Introduction

Physical inactivity has been identified by the World Health Organisation (WHO) as the fourth risk factor for mortality after arterial hypertension, tobacco consumption and high blood glucose levels. Similarly, overweight and obesity, which are secondary manifestations of physical inactivity, increase the probability of certain diseases and are responsible for 5% of world mortality.1

There is now consensus in the scientific literature that regular physical activity (PA) during infancy and adolescence is one of the most effective means of improving and preserving the health of young people and adults. Improving physical condition during youth, more specifically cardio-respiratory condition and muscular strength, has been proven to improve risk profiles for suffering a metabolic disease, increasing bone mineral density, reducing the symptoms of depression,2 improving children’s emotional, cognitive and social wellbeing3,4 and also increasing their motor competence.5

In spite of the evidence described, modern society is characterised by low levels of PA during youth.6,7 With the aim of identifying the degree to which there is a deficit of PA in the young, some authors use the term exercise deficit disorder (EDD). EDD is the term used to describe a deficit in healthy exercise due to low levels of regular physical exercise during youth.8-10

On the other hand, we find evidence which indicates that MC, understood as the capacity to contextualise motor skills in response to sports or everyday problems, leads to an improvement in healthy physical condition over the medium and long terms.11-13

Accepting the evidence that shows the need to increase PA in infancy and adolescence, together with the relationship between MC and a healthy physical condition, we ask ourselves: what relationship exists between MC deficits during childhood and a lifestyle that includes PA over the short to long term? Are there any validated and reliable methods for the detection of EDD? Could strengthening MC during childhood and adolescence using integrated neuro-muscular training (INT) be the key to promoting a healthy lifestyle throughout life?

This work has three aims: (i) to describe the relationship between MC and the practice of healthy PA; (ii) to justify the need to establish a diagnosis for EDD, and (iii) to propose INT as the methodology for improving physical condition and MC in children and adolescents.

Motor competency: the prevention of exercise deficit disorder. Towards a healthy lifestyle

The development of motor competency

MC is described and defined by several authors.13-15 In this paper it is understood to be the management and expression of motor skills (MS) as a contextualised response. In a specific context, the subject has to evaluate the quality of his motor repertoire to effectively and efficiently resolve the problems that arise in the everyday environment and sports settings. For example, a vertical jump is the MS that would permit the subject to display competence in multiple situations: catching a rebound in basketball in an attacking 1 × 1 situation, carrying out a blocking manoeuvre in volleyball in a defending 1 × 2 situation or crossing over an obstacle in his path while walking in the mountains… Nevertheless, the perfect execution of a motor skill does not mean that a subject would be competent in all of the situations requiring the theoretical response of a vertical jump. In fact, efficacy also depends on the decision taken at the time, as well as how the skill is adapted and the capacity to adapt it.

Following the logic used to date, MS are clearly conditioned by the capacity to coordinate as well as conditional capacities. Capacities are motor predispositions that subjects have to develop through skills. I.e., there is a relationship of interdependency between both concepts. For example, leg strength is increased by jumping, among other skills. And in turn, the quality of jumping improves with increasing leg strength. To continue with this example, by jumping we improve the neuromuscular coordination of the muscles involved in the skill, and at the same time this neuromuscular improvement increases the quality of the jump.

The concept of MS defended here can only be explained on the basis of complexity, in the understanding that intervention in one subsystem affects the system as a whole.16,17 In connection with what is shown in Figure 1, this paper centres on the need for motor richness and quality, which can be gained by developing fundamental motor skills (FMS), with emphasis on capacities involving coordination (more specifically neuromuscular control, which is defined by Fort and Romero18 as the activation of exactly those muscles which enable a coordinated and effective action during physical and sports activities) and in conditional capacities (specifically strength and stamina).

Figure 1. The relationship between motor competence, skill and capacity.

The basis of motor competency: basic motor skills

Motor development involves the changes in human motor behaviour throughout life, the processes underlying these changes and the factors that affect them.19 The development of MC is therefore associated with the period of life when growing and maturing take place, although it also includes the regressive periods associated with ageing.

Few models explain motor development (e.g., Gallahue and Ozmun; Clark and Metcalfe).15,20 We suggest a model to explain motor development (Figure 2) that includes concepts from the Gallahue’s Triangulated Hourglass15 and Mountain of Motor Development20 models.

Figure 2. Motor development. Adaptation of the models Gallahue’s Triangulated Hourglass (Gallahue and Ozmun, 2006)15 and the Mountain of Motor Development (Clark and Metcalfe, 2002)20.

Gallahue and Ozmun describe MC as a process and product. The process includes the main factors which influence the development of MC: (i) individual factors (hereditary and biological); (ii) contextual factors (previous experience, learning and socio-cultural factors, and (iii) factors associated with the task in question (physical and mechanical characteristics, cognitive demand). On the other hand, the result emerges from an independent relationship between the said factors and the growth and maturing of an individual. This relationship defines a critical time of learning during the years of development, in which children and young people are more sensitive to adaptation due to education or training.21,22 On the other hand, the model of Clark and Metcalfe includes the idea that an individual develops only a few skills, and these to different levels.20

Figure 2 defines 5 phases of motor development, each one of which is limited by an age range during which individual factors must be taken into account,15 while these phases in turn take the form of stages of development manifested in a particular way for each skill and individual.

The phase of movements and reflexes lasts from birth to the end of the first year of life, in which involuntary movements aid learning about the body and its relationship with the environment. This is followed by the phase of rudimentary movements which lasts until the age of 2 years old, during which reflexes tend to disappear (the reflex inhibition stage) and voluntary movements commence, although they are uncontrolled and coarse (the pre-control stage). The first sign of the said stage is walking, which is the main resource for exploring and manipulating the surroundings. As a result of this, many children are able to walk unaided at the end of their first year of life. Following natural development, the next phase is that of FMS, in which each skill passes through three developmental stages (the initial stage, the elemental stage and the mature stage). Locomotion skills are first developed and expanded (e.g., to include running, jumping and leaping) together with balance (e.g. changing rhythm, turning). When strength, balance and motor coordination improve, other skills emerge such as galloping and sliding. Subsequently, with time and practice, eye-hand and eye-foot coordination emerge and as a result of this children start to develop skills that are commonly known as object control skills (e.g. passing, receiving, hitting and throwing). However, it has to be underlined that the development of each skill follows its own path, and that therefore different skills at different stages of development coexist. Children’s motor richness may present FMS in isolation or in combinations.19,23,24 Subsequently, the said MS will become specialised depending on sports or the context in which they are needed, giving rise to specific specialised motor skills (SMS).

We explained MC on the basis of motor development, the process in which basic motor skills play a relevant role, as they function as the foundation for the development of complex and specific motor skills which are varied and context-dependent. Many studies have centred on the description and classification of basic motor skills.19,24-26 We take the one by Gallahue and Ozmun as our reference. This classified FMS as locomotor, object manipulation and balance15 (Figure 3).

Figure 3. Fundamental motor skills (FMS).

The relationship between motor competence and health

In 2010 the WHO recommended that children and teenagers should undertake 60 minutes per day of moderate or vigorous PA. However, recent epidemiological reports indicate that level of PA are falling in adolescence and youth,6,7 and that this sedentary behaviour continues into adulthood.27 In fact, data of the IDEFICS study (2014) obtained in the Spanish population using accelerometry indicate that only 30% of boys and 12% of girls fulfil the recommendations for 60 minutes of PA per day.28 It is important to underline that this reduction in PA seems to occur at the age of 6 years old,7,29 after which the development of FMS requires the intervention of expert professionals who provide instruction and guidance for more complicated activities. A recent meta-analysis indicated that inclusion in PA programs aiming to offer experiences rich in FMS developed by physical education specialists favouring the development of MC in young people.7

FMS are elemental units of activities that are necessary for more complex motor activities, including sports and active leisure activities. Clark and Metcalfe state that FMS are the “base camp” of the mountain which lead to the development of SMS.20 Although PA in childhood contributes to increase energy expenditure, it is even more important to underline that it contributes to the creation of a motor repertoire.15

Some studies show a positive relationship between the practice of PA and MC in children.30-34 Thus children who are not exposed to environments with opportunities to improve their FMS tend to be less active during adolescence. This reality may become manifest in sedentary lifestyle habits during adulthood.12,19

It is therefore possible to conclude that there is a relationship between MC and healthy habits involving PA (Figure 4) over the short and long terms. MC favour physical fitness and may reduce the risk of injuries in connection with young people’s and adolescents’ activities.13 Additionally, a good MC helps young people to have a better repertoire of motor options in which they feel competent to decide on their lifestyle.13,15,33 Longmuir et al. broaden this idea to state that physical education must affect MC, but that it must also affect motivation and self-confidence, together with knowledge and understanding of the value of following a healthy lifestyle.35

Figure 4. Children who undertake integrated neuromuscular training that includes a wide variety of fundamental motor skills (FMS) with the aim of improving their health and motor and sports skills may reduce exercise deficit disorder and attain a healthy lifestyle during adolescence and their adult life.

In the opposite sense, motor incompetence or low-level acquisition of FMS leads to a feeling of failure, low self-esteem and insecurity in motor activities.36 These feelings may lead to inhibition or the gradual cessation of activity which in turn will lead to more incompetence and less adherence to PA. This reaction may also be explained by the self-determination theory of Ryan and Deci (2000), in which competence together with relationships and independence are the three basic psychological needs that individuals have to satisfy to be intrinsically motivated to perform an activity.37

Although there are many ways of increasing young people’s levels of PA, not all of them contribute equally to increasing MC. For example, walking or running for more than one hour per day (as recommended by the WHO for an active lifestyle) does not favour the development of MC during childhood, as it only affects one type of FMS.

The bibliography shows signs that INT is a type of PA which works on sequences of movements that are present in a wide variety of organised and non-organised physical activities.38,39. INT is defined as a physical exercise program that includes tasks requiring strength, stamina and general physical conditioning (e.g., basic motor skills) as well as specific skills (e.g., agility, dynamic stabilisation, coordination and plyometrics) with the aim of improving health (e.g., reducing the incidence of injuries, increasing cardio-respiratory capacity or reducing obesity) and increasing performance using FMS and SMS.38,40

Is it possible to identify children with low motor competence or exercise deficit disorder?

Exercise deficit disorder

Tools now exist that are able to identify physical inactivity in young people. However, in this paper and in accordance with what has been developed to date, we propose to use a broader term, EDD.

EDD is applicable to those children and adolescents who present low levels of regular PA (< 60 min/day) seen in terms of health8,10 as well as low levels of MC for their degree of maturity. Thus while a child may fulfil the recommendations for daily PA (> 60 min/day), he may have failed to develop the MS that correspond to his degree of maturity.

In connection with the previous paragraph, and due to the symbiotic relationship between PA and MC in youth, it is very important that as well as aerobic activities, the recommendations for PA in infancy also include strength and neuromuscular control exercises21,22,38 (Figure 4). The recommendation for PA centred on suitable MC for age that is safe, effective and enjoyable should be the treatment for EDD.

Although EDD may be manifested by signs, symptoms, measurements and values which are often used to diagnose certain diseases (e.g., the body mass index, lung capacity, HR, VO2max in blood or glucose metabolism), there is no specific test or marker for the diagnosis of EDD.10 Nevertheless, the Canadian Assessment of Physical Literacy test (CAPL) could be evaluated for this purpose. In one dimension it assesses physical competence using a test of stamina, a motor skills test, a strength test (grasping, the trunk and the legs), the body mass index and waist perimeter measurement.35

In any case, to identify young people with EDD associated with negative consequences for their health over the short to long terms, tools are required that would also quantity PA in terms of energy expenditure (> 60 min/day), evaluating strength and neuromuscular control necessary for undertaking their everyday and sports activities in a competent way.41,42

Improving neuromuscular control and preventing exercise deficit disorder

The development of MC is closely linked to the concept of neuromuscular control, which is defined as the neuromuscular activation that is necessary to undertake motor activities effectively and in a coordinated way.18 In turn, neuromuscular control is expressed in a way that depends on the biological maturity and development of the central nervous system of children and adolescents, as well as on the quality of the motor experiences lived to date.19 The central nervous system undergoes a massive increase in myelination and synaptic connections between the ages of 2 to 5 years old, and this process does not end until sexual maturity or even adult age.43,44 Taking this information into account, experiences which encourage neural adaptations may be beneficial for the development of MC, before puberty above all, when the central nervous system is higher in plasticity, even though it continues during the years of adolescence.

During puberty the neuromuscular control system undergoes a slight regression due to the peak in growth speed (PGS), which is defines as the maximum rate of growth in height.44 The chronological age at which PGS occurs varies considerably among young people, although it normally occurs around the age of 12 in girls and 14 in boys.45,46 On the other hand, it is important to take into account the fact that the fastest increase in body mass parallel to the greatest rate of variation in weight occurs approximately 12 months after the growth stage (PGS).21,47 This rapid increase in the skeletal system and subsequent increase in body weight lead to high stress and a high level of demand for the neuromuscular control system, as it has to adjust to the new structures (e.g., muscle tissue and fat). In sports this weight variation will make it possible to create new structural adaptations (e.g., muscular hypertrophy) and as a result of these muscular strength and power will improve.48 That is why this period of time is a stage during which there is a high risk of sports injuries, given that the muscle power developed is not always accompanied by increased neuromuscular control. The great development of the skeleton and muscles during puberty is therefore not accompanied by the corresponding neuromuscular adaptation, and biomechanical patterns which are mainly harmful may be developed due to this during high intensity motor and sports activities.49,50 In fact, mechanical abnormalities (such as dynamic valgus of the knee) during landing after jumping, changes in direction or decelerations have been associated with a high rate of serious lower limb injuries in adolescents (such as injury to the anterior crossed ligament).48,51

A practical result of the previous paragraph is that the recommendation now is to commence INT during infancy and pre-puberty, before the period of PGS48 and precisely during the stage when the FMS are developed. The purpose of the said training is to improve the efficiency of the MC. A strong base here will make it possible to progress with more specific and demanding MS, based on and for the benefit of health.

Proposal for work to improve motor competence in young people: integrated neuromuscular training

In spite of the increase in the number of children and adolescents who hardly follow the recommendations for healthy PA, and as a result the reduction in MC among our young people, many studies have shown that integrated neuro-muscular training programs improve neuromuscular control in young people (e.g., FMS).38,39 Table 1 shows the effects of INT programs on young people described in the scientific literature.

In turn, and over recent years, many studies have shown the efficacy of work of this type in reducing the risk factors for neuromuscular and biomechanical injuries, as a result of which it also reduces the number of sports injuries in children and young people.51-54 Moreover, it is important to take into account the fact that children with good neuromuscular control and good MC increase their self-confidence and self-esteem during the practice of PA, which associated with the reduction in the risk of suffering sports injuries may increase adherence to physical exercise.

As we pointed out above, INT is defined as a program that includes general and specific tasks with the aim of improving health and performance of MS and sports.38,40,55 INT has to initially lead to the creation of a broad base of FMS (e.g., jumping, turning and passing)15 to then progress to the SMS of each sport (such as the backhand in tennis or throwing to score in basketball) or those intrinsic to an active lifestyle (such as dancing or riding a bicycle). Thus at the moment children and adolescents are able to confidently undertake FMS they will be able to go on to carry out more complex tasks, ones involving greater intensity and neuromuscular demands. INT must include the variety, progression and recovery intervals that are suitable for each task.39,56 In this way, the keystone of INT is to propose suitable MC tasks for each individual, directed by qualified professionals who understand the fundamental principles of motor development in children and adolescents,57 as there is no single INT protocol which is suitable for all individuals (depending for example on the biological age, MC level, sex, genetic factors or neuromuscular deficits) of each child or adolescent.

Taking into account the principles of motor development, Myer et al. recommend introducing INT centred on MC between the ages of 5 to 9 years old, using games as the methodology to bring about improvement.48 The INT continues to become gradually more difficult and intense in its tasks during puberty, using recreational and multiple-sport PA. In the stage after puberty we will start to include specific training for the development of MS in selected sports or PA. Figure 5 shows the progression of INT based on current scientific evidence from pre-puberty to post-puberty.

Figure 5. Progression in integrated neuromuscular training. Adapted from Myer et al., 2013.48

The bibliography which examines the effects of INT on physical performance and injury prevention includes multiple contents on neuromuscular training (dynamic stability, coordination, strength, plyometrics, speed/agility and stamina).40,51,58 In spite of this, it is hard to decide which of them contributes more or less to improving FMS initially followed by SMS. Figure 6 shows how the different components of INT are able to help consolidate fundamental motor skills in the first place, followed by the development of SMS in a safe and enjoyable way.59

Figure 6. Integrated neuromuscular training components. Adapted from and with the permission of Fort-Vanmeerhaeghe et al., 2016.59

Conclusions and practical implications

Although the factors which affect the practice of PA by young people and adolescents are complex, it seems that MC is able to encourage a healthy lifestyle over the long term while reducing the risk of injury. Young people with signs of EDD have to be identified, assessing how much PA they do per day, as well as the variety and quality of the same. It will therefore be necessary to offer physical education specialists the tools that will establish this diagnosis.

Although motor incompetence in childhood and adolescence predispose individuals to EDD, the good news is that this can be combated using INT. By including INT in formal or informal educational programs for childhood and adolescence, we work to prevent physical inactivity in the adult population.

The person in charge of diagnosing EDD and designing and developing the INT programs must be a specialist in physical education, as they must be expert in the development of MC as the basis for an active and healthy lifestyle.

Conflict of interests

The authors have no conflict of interests to declare.

Received 12 September 2016;

accepted 7 November 2016

* Corresponding author.

E-mail address: afortvan@gmail.com (A. Fort-Vanmeerhaeghe).