5. Improving performance

Discussing this unit, we will base our ideas on the line of thinking and thematic sequence of the relevant chapters of the book entitled Physiology of Physical Training by Zsolt Radák (Radák 2016).

During training, we develop the performance-determining characteristics which are the most important in the given sport. On the basis of this, we can distinguish several areas of a physical nature, from the development of which we can expect an improvement in sports results. Of course, these are not truly separate from each other, because each is a component of sports movement; however, the choice of the focus of the training can develop one or the other with more efficiency. The areas in question are:

  • strength

  • endurance

  • speed

  • articular mobility

  • coordination.

Besides these, naturally, the development of both sport-specific and general mental characteristics (e.g. psychological endurance) is also of paramount importance, but this discussion belongs to the Sports Psychology courses.

5.1. Developing strength

Strength plays an outstandingly important role in most sports, as it is a characteristic which greatly influences muscle work. The magnitude of the exerted force is determined by several factors, which will be reviewed in the following sections.

5.1.1. Protein quantity in the muscle: the quantity of actin and myosin

One of the factors previously mentioned is the number of actomyosin units performing contraction, which is proportionate to the cross section of the muscle. From this it follows that with the growth of the cross section of the muscle, an enhancement in the strength of the muscle can be achieved. In common thinking, this constitutes the most fundamental – and many times the only – causative factor behind great muscle strength: on the principle of “bigger muscle = greater strength”. The increase in the muscular cross-section is caused by the increase in the cross-section of the muscle fibres (hypertrophy). The fundamental conditions for hypertrophy are that the equilibrium of the metabolism must be shifted in the constructive (anabolic) direction, and that enough building materials (mainly proteins) be present for muscle building. also needs to be supported by An adequate hormonal background also supports all this.

Hypertrophy in the skeletal muscle cell is preceded by an increase in the number of nuclei, because these ensure the production of an appropriate quantity of protein molecules. The sources of the nuclei are the so-called satellite cells, which are otherwise in a dormant state next to the muscle cells, and which, under the effect of load or injury begin to divide, and then, fusing with the myocytes, pass their nuclei to them. Therefore, as an effect of training, the number of nuclei in the muscle fibres increases, which thus allows the protein synthesis which ensures cross sectional growth (Egan, Zierath 2013; Radák 2016).

One of the most important, molecular-level generators of muscle hypertrophy occurring in reaction to load is the enzyme molecule mTOR (mammalian target of rapamycin), activated by mechanical stimuli, which, through several steps, induces protein synthesis in the skeletal muscle (e.g. Egan, Zierath 2013).

One of the principal hormones which positively influences the accretion of muscular cross section (muscle mass) is growth hormone, produced in the pituitary gland (the synthesis of which is augmented by the effects of training). Growth hormone (GH) plays a role, not only in improving maximal strength, but also in endurance, because, for example, it increases the value of VO2max (Radák 2016). The most important male sexual hormone, testosterone, produced in the testicles (in women, it derives from the adrenal cortex and from the ovaries), is also known for its strong anabolic effect: in the skeletal muscle it is a very effective agent in stimulating protein synthesis. It is interesting that the low intensity training reduces the production of this hormone, while high intensity training increases it. This is one of the reasons why athletes’ muscles in long-worktime, endurance-dominated, aerobic sports are not particularly big, while in sports of a more anaerobic-character, which require the exertion of high force, they are (Radák 2016). In addition to the above-mentioned points, other hormonal factors also play a role in favouring muscle hypertrophy, such as the insulin/glucagon ratio, or one of the mediators of the effect of growth hormone, the hormone known as IGF-1 (Insulin-like Growth Factor), produced in the liver under the effect of GH, which induces growth throughout the body, and in this way, stimulates protein synthesis in the muscle fibres (e.g. Radák 2016).

With adequate training exercises, muscle fibre hypertrophy can be purposely induced. These exercises typically consist of movements performed with great resistance (that is, with heavy weights) and in low repetition numbers, and are known as a means of improving maximal strength (regarding the specific exercises and their characteristics see, for example, Katics, Lőrinczy 2010; Radák 2016). However, in recent years, there has been increasing support for the idea that reinforcement training carried out with low resistance and high volume can, in given situations, augment the protein synthesis of muscles to an even greater extent than the great resistance and low volume load, which is commonly believed to be the best method to achieve it (Burd et al. 2010).

It must be noted, however, that in certain sports, strength has to be improved in a manner which avoids an increase in muscular mass (e.g. acrobatic gymnastics, long jump, pole vault, high jump, weight category combat sports).

5.1.2. The number of recruited motor units and the firing rate of motoneurons

As we could already see in the previous semester, one way to improve neuro-muscular coordination is to increase the number of motor units which are recruited during movement (Katics, Lőrinczy 2010; Radák 2016), and this will necessarily cause an increase in strength. Strength enhancement may also be provoked by a rise in the activity of the motor units’ motor neurons, that is, they produce a higher firing rate (e.g. Duchateau et al. 2006). We may remember that in the course of muscle contraction, the smaller, slow motor units are recruited first, and then the ever larger and stronger ones (and this principle is, in essence, also equally valid in the case of concentric, isometric and eccentric contractions [Duchateau et al. 2006]).

In the case of fast movements (Duchateau et al. 2006, Radák 2016) and those involving great effort (Fling et al. 2009), as a result of exercising, the increasingly larger and faster fibre units, which otherwise would be recruited later, will join the contraction sooner, so the time windows between the single recruitments will be reduced. If the time between the recruitments of motor units is so short that the units in question are practically recruited at once or almost at once, then the phenomenon can also be described as the realisation of synchronity between the motor units. (Although it seems that the synchronity of motor units is of a higher degree in trained than in untrained individuals, and these people are also stronger than untrained people, some authors doubt that the synchronization of the motor units is the cause of the increase in strength [e.g. Yao et al. 2000, Duchateau et al. 2006]). The improvement in muscle strength due to the change which occurred in the motor units generally takes place faster than hypertrophy, since a condition of the latter is a positive protein balance over a longer period (Egan, Zierath 2013).

So the improvement in the efficiency of the work pattern of motor units manifests itself during well-exercised movements: with exercise, the coordination, the strength, as well as the speed of the movements will increase.

5.1.3. Coordination between muscles

As another result of neuromuscular coordination, the degree of coordination between the work of the muscles which execute the given movement also increases with training, and with this, both strength and speed, as well as the fineness and the elaboration of the movements will increase. This coordination manifests itself in the phenomenon that the muscles acting in the same direction (synergist or agonist muscles) operate in synchrony, assisting each other to the greatest possible degree, while their antagonists carry out the relaxation to the most appropriate extent and in the ideal time.

5.1.4. Other factors

In addition to what has been discussed above, there are, of course, other factors which also determine the development of strength. As has already been mentioned, the genetic differences appearing in the type of muscle fibres limit who will become a good endurance sport athlete, and who will perform better in strength-dominated sports. Similar determinative conditions are age and sex, the effects of which on the skeleton, the muscular system and hormonal factors, have already been reviewed previously. Besides the condition of the body, the right lifestyle conditions – e.g. regenerational, nutritional – also have to be ensured in order to achieve a proper gain in muscular strength, since without sufficient and good quality sleep and adequate nutritional habits, the anabolic metabolism will not function well either.

5.2. Improvement of endurance

One of the extremes on the spectrum of training types is strength training, while at the opposite end we find endurance training. Studies generally focus on these two extremes, although the combination of the two – strength-endurance training – is also a popular training type is some sports.

A fundamental characteristic of training aiming to develop endurance is a relatively low intensity activity performed over a long time (even over several hours). (It is not our aim to review the various endurance exercises in detail; for this see Katics, Lőrinczy 2010; Radák 2016). As we have already indicated, endurance adaptation primarily occurs in a cardiovascular and a biochemical way, and is determined by many components (the operational efficiency of the energy generation systems, maximal oxygen uptake, characteristics of heat loss, diet, etc.). These parameters have been dealt with in detail in the chapters on energy production, so we will now review the relevant adaptational modes in a rough list.

The principal components of the development of aerobic endurance are the following (Radák 2016, Jamieson 2017; see also: Chapter 7.1., Table 4).

  • The degree of the vascularization of the heart increases.

  • The pumping capacity of the heart, that is, stroke volume, increases. Aerobic training carried out with low resistance augments the size of the cavity of the ventricles (both of the left and the right) (Baggish et al. 2008); this is called eccentric hypertrophy.

  • The resting heart rate diminishes.

  • The heart rate recovery time diminishes (the HR value returns to the resting value more quickly).

  • The decreased relative oxygen level in the skeletal muscle formed due to training induces the formation of blood vessels, so the degree of vascularization (capillarization) of the skeletal muscle increases, for which

  • the degree of arteriovenous oxygen difference (AV O2 diff) increases, that is, the muscular tissue extracts oxygen from the blood more efficiently.

  • The quantity of mitochondria in the skeletal muscle fibres grows, and

  • the efficiency of mitochondrial oxidation increases because of the increase in the quantity and activity of the enzymes which take part in the process (Hurley et al. 1984; Egan, Zierath 2013). Due to the increasing mitochondrial density and operational efficiency, the same ATP production of the cell involves a diminished oxidative stress per mitochondrion (that is, respiratory efficiency improves; Egan, Zierath 2013).

  • Due to all of these effects, the VO2max value increases.

  • The level of the lactate threshold (anaerobic threshold) increases, so trained individuals reach the average 4 mmol/litre lactate level in the blood – from which lactate concentration begins to rise steeply – at a higher work intensity (i.e. at a higher VO2max value; Hurley et al. 1984).

  • The efficiency of the utilization of fat under load increases (Turcotte 2000, Jeukendrup 2003). While working, a higher free fatty acid level can be measured in trained compared to untrained individuals.

Fat is the most energy dense compound among our organic nutrients, so it is logical that it is used by the body to produce ATP. However, since breaking it down also requires more oxygen than is required for carbohydrates, it is deployed as an energy provider only in the case of moderate intensity, aerobic training. The augmented oxygen uptake capacity (VO2max) of trained individuals ensures that they are capable of utilizing fat for ATP production even at a higher load intensity (Radák 2016). In the process of energy generation, the quantitative contribution of the two kinds of energy storing organic matter differ significantly.

As we have already seen, the fundamental principles, valid for fat utilization as an energy source during loading, are that fat utilization diminishes with increasing training intensity, it increases with increasing training time, and it is of a higher rate in trained than in untrained individuals (Jeukendrup 2003). From these it follows that the most “fat burning” type of training is low intensity, long duration training. At approximately one hour training time, 50–60% of the ATP production is provided by fat, and 40–50% by carbohydrates (from this point on, the utilization of carbohydrates decreases continuously, while fat utilization increases: with a 4-5 hour duration, 80–90% of energy production is provided by fat). In trained individuals, the 50–60% fat and 40–50% carbohydrate ratio referring to the one-hour period shows up far sooner, already roughly after half-an-hour of training (Radák 2016). The carbohydrate- and fat utilization ratio is also strongly influenced by the composition of food, the hormonal environment, the outside temperature and other factors (Table 3), and it shows a great variability across the population, but it is relatively stable within the individual (Jeukendrup 2003).

Table 3: The relative and absolute contribution of carbohydrates and fat to energy production during training, under the effect of various factors (Jeukendrup 2003, Table 1). (“↑”: increases; “+”: increases; “–”: decreases)

  • Up to approximately 65 % of the VO2max value the extent of the relative contribution decreases but the absolute contribution increases (above cca. 65 % of VO2max value both decrease).

** Kiens, Hawley 2011

*** Jeukendrup 2003, Tarnopolsky 2004

Resulting from these adaptations, aerobic endurance capacity improves. This can also be defined as the capacity to perform sports activity (or physical work) permanently, even at a VO2max ratio (VO2max %) which is kept high (it must be emphasized that this is independent of the concrete value of VO2max; Bosquet et al. 2002). It is important to note that training work aiming at the improvement of aerobic endurance capacity by definition lasts a long time, so due to this long duration, joint-, muscular- and tendon pain may arise (e.g. Radák 2016); therefore, a proper warm up before training and a moderate intensification of loading are of paramount importance.

The main components of the development of anaerobic endurance are the following (see also: Chapter 7.1, Table 4).

  • The higher intensity training increases the thickness of the wall of the left ventricle (that of the right does not change; Baggish et al. 2008), as the heart has to work against an increased peripheral resistance caused by the compressed blood vessels in the contracting muscles which exert a high force; this is called concentric hypertrophy.

  • The mitochondrial density increases in the myocytes (Gibala et al. 2009, Little et al. 2011).

  • The lactate tolerance and the efficiency of processes which reduce the lactate level, improves.

  • The proportion of non-contractile elements in the muscle (e.g. collagen) grows (Egan, Zierath 2013).

  • Due to local hypoxia, the vascular density of muscles augments.

  • The value of VO2max increases (Radák 2016).

The potential change in the capacity of the lung to take up air (vital capacity) is an interesting question. Several studies have found a link between physical activity and a large vital capacity (Doherty, Dimitriou 1997; Mehrotra et al. 1998; MacAuley et al. 1999), emphasizing the high lung function values of swimmers (Doherty, Dimitriou 1997; Mehrotra et al. 1998), while another study has concluded that physical activity does not increase vital capacity (Biersteker, Biersteker 1985). Nevertheless, even if there is a relationship between large lung capacity and sport, on the basis of these studies we cannot state for certain that sport causes the differences in the air uptake parameters of the lung, because it is possible that individuals with a smaller vital capacity simply do not do sports for pleasure, or they are ‘de-selected’ in the early stages of sports activities (MacAuley et al. 1999).

5.3. Improving speed

Speed is a property which plays an important role in most sports, and which fundamentally depends both on the abilities of the muscle and on the component contributed by the nervous system. The speed of muscles is strongly determined by the relationship between their own mass and that of the body part they move, that is, their relative strength on the one hand, and their fibre composition, i.e. the ratio of their fast and slow motor units, on the other. How fast and in what pattern the motor units and the synergistic-antagonistic muscles come into action depends on the state of development of the coordination level between the nervous and the muscular system (neuromuscular coordination). This parameter is the greatest determining factor in the level of technical execution, which, in turn, strongly influences speed.

During training for speed it is a basic requirement that the fast motor units be recruited soon and in a coordinated fashion. Since the activation of the large, fast motor units, controlled by motoneurons with a high threshold, needs big stimuli, during speed-improvement training sessions, exercises performed with high resistance and/or maximum (or close to maximum) speed will yield the best results. Knowing that these fibres are also more easily fatigued, the appropriate scheduling of workout time is also of key importance: the most effectively utilized exercise will be the one executed at the beginning of the session, in a rested state, and not with a high number of repetitions. Given, however, that during high intensity training, work is basically done in the anaerobic alactacid and anaerobic lactacid ranges, the rapidly depleted stores of which are also regenerated quickly, there is no need for single workouts to be separated from each other by a long time (it is even possible to work out twice a day).

Different manifestations and components of speed can be recognized, which will be reviewed schematically, following Radák (Radák 2016).

It is basically the nervous functions which determine the following aspects of speed.

  • One of the best measurable components of speed is reaction time. This means the time which passes from the perception of the signal to the initiation of the reaction, so it is composed of the information transport time of the afferent and efferent pathways of the nervous system which perceives the signal, the signal elaboration time of the centre, plus the time required for synaptic transmissions. Its value (for acoustic and visual stimuli) usually falls between 0.16 and 0.2 seconds, and it cannot be brought under 0.1 seconds, even with extensive practice.

  • The ability of decisional speed is also of outstanding importance if we talk about sports based on decisional situations. In sports which involve reacting to an opponent’s movements as quickly as possible (ball games, combat sports), this component of speed plays a decisive role in the outcome of the match. To shorten the response time of the opponent, movement formations with a pre-fixed sequence, “figures”, and combinations are composed and employed, which, when perfected, diminish the chance of the opponent reacting, and thus present the opponent’s decisional speed with a serious challenge.

  • The speed of movement learning determines the level of technical execution relative to exercising time; therefore, it has a very important, even if indirect, relationship with speed.

The following components of speed all depend on factors related to both the muscular and the nervous system.

  • Movement speed is the speed of non-locomotor movements (i.e. position-changing movements carried out with the arms, the legs, the torso and the head).

  • Maximum locomotor speed means the speed of progressive motion generated by cyclically performed movements, that is, the maximal speed of running, swimming, cycling, etc.

  • The capacity for acceleration shows how much change in speed is achieved by the individual in a unit of time or distance.

  • The capacity for deceleration plays an outstanding role in sports involving changes in position – such as ball games and combat sports –, and it determines the capacity to carry out sudden changes in direction and to dribble in sports like football. We may remember that braking – especially in movements of high force and speed – involves significant eccentric muscle work.

5.4. Developing articular mobility

The proper motion range of joints ensures the precise execution of movements, and at the same time, it lowers the probability of the occurrence of injuries. Reduced articular mobility range can impair both; an increased range of mobility generally broadens the movement repertoire, and enhances the technical level of sports movement, but at the same time, it also increases susceptibility to injuries. Finding the optimal range of movement is not always an easy task.

The development of articular mobility is desirable to different extents in different sports. Gymnastics, aerobics and other sports of an acrobatic nature require a very high degree of flexibility; in other sports it can be an advantage (e.g. fencing, tennis, boxing, ball games, combat sports, slalom skiing etc.), while in certain types of activities the relative contribution of joint looseness to performance is small (cycling, running), or can even be zero (for example, motor racing).

Articular looseness may be generated by stretching. Stretching consists of two fundamental components: the stretching of the tissues, and the attenuation of the nervous system’s myotatic reflex (Radák 2016). We can remember from our biological studies that the myotatic reflex appearing in the muscles is a proprioceptive reflex, and can be defined as the contraction of a muscle in reaction to stretching. This reflex initiates from muscle spindles, and, through spinal cord interneurons, it stimulates the contraction of the muscle which is subjected to stretching, while it inhibits contraction in the antagonist muscle. By practising stretching, we also diminish the intensity of this reflex. If the stretching exercises are carried out slowly, the process is more effective, because a too rapid movement activates the myotatic reflex more easily (Radák 2016).

The stretching of the tissues means the stretching of the muscles on the one hand, and of the tendons and ligaments on the other. The two sorts of tissue (muscular tissue and connective tissue) react to this exercise in different ways. The stretchability of connective tissues with a matrix formed by collagen fibres (tendons, ligaments) is much more limited than that of muscular tissue. Stretchability is, of course, also influenced by accessory factors, such as age, temperature and fitness (Radák 2016).

Stretching can be carried out both in a static way (without additional movements), or dynamically (for example, with swinging movements). With the development of training science, different techniques have evolved to make stretching more effective (see, for example, Sharman et al. 2006, Bradley et al. 2007), the discussion of which is beyond the scope of this work.