quickly as possible. Such training is also known as "explosive" or "ballistic" training. The muscles must therefore be activated to the maximum so that the muscles are stimulated and maximum strength gains are achieved during strength training. Explosive muscle contractions cause force to be generated very quickly, the motor units are fired faster and the recruitment threshold for the motor units is lowered.

Explosive muscle contractions can therefore lead to better muscle activation. But in order to be able to carry out an explosive movement, the external load must be reduced, while on the other hand a relatively large external force is necessary in order to achieve maximum force adjustments. Proponents of deliberately slow training claim that it makes explosive training less efficient.

But one can also try to do an explosive contraction with a large external load. However, trying to make quick movements takes a lot of force. This has to do with indolence. If you are trying to accelerate a mass very quickly, you will have to generate significantly more force to overcome the inertia than if you were to move slowly with less acceleration.

Muscle contractions during exertion

If you are doing explosive contractions at relatively large loads, you will likely increase your fast force-oriented performance characteristics as well, while achieving the same force adjustments when you perform the contractions at the same load but at slower speeds. (9)

The combination of great external stress and maximum contraction speed is also favored in strength training programs with 1 exercise set. Australian scientists studied e.g. B. the effect of fast or slow strength training with 1 set or 3 sets on the maximum strength adjustment. In this 6-week training program, every set was performed to failure. (10)

The study found that strength gains from one set with high load and high speed were similar to three sets at slower speed. In addition, it has not been shown that 3 sets of faster speed have any other benefits. A “heavy weight explosive contraction” could be an important performance-related variable in this area.

Explosive contractions and limb movement

Trying to perform an explosive contraction is considered an effective method of promoting rapid muscle adaptation. This also applies if the contraction is performed against isometric resistance and without moving the limbs. So it seems that the intention to perform rapid contractions is more important than the actual movement of the limbs. (8)

New investigations

Scientists at our research laboratory at the University of Wollongong, Australia share the view that an “explosive contraction under heavy load” increases training efficiency. They influenced the amount of work done (and thus the amount of muscle fatigue generated) and the speed with which the repetitions were performed.

Fig. 1: The strength gains for the participants in the conventionally training group (group 1) and the fast and explosive training group (group 2) were approximately the same. © trainingsworld

One training group completed 4 sets of strength exercises with relatively high external loads, so that the muscles failed after about 6 repetitions. A second group should also do 4 training sets with the same relatively large external load.

However, this group was left to work less, i. H. do only 4 reps. Also, this group should do the repetitions as quickly (i.e. explosively) as possible. The first group (with muscle failure), on the other hand, performed the repetitions every 4 seconds, had a muscle shortening phase of 2 seconds (usually when lifting weights) and a muscle lengthening phase of 2 seconds (usually when lowering weights).

Fig. 2: The different training volumes of both groups. Although the subjects who trained quickly and explosively (group 2) performed around 30% fewer repetitions than the subjects from group 1, they nevertheless achieved similarly large gains in strength. © trainingsworld

After 12 weeks of strength training, both groups had achieved similarly large gains in strength. These results are significant. Because although the 2nd (explosive) group did a total of 30% less work than the 1st group, they still achieved equally large gains in strength, without training to the point of muscle failure (see Fig. 1 and 2). Apart from an approximately equal gain in strength, both groups also had a similarly large gain in muscle size and muscle activity. This shows that the more strenuous training in group 1 had no advantages in terms of force adaptation.


These studies suggest that the efficiency of a strength training program can be increased by choosing a relatively high load and doing fewer repetitions, but using explosive muscle contractions. This has the following positive effects for athletes:

- The increased efficiency of strength training reduces the time in which the athlete has to use strength to achieve a certain increase in strength. This frees up time for other relevant aspects of the training.

- If the athlete does not have to act to failure (which can be very exhausting), he will recover faster and have more energy for the next training session.

- Most competitions and events require explosive movements. When explosive strength training is as effective as traditional training in building strength, the athlete can benefit from both the unique nature of explosive training and the strength gains.

However, I would like to give the following warning: During explosive strength training with high loads, there is an increased risk of injury to muscles and / or joints due to the forces generated by the rapid acceleration and movement of the weights at high speed. On the other hand, we believe that the risk of injury is actually lower with the strength training model used here. Because despite the explosive contractions examined, the fatigue of the muscles in our experiment is less because fewer repetitions are made.

Practical tips

- Athletes and coaches should be aware that most traditional strength training programs, while increasing strength, are not necessarily in the most efficient way.

- Athletes whose sports include explosive movements should give explosive strength training a try; because that is not only very time and energy efficient, but also corresponds to the recruitment pattern of the muscles.


1 rep maximum (1 RM) - the maximum weight that can be lifted once over the entire sequence of movements without outside help

Motor units - carry the information from the central nervous system to the muscle fibers. A motor unit comprises all muscle fibers that are stimulated by a nerve cell and the nerve cell itself.

John Sampson is a lecturer at the University of Wollongong in Australia. He is doing his doctorate on the effects of strength training and the associated skeletal muscle adaptations.


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