There Is Only One Kind of Strength

Mr Toigo, what role does strength play in people's everyday lives?
Our lives are dictated by gravity. It pulls us towards the centre of the earth even when we are sitting, and we always and everywhere have to fight against gravity. We need our muscles for this; without them we could not move. Strength is the foundation of every movement.

Which form of strength is the most important for people?
There is no ranking, because the term "strength" is based on physics. There is only one kind of force, and it is measured in newtons. Terms such as explosive strength, speed strength or strength endurance are therefore wrong, unlike gravitational force or centripetal force.

But there is a difference whether a muscle has to work endurance-wise on the bike for an hour or should lift as much weight as possible just once, right?
The difference in terms of strength lies in the relative level of force, how many times and at what frequency this force has to be applied over time, and how quickly the force is developed during the movements. Instead of "speed strength", one should therefore use "rate of force development" or impulse if you want to quantify speed. Notably, the force generated by muscles is a neuromuscular product. Neural components of strength include, for example, the frequency at which individual muscle fibres are activated, or intermuscular coordination, i.e. the timing of the activity of different muscles involved in the movement. Muscular components include, for example, the distribution of muscle fibre types and the cross-sectional thickness of the individual muscle fibres. So one cannot train "speed strength", but rather the neuromuscular factors for rapid force development. And if you want to sustain a submaximal performance for as long as possible, as in the cycling mentioned, then a high mitochondrial density in the muscle fibres is decisive.

Can you train a muscle in isolation with strength training, or is neural implementation always practised automatically too?
Both. Conventional strength training is a practical process in which a voluntary movement takes place. Already after 1-2 weeks of training you can move more resistance on the machines or with dumbbells. This effect is primarily due to neural mechanisms. Although the process of muscle cross-sectional growth is initiated with the first training session, provided you train correctly and your protein intake is right, the effects of training on the increase in muscle cross-section only become measurable after a few weeks. The neural effects, however, are movement-specific: in strength training on a leg press you primarily <learn> to extend both legs and hips simultaneously in the prescribed angular position, so little neural transfer from leg extension on the machine to the pedalling motion in cycling is to be expected. Conversely, some of the muscle fibres trained on the leg press are certainly also used when cycling. Therefore, unlike the neural training effects, the muscular training effects are more transferable.

Endurance athletes are not distinguished by huge muscle mountains compared with speed-strength athletes. How are performance and strength related in endurance sport?
As a formula there is a clear definition: power in watts = force x speed. Or power = work divided by time. What matters most for endurance athletes is the greatest possible output that can be sustained for as long as possible in metabolic equilibrium, as well as the work capacity above this critical power, i.e. in the 'red' zone. The external power when cycling depends on the force on the pedals as well as on the cadence. How long an athlete can sustain this submaximal output is determined by various cardiovascular, muscular and psychobiological factors, such as motivation.

What does this mean for endurance athletes in terms of strength training? Should they do strength training on machines at all?
Strength training also makes sense for endurance athletes, because it can increase the ability to ride in the <red> zone. Strength training can also be used deliberately to fatigue the muscle before an endurance training session. In this way, training volume can be saved in favour of recovery time. It is important that strength training is sensibly integrated into the training plan and that it is complemented by sport-specific implementation.

Are there no universally valid rules?
No. The training and nutrition programme as a whole must be evaluated by scientists, and athletes must be scientifically tested, before recommendations can be made. In practice, however, training recommendations or prescriptions are often based primarily on assumptions or personal experience that have no scientific basis. This is a problem, because with assumptions and personal experience it is very difficult to establish a causal link between cause and effect. It is therefore worthwhile to keep questioning common training practice, even when people say "we have always done it this way" or "the x-times world champion XY trained like this too". Many triathletes or cyclists, for example, train single-leg cycling because they want to train their pulling phase and their smooth pedal stroke. But do they really achieve this with it? How do they measure whether this goal has been reached? By "feel"? Feelings can deceive, as a look at the local divorce rate shows. In practice, cyclists don't have to ride one-legged either; they always ride with both legs. So if they ride one-legged, they are practising a movement they don't actually need.

Back to building up a muscle's strength. What does sensible strength training look like for recreational athletes?
The term "strength training" is imprecise and therefore leaves a lot of room for interpretation. Some endurance athletes understand it as riding uphill in high gears, while bodybuilders primarily understand it as lifting weights to build muscle mass. Depending on the sport, the goal therefore lies more on the NEUROmuscular or rather on the neuroMUSCULAR aspect of strength. If the goal is, for example, to increase muscle mass, the so-called muscle hypertrophy, then the muscle should be driven to complete voluntary exhaustion in a short time, as a guideline 1-2 minutes. This means the training resistance must be chosen so that, with anatomically correct, slow and controlled execution of the movement, it can no longer be moved at some point between these 1-2 minutes. Furthermore, training should be progressive. If a time under tension of 1 minute was achieved in the first session, the next session should try to exceed this time under tension. And once 1.5 minutes of time under tension has been reached, the training resistance can be increased by the next smallest increment, which reduces the time under tension again to around 1 minute. This process is repeated. One to two intense training sessions per week for the same muscle make sense.

How many repetitions are roughly needed?
For a given time under tension, the number of repetitions depends on the speed of movement. One repetition consists of a concentric, isometric and eccentric phase. In all three phases the muscle should produce force, and a loss of force should be avoided as far as possible. In the concentric phase the muscle shortens, in the isometric phase the overall length of the muscle remains unchanged, while in the eccentric phase the muscle length increases again and the muscle should be actively stretched. So if you use 4 seconds each for the concentric and eccentric phases and 2 seconds for the isometric phase, that gives 10 seconds per repetition. With a time under tension of 1.5 minutes, that results in nine repetitions. It is advisable to focus on exhausting the muscle completely in one set and to perform different exercises for the same muscle group, rather than repeating the same exercise several times in a row. In my observation in practice, few people perform an exercise set correctly. This has to do with the associated higher pain sensation, as well as with personal preconceived, scientifically unproven views, for example that more sets of the same exercise would bring more muscle growth.
l0 seconds of exercise execution sound slow and exhausting. Why does it have to be so slow?
In training for muscle cross-sectional growth, the movement should be slow and smooth, so that the training resistance gains no momentum. If it gains a lot of momentum through "explosive" application of force, it moves on its own. The trainee must then apply less force, which in turn leads to derecruitment of motor units in the meantime. In addition, the risk of injury increases with increasing speed of movement. "The" best speed of movement does not exist. As a guideline, however, the rhythm mentioned, around 4 seconds concentric, 2 seconds isometric and 4 seconds eccentric, is suitable. A special case with regard to speed of movement is hypertrophy training in which exclusively or predominantly eccentric muscle contractions, so-called "negative training", are performed. Here, at the start of the exercise the training resistance can be braked very slowly. At the end of the exercise, at the point of muscle exhaustion, the movement can hardly be controlled any more due to muscle fatigue, and the resistance returns almost unbraked to the starting position. Consequently, the time under tension for a single eccentric contraction can vary greatly: at the beginning of the exercise it is very long, around 10 seconds, but at the end only very short.

How much strength training per week makes sense?
That depends on the individual situation. In general, one can say that a hard load on the same muscle once or twice a week is enough.

May or should you combine strength and endurance training?
If one and the same muscle undergoes strength and endurance training at the same time, i.e. within minutes or a few hours of each other, the activation of the muscle growth process is slowed compared with strength training alone. The neural component of strength, however, is trained similarly well. Endurance athletes who want more "strength" but not necessarily thicker muscles can therefore benefit from such a combined training. For people who want to maximise their thigh muscle mass, such an immediate combination is rather unfavourable. In this case, endurance training for the muscle just trained for hypertrophy should be moved to another day.

How much muscle training is needed to gain strength?
Three months of biceps training results, in previously untrained men, on average in a 20% increase in muscle cross-section. The effect is, however, very individual. Some gain 0% in the same period, others up to 50%.

Why? Because a lot is down to genes and doesn't depend on training at all?
A lot is indeed down to genes. In endurance sport the influence of hereditary factors is estimated at 50%. For adaptability in terms of muscle hypertrophy and strength, the estimated share of the genetic component is even around 70%. For people who respond with a very strong adaptation to training, one cannot say how much of the training success is actually due to the training method. They may look like that "despite" the training they do. That is why, in principle, there is little point in trying to copy the training programmes of such "high responders", with the wishful thinking that the result would always be the same.

How much does strength depend on age?
From 40-50 years onwards, muscle mass in untrained people decreases on average. However, this can be counteracted with hypertrophy training and adapted protein intake. When men and women of around 65 start progressive strength training, they can, within four months, bring the average muscle fibre cross-sectional size of type 2 muscle fibres up to the level of untrained people of around 30.

How heavy are the muscles compared with the rest of the body?
In a healthy young man, pure muscle mass is around 40-60% of body mass. The lean mass index, defined as lean mass in kilograms divided by body height in metres squared, is around 19 kg/m2 in a physically active young man, and up to 29 kg/m2 in an elite bodybuilder.

How important is nutrition for building muscle?
For a muscle to gain mass, the metabolic basis must be in place: the net protein balance must be positive. This means that the muscle building rate must be greater than the muscle breakdown rate. Only then is protein stored in the muscle and the muscle grows.

And how is this muscle building rate regulated?
On the one hand through hypertrophy training, on the other through essential amino acids, whereby the two stimuli act synergistically. This means that through a time- and dose-optimised intake of essential amino acids, the effect of training can be potentiated.

Amino acids are parts of proteins. So do you recommend taking protein after strength training?
Yes, namely just under 20 grams of protein immediately and again about an hour later. The rate of protein synthesis rises after training. It therefore makes sense to additionally stimulate the increase with amino acids. Important: in adults, no muscle growth occurs without adequate training. It therefore brings absolutely nothing to gobble down masses of protein. At most, you gain fat from it. Even after training, excessive protein intake brings no further effect on muscle protein synthesis. On the contrary, amino acid oxidation can be stimulated. The muscle cannot use 100 grams at once. More is simply not always better. This applies to training as well as to protein intake. For protein intake, the timing, the amount of protein per intake and the number of intakes per day are particularly important.

Which foods are an easy way to get valuable protein?
Milk, for example. Or meat, low-fat quark, peas and so on. Or sensibly composed commercial products. The choice of protein source depends on practicality, personal preferences and physiological considerations. With meat, it takes comparatively long for the amino acid concentration in the blood to reach its peak, whereas the amino acids in a protein shake are available to the muscle fastest.

Sources: Interview: Andreas Gonseth, fit4life