Making Physical Activities a Part of a Child’s Life

Abstract

Children will grow and develop to their fullest potential by learning from others, imitating, playing, engaging in activities, and socializing. There are several benefits to engaging in regular physical activity. Engaging in exercise habits or participating in sports organizations strengthens abilities, hand-eye coordination skills, functional movement skills, as well as strength, academic performance, and self-management skills in daily life, have higher bone mineral density and lower risks of cardiovascular issues, overweight, or obesity in young adulthood. It is important to note that tests are based on movements that are enjoyable and commonly performed by children aged 5–12 years as part of their daily activities. In children’s Resistance Training exercises, strength-building often involves movements such as frog jumps, bear crawls, crab walks, kangaroo hops, and one-leg hops. There is a lot of research data indicating that physical activity can benefit some children with congenital diseases, too.

1. Introduction

A healthy child is characterized by growth and development as they age. Parents, healthcare professionals, school teachers, and relatives—all individuals in a child’s environment—must cooperate and coordinate to help children reach their optimal potential. Children will grow and develop to their fullest potential by learning from others, imitating, playing, engaging in activities, and socializing.

Physical activity (PA) plays an important role in a child’s life, even into their later years, and it has a positive impact on a child’s mental health [1]. Physical activity has been proven to contribute positively to social, emotional, and cognitive development [2]. Research by Iivonen and Zeng also shows that the development of motor skills is greatly influenced by physical activity [3, 4]. The development of motor skills significantly affects an individual’s ability to fulfill daily life tasks. The relationship between physical activity and motor development is not unidirectional but reciprocal. To achieve their sensory and motor abilities, children require experiences from their everyday lives. Therefore, childhood is a critical period of development that will shape their future lives. The relationship is seen to be bidirectional, not unidirectional, in a child’s life [5]. From the early stages, children require experiences for their sensory and motor abilities, making childhood a critical period for their development [5].

Does a child’s life with different health statuses result in different physical activity needs? And what about age? Do children’s needs change as they grow older?

Over the past few decades, children’s physical activities have undergone dramatic changes. Motoric physical activities have been replaced by indoor activities, and sometimes even just playing with gadgets. It is rare to see children playing in fields or mountains after school, exploring the outdoors, and searching for fruits in the forest. This is likely due to the crowded and built-up environment and the increasing amount of schoolwork that requires children to spend time in front of laptops.

The World Health Organization (WHO) defines physical activity as any bodily movement produced by skeletal muscles that requires energy expenditure. Physical activity includes all activities during leisure time, work time, and when moving from one place to another. It encompasses moderate to vigorous activities, including sports. WHO has recommended specific amounts of physical activity based on age and specific populations, taking into account brain development, muscle capacity, cardiovascular and respiratory function, sleep needs, and nutritional requirements. For children under 1 year old, physical activity should be divided into various time intervals and performed on mats or the floor. Let infants engage in supervised tummy time for at least 30 minutes, divided into several intervals. When the baby is awake, it should not be confined or restrained for more than 1 hour at a time, such as when sitting in a high chair, stroller, or being carried. Their sleep needs should be fulfilled, with 14–17 hours for infants aged 0–3 months and 12–16 hours for infants aged 4–11 months. Children aged 1–2 years should spend at least 180 minutes physically active and engaging in various activities with moderate to vigorous intensity. Signs of being in the moderate intensity zone include being breathless but still able to speak. On a scale from 0 to 10, where 0 is sitting and 10 is vigorous activity, moderate intensity is around 5–6. It is not recommended to let children sit quietly, watch TV, or play with gadgets for more than 1 hour. They should fulfill their sleep needs, which range from 11 to 14 hours per day. For children aged 3–4 years, physical activity should be performed for at least 180 minutes per day, including 60 minutes of intense activity. The rule of not allowing more than 1 hour of TV watching or gadget use still applies. Quality sleep should be maintained for 10–13 hours per day, for children and adolescents aged 5–17 years, at least 60 minutes of moderate to vigorous intensity physical activity should be performed daily. These activities will strengthen their muscles and bones [6].

Motor development milestones are essential indicators of a child’s physical growth and motor skills. The World Health Organization (WHO) provides a comprehensive guide for tracking motor development in children. Here is a summary of motor development milestones based on the WHO reference (Table 1) [6].

Age	Gross Motor	Fine Motor	Sensory Development
0–3 months	Lift and turn your head briefly when lying on the stomach.	Grasps objects when they touch their hands.	Shows visual and auditory responsiveness to stimuli.
	Moves arms and legs in a random manner.		Begins to follow moving objects with their eyes.
4–6 months	Rolls over from back to stomach and vice versa.	Reaches for and grabs objects voluntarily.	Reaches for and explores objects with their hands.
	Sits with support and begins to support weight on legs when standing.		Begins to develop depth perception.
7–9 months	Crawls or scoots on the floor.	Transfers objects from one hand to another.	Uses hands and mouth to explore objects through touch and taste.
	Pulls up to stand and cruises along furniture.	Begins to use thumb and fingers to pick up small items.	Shows increased awareness of their surroundings.
10–12 months	Take first independent steps (walking).	Uses a pincer grasp (thumb and forefinger) to pick up small objects.	Uses a pincer grasp to pick up small objects.
	Stands momentarily without support.	Attempts to scribble with a crayon or marker.	Begins to show an interest in exploring textures and shapes.
12–24 months	Walks confidently and begins to run.	Build a tower of two to four blocks.
	Climbs stairs with assistance and kicks a ball forward.	Uses a spoon to feed themselves.
24–36 months	Runs more smoothly and jumps with both feet off the ground.	Draws simple shapes like circles and lines.
	Climbs stairs with alternate feet and pedals a tricycle.	Begins to use safety scissors.
36–60 months	Hops on one foot and balances on each foot for a few seconds.	Draws more complex shapes and begins to write letters.
	Throws and catches a ball with increased accuracy.	Strings beads and manipulates small objects with precision.

Table 1.

Motor development milestone in children [6].

Thirty studies were included in the meta-analysis, resulting in a total of 21,686 participants assessing fitness in children ages 3–18 years for more than 1 year of follow-up. Does muscle fitness affect health status even in the future? Meta-analysis found the effect size to be significant, with moderate to large results, namely muscle fitness, negative for increases in body mass index, skinfold thickness, homeostasis model assessment, insulin resistance estimation, and triglycerides. Cardiovascular disease risk score (r = − 0.29; 95% CI - 0.39 to - 0.18) and bone mineral density (r = 0.166; 95% CI 0.086 to 0.243). The results of the study indicate when a child starts exercising or physical activity that has been meaningfully active since childhood, will have benefits for maintaining muscle fitness, maintaining body weight so obesity does not occur, reducing the possibility of diabetes mellitus, heart attacks, and osteoporosis [7, 8, 9, 10].

The American Academy of Pediatrics (AAP) states that the development of skills such as jumping, leaping, kicking, and throwing significantly influences cardiovascular function, both during childhood and into adulthood. Engaging in exercise habits or participating in sports organizations strengthens abilities, hand-eye coordination skills, functional movement skills, as well as strength, academic performance, and self-management skills in daily life [11].

2. From free play to sport

Recent research on children’s physical activity levels has shed light on the significance of achieving 12,000 steps a day. Studies have shown that encouraging children to engage in regular physical activity, such as walking, can have numerous health benefits. The recommended 12,000 steps per day for children are associated with improved cardiovascular health, increased bone density, and enhanced motor skills development. Moreover, regular physical activity can help combat the growing concern of childhood obesity and promote overall well-being. To achieve this target, it is essential to create environments that encourage and facilitate physical activity, such as safe walking paths, parks, and playgrounds. By promoting a culture of movement and play, we can empower children to lead healthier and more active lives, setting the foundation for a lifetime of positive health outcomes [12].

In my clinical experience, healthy children tend to be physically active in their daily lives. Such habits should be guided by parents and educators to be more beneficial, not only for their daily lives but also for achieving success. This applies to both typically developing children and those with special needs.

Based on observations, discussions with various cases, and research from the American Academy of Pediatrics (AAP) in Physical Activity Assessment and Counseling in Pediatric Clinical Settings, it is stated that a child’s development of structured sports activities such as running, jumping, kicking, and throwing is strongly related to cardiovascular health, both in the present and as the child grows into adulthood. Engaging in structured physical activity habits enhances physical abilities in terms of hand-eye coordination, functional movement skills, strength, academic performance, self-regulation, and general life skills. This is significant for socialization [13]. It starts with free play patterns adjusted according to a child’s developmental milestones, abilities, talents, and sometimes considering gender. Thus, the patterns developed from activities at home can be transformed into organized sports activities. A child’s abilities will improve when exercise habits are also incorporated into their school curriculum, especially when they can join sports organizations they enjoy. They can also be encouraged to explore competition within their age group.

Programs are designed to combine free play patterns for kindergartners and first-graders with specific skill-based movements. For example, a child may be trained in the skill of running while carrying a ball and how they can develop cooperation skills with their peers. The progress of these developing abilities can be evaluated within 4 months [14].

Children with athletic talents or those engaged in sports with specialized coaches will naturally feel more motivated and challenged to further develop their physical activity and chosen sport. It is worth noting that physical activity also improves cognitive performance and academic achievement in school [15].

Specifically, one study found that children who actively participated in a sports club had a positive association with good math scores [16].

Markel DL states in his research that a child is ready to face learning and the integration of physical activity into a more diverse skill set and better concentration for achievement when they have reached the age of 6. At that stage, children can be directed toward more structured sports aiming for achievements [17].

While looking for research statements, it is known that individuals engaged in sports are more resilient to stress and less prone to suicidal ideation. However, caution must be exercised regarding the use of steroids.

There are several advantages and disadvantages of using steroids (Table 2).

Advantages	Disadvantages
Better muscle development	Bulimia, anorexia
Reduce fatigue	Stunting
Better physique	Bigamerexia
	Tendency to use other substances such as alcohol, cocaine, injected drugs, cigarettes (Jesson) and having suicidal thoughts [18, 19]
	Hepatic system: Liver toxicity [20], hepatocellular adenomas
	Cardiovascular: Increased of low-density lipoprotein, Decreased high-density lipoprotein
	Reproductive system: Testicular atrophy and decreased spermatogenesis
	Musculoskeletal: stiffening of tendon, absorbs less energy, and likability to fail during activity

Table 2.

Advantages and disadvantages of steroids usage in children [21, 22, 23].

There may be a connection between the use of Anabolic Androgenic Steroids (AAS) and poor academic performance. In a large national study, DuRant and colleagues [21] stated that students who reported below-average academic performance had a significantly higher prevalence of AAS use compared to students with average or above-average academic performance. However, two other studies [22, 23] reported no relationship between academic achievement and AAS use. Further research is needed to explore this question.

3. The importance of test batteries to measure physical fitness in children

Childhood physical fitness is a crucial aspect of overall health and well-being. With the prevalence of sedentary lifestyles and the rise in childhood obesity, it is more important than ever to assess and promote physical fitness in children. Test batteries, consisting of standardized assessments, play a pivotal role in evaluating various aspects of a child’s physical fitness. These batteries enable educators, healthcare professionals, and parents to gain valuable insights into a child’s overall fitness level and identify areas for improvement. This article explores the significance of test batteries in measuring physical fitness in children and how they contribute to developing targeted interventions to support their health and fitness journey. Some test batteries for children aged 5–12 years (measuring physical fitness in children who are 5–12 years old with a functional and easy-to-administer test battery) [24].

The wide range of abilities in children as they grow older sometimes makes it difficult to assess their physical fitness and determine suitable testing methods for each age group and how to compare them across different age ranges. In a research report, Ingunn Fjortoft and colleagues presented an interesting review of tests that can be performed. These tests are simple and engaging while being able to evaluate physical fitness levels. It is important to note that these tests are based on movements that are enjoyable and commonly performed by children aged 5–12 years as part of their daily activities. The tests are as follows:

3.1 Standing board jump

Leg power is a crucial component of physical fitness, as it directly impacts a child’s ability to perform daily activities, sports, and recreational pursuits. The Standing Board Jump provides a reliable measure of leg power, giving valuable information on a child’s ability to generate force with their lower body muscles. This information can be useful in designing targeted exercise programs to improve leg strength and power [25].

The Standing Board Jump is a fitness assessment that measures a child’s explosive leg power. It involves the child standing on a firm surface with feet shoulder-width apart, ready to jump. They are asked to jump forward as far as they can while swinging their arms for momentum. The distance jumped is then recorded and serves as an indicator of the child’s lower body strength and power. One of the primary advantages of the Standing Board Jump is its simplicity and safety. Unlike more complex fitness tests, this assessment requires minimal equipment and space, making it easy to administer in various settings, such as schools, community centers, and sports clubs. Moreover, it is a non-invasive test that poses little risk of injury to the child, making it suitable for children of all fitness levels [25].

Cut off value for Standing Board Jump (cm) test, result: 122.54 Standard Deviations (SD) 19.41.

3.2 The 7-meter two-foot jump test

Explosive power is an essential component of physical fitness, especially in activities that involve quick bursts of energy, such as sprinting, jumping, and certain sports movements. The 7-meter two-foot jump test focuses on explosive power, providing valuable data on a child’s ability to generate force rapidly, which has practical implications for their performance in various physical activities [25].

The 7-meter two-foot jump test yields objective and quantifiable results, making it an ideal tool for evaluating physical fitness in children. The distance jump can be easily measured and recorded, allowing educators, coaches, and healthcare professionals to track a child’s progress over time. These objective metrics provide valuable feedback to children, motivating them to set goals and strive for continuous improvement in their physical fitness. The 7-meter two-foot jump test requires the child to jump as far as possible using both feet, with the goal of covering a distance of 7 meters (approximately 23 feet) as quickly as they can. This test evaluates lower body strength, power, and coordination, as the child must generate explosive force to propel themselves over the distance. It is a dynamic assessment that mirrors real-life movements, making it a practical and engaging way to measure a child’s physical fitness [25].

Cut-off value for jumping a distance of 7 m on 2 feet as fast as possible (s) test, result: 3.87 SD 0.59.

3.3 The 7-meter one-foot jump test

Balance is a fundamental aspect of physical fitness, especially in activities that involve dynamic movements and sports participation. The 7-meter one-foot jump test challenges a child’s balance and stability, as they must land and stabilize on one foot after the jump. This aspect of the test provides valuable information about a child’s ability to maintain equilibrium and control over their body, which is essential for various physical activities and daily life [26].

The 7-meter one-foot jump test offers objective and measurable results, making it an excellent tool for monitoring a child’s physical fitness progress over time. By recording the distance covered in each jump, educators and healthcare professionals can track improvements and set achievable fitness goals for children. This objectivity motivates children to work toward bettering their performance and maintaining an active lifestyle. The 7-meter one-foot jump test requires a child to jump as far as possible using only one foot, aiming to cover a distance of 7 meters (approximately 23 feet) as quickly as they can. This test focuses on assessing the child’s explosive power and balance, as they must generate force with one leg while maintaining stability and coordination during the jump [26].

Cut off value for Jumping a distance of 7 m on 1 foot as fast as possible (s) test, result: 3.19 SD 0.37.

3.4 The tennis ball throw test

Upper body strength plays a crucial role in a child’s physical development, influencing their performance in everyday tasks and athletic endeavors. The Tennis Ball Throw Test directly assesses a child’s upper body strength and power, providing valuable information about their potential for engaging in sports and physical activities that require strength and agility [27].

Hand-eye coordination is a fundamental motor skill that impacts a child’s ability to perform precise movements. The Tennis Ball Throw Test challenges a child’s hand-eye coordination as they aim and release the tennis ball. Regular practice of this test can help enhance their coordination, benefiting them in various sports and activities throughout their lives [27].

The Tennis Ball Throw Test is a functional assessment that simulates real-life movements and sports-related skills. The child stands in a designated area, grasping a tennis ball with one hand, and attempts to throw it as far as they can. This test evaluates upper body strength, coordination, and the ability to generate force, mirroring activities like throwing, passing, and participating in various sports. The Tennis Ball Throw Test engages children in a fun and competitive activity, motivating them to participate actively in fitness assessments. The excitement of trying to throw the ball as far as possible fosters a positive attitude toward physical activity, promoting a sense of enjoyment and accomplishment in the process [27].

Cut off value for Throwing a tennis ball with one hand as far as possible (m) test, result: 11.97 SD 3.56.

3.5 The medicine ball push test

Pushing the Medicine ball requires coordination and body awareness, as the child must coordinate both hands and exert force uniformly to propel the ball forward. Regular practice of this test can enhance a child’s coordination and spatial awareness, contributing to improved motor skills that benefit them in various athletic pursuits [28].

The Medicine Ball Push Test engages children in an enjoyable and interactive activity, motivating them to actively participate in fitness assessments. The challenge of pushing the ball as far as possible fosters a positive attitude toward physical activity, encouraging children to view fitness as a rewarding and enjoyable endeavor. Objective results in the Medicine Ball Push Test enable children to set and achieve fitness goals. As they record their progress over time, they are inspired to surpass their previous distances, instilling a sense of accomplishment and self-confidence. This process encourages children to take ownership of their physical fitness journey and strive for continuous improvement. The Medicine Ball Push Test is a functional evaluation that mimics real-life movements and sports-related actions. In this assessment, the child stands in a designated area and uses both hands to push a 1 kg medical ball as far as they can. This test assesses functional strength and coordination, resembling actions such as pushing heavy objects and engaging in sports that involve upper body strength [28].

Cut off value for pushing a medicine ball (1 kg) with two hands as far as possible (m) test, result: 3.34 SD 0.47.

3.6 Climbing up wall bars

Climbing up wall bars requires significant upper-body strength and endurance. As children pull their bodies upwards using their arms, shoulders, and core muscles, this test serves as an excellent indicator of their upper body strength and the ability to sustain efforts during physical activity. Wall bar climbing promotes the development of motor skills and coordination. The activity demands precise movements and coordination between the upper and lower body. Regular practice can improve a child’s ability to coordinate their movements, positively impacting their overall motor skills and body awareness [29].

Climbing wall bars demands a combination of agility and flexibility as children navigate their way through the bars. The activity involves bending, twisting, and adjusting body positions to reach higher levels. This agile movement fosters flexibility and adaptability, valuable skills for various physical activities and sports. Climbing up wall bars is a comprehensive fitness assessment that engages various muscle groups and motor skills. In this test, the child ascends a series of vertical bars arranged on a wall, aiming to reach the top as quickly as possible. This activity evaluates upper body strength, grip strength, coordination, balance, and agility, making it a well-rounded measure of physical fitness [29].

The height of each column in the wall bars measures 2.55 meters, and the width is 0.75 meters [29]. Cut off value for Climbing up wall bars as fast as possible (s) test, result: 12.10 SD 2.83.

3.7 The shuttle run test

The Shuttle Run Test, also known as the 20-meter shuttle run or the beep test, involves a child running back and forth between two markers placed 20 meters apart. The child must touch the marker at each end before returning, in sync with audio cues. As the test progresses, the time between the beeps decreases, demanding increased speed and agility. The test continues until the child can no longer keep up with the pace or voluntarily stops. The Shuttle Run Test provides a direct measure of a child’s speed and agility. The quick changes in direction, accelerations, and decelerations required during the test challenge a child’s ability to move efficiently and responsively [30].

This evaluation is crucial for determining a child’s athletic potential and identifying areas for improvement. In addition to speed and agility, the Shuttle Run Test assesses a child’s cardiovascular endurance. The test is designed to increase gradually in intensity, pushing the child’s heart and lungs to work harder as they continue running. A child’s ability to sustain the test for longer indicates a higher level of cardiovascular fitness. The Shuttle Run Test provides objective and quantifiable results, making it an excellent tool for measuring a child’s physical fitness. The total number of completed shuttles is recorded, and this data can be compared to established fitness norms to evaluate a child’s fitness level in comparison to their peers [30].

Cut off value for Shuttle run as fast as possible (s) test, result: 25.87 SD 2.03.

3.8 The 20-meter sprint test

The 20-meter sprint test requires a child to run a straight line, covering a distance of 20 meters as fast as they can. The test assesses a child’s speed and acceleration, making it an efficient evaluation of their anaerobic power and agility. Speed and acceleration are critical components of physical fitness, especially in activities that require quick bursts of energy, such as sports and daily life [31].

The 20-meter sprint test provides a direct measure of a child’s ability to accelerate and attain maximum speed in a short distance. The 20-meter sprint test primarily relies on the anaerobic energy system, which supplies energy for short and intense bursts of activity. By pushing the body to its limits within a brief period, the test evaluates a child’s anaerobic capacity, which is vital for various sports and high-intensity physical activities. The 20-meter sprint test yields objective and immediate results. The time taken to complete the sprint is recorded, providing quantifiable data that can be easily compared and tracked over time. This objectivity allows educators, coaches, and healthcare professionals to assess a child’s progress and tailor fitness programs accordingly [31].

Cut off value for Running 20 m as fast as possible (s) test, result: 4.62 SD 0.40.

3.9 The reduced cooper test

The Reduced Cooper Test is an adaptation of the classic 12-minute Cooper Test, designed to better suit children and individuals with varying fitness levels. In this test, the child runs or walks for 6 minutes, covering as much distance as possible within the given time frame. The distance covered serves as an indicator of the child’s cardiovascular endurance and overall physical fitness. One of the primary advantages of the Reduced Cooper Test is its versatility. Children have the option to run or walk during the 6-minute duration, allowing them to choose the pace that best suits their fitness level. This inclusivity ensures that children of all abilities can participate comfortably and confidently in the assessment [32].

The Reduced Cooper Test primarily evaluates cardiovascular endurance, a critical aspect of physical fitness that indicates the efficiency of the heart and lungs in supplying oxygen to the working muscles. By encouraging continuous movement for 6 minutes, this test challenges a child’s aerobic capacity and stamina. The Reduced Cooper Test provides objective and quantifiable results. The distance covered by the child within the 6-minute timeframe is recorded, enabling educators, coaches, and healthcare professionals to compare and track progress over time. This objectivity facilitates personalized fitness planning and monitoring [32].

Cut off value for Reduced Cooper Test (6 minutes), both running or walking are allowed (m) test, result: 984.82 SD 133.47.

4. Misconception about resistance training in children

Physical activity (PA) does not only involve aerobic activities. Often, sports and even children’s games involve activities of resistance training (RT). In fact, to improve performance, speed, strength, and agility, engaging in resistance training activities is necessary. However, there are often misconceptions, misunderstandings, and myths surrounding RT in children, which may cause confusion and fear [29].

Resistance training (RT), or sometimes referred to as strength training, is a component of sports designed to increase muscle strength, muscular power, and muscle endurance. RT can take various forms, ranging from bodyweight exercises to the use of equipment, which can be manual or robotic. When discussing RT, it is not limited to exercises using equipment only. In children’s RT exercises, strength-building often involves movements such as frog jumps, bear crawls, crab walks, kangaroo hops, and one-leg hops [33]. Children as young as 5 years old can perform single-leg jumps (Table 3) [34].

Misconception	Evidence
Before reaching puberty, a child is incapable of experiencing strength gains.	Before reaching puberty, children have the capability to build strength through improved neurological recruitment of muscle fibers. Moreover, if resistance training programs are closely supervised and prioritize correct technique, children can achieve strength gains with minimal risk of injury.
Engaging in resistance training might lead young boys and girls to become “muscle bound.”	Strength gains in prepubertal individuals are achieved through neurological mechanisms, while during puberty, these gains may be further boosted by muscle hypertrophy facilitated by the presence of pubertal hormones.
Youth participating in resistance training may experience a reduction in their aerobic performance.	Studies have demonstrated that incorporating both aerobic and resistance training in programs can lead to enhancements in aerobic performance. Moreover, it has been observed that combining these two types of training does not hinder strength gains in children.
Resistance training has been associated with concerns about potentially hindering growth in children.	There is no evidence to suggest that properly structured resistance training programs have adverse effects on the growth plates, linear growth, or cardiovascular health of young individuals.
The strength of children today exceeds previous levels.	Addressing strength deficiencies and developing strength reserves is crucial due to the decreasing levels of muscular fitness observed in today’s youth.
1 RM testing is considered risky for young individuals.	When conducted under qualified supervision and adhering to appropriate testing guidelines, 1 RM testing can be a secure approach to assessing muscular strength in youth.

Table 3.

Misconception and evidence about resistance training in children [29, 33, 34].

Resistance training, when appropriately designed and supervised, offers numerous health benefits for children. First, it helps in developing muscular strength and endurance. As children engage in resistance exercises, their muscles adapt and grow stronger, allowing them to perform daily activities with greater ease and efficiency. Second, resistance training contributes to improved bone health. The stresses placed on bones during resistance exercises stimulate bone growth and density, reducing the risk of osteoporosis and fractures later in life. This is especially significant during childhood and adolescence, when bone development is at its peak. Moreover, resistance training positively impacts body composition. It helps to decrease body fat and increase lean muscle mass, fostering a healthier body composition, which can contribute to better overall health and reduce the risk of obesity-related issues. Additionally, resistance training has been shown to enhance motor skills and functional abilities in children. By developing muscular strength, balance, and coordination, children can improve their athletic performance, excel in sports, and develop better physical competence in daily activities [35].

Resistance training also promotes positive psychological effects in children. It can boost self-esteem and self-confidence as they achieve strength and fitness goals. Additionally, it may help reduce anxiety and stress, leading to improved mental well-being. It is essential to note that resistance training programs for children should be tailored to their age, developmental stage, and individual capabilities. Proper supervision and coaching by qualified professionals are crucial to ensure safety and maximize the health benefits of resistance training while avoiding potential risks. With the right approach, resistance training can be a valuable component of a child’s overall physical development and long-term health [35].

The mechanism of strength increase caused by fitness in children is a complex interplay of various physiological processes. When children engage in fitness activities, such as resistance training, several key mechanisms come into play to facilitate strength gains. First, resistance training leads to neurological adaptations. As children perform exercises against resistance, their nervous system learns to recruit more muscle fibers simultaneously, which enhances the force production capacity of the muscles. This improved neuromuscular coordination allows children to exert more strength and power during subsequent training sessions and everyday activities. Second, resistance training stimulates muscle hypertrophy. The repetitive stress placed on muscles during resistance exercises triggers cellular responses that lead to the growth and enlargement of muscle fibers. This muscle hypertrophy contributes to increased muscle strength and endurance, as well as overall improvements in muscular fitness. Third, fitness activities promote bone remodeling and density. The mechanical loading experienced during resistance training encourages bone cells to adapt and remodel, resulting in stronger and denser bones. This is particularly crucial during childhood and adolescence, when bone growth is at its peak, as it helps in building a strong skeletal foundation for the future. Moreover, fitness activities have a positive impact on connective tissues. Tendons and ligaments adapt to the increased loading from resistance exercises, becoming more resilient and better able to withstand forces. Strengthened connective tissues provide stability and support to the muscles, reducing the risk of injuries and allowing children to perform exercises with improved efficiency. Lastly, fitness activities can influence hormonal responses [32].

Resistance training, in particular, stimulates the release of hormones such as growth hormone and testosterone, which play essential roles in muscle growth and development. These hormonal responses contribute to the overall process of strength increase in children. Overall, the mechanism of strength increase caused by fitness in children involves a combination of neurological adaptations, muscle hypertrophy, bone remodeling, enhanced connective tissues, and hormonal responses. By understanding these mechanisms, coaches, parents, and healthcare professionals can design appropriate and effective fitness programs to optimize strength gains and promote the overall well-being of children [32].

Resistance training in children, while generally safe and beneficial, does come with some potential risks that need to be carefully considered and managed. First, the risk of injury is a primary concern. Children’s growing bodies may be more susceptible to overuse injuries or strain if proper technique and supervision are not emphasized during resistance training sessions. It is crucial for coaches, parents, and trainers to ensure that exercises are age-appropriate and that children are using the correct form to minimize the risk of injury. Second, there is a concern about excessive training volume and intensity. Pushing children to lift excessively heavy weights or perform intense resistance exercises beyond their capabilities may lead to physical and emotional burnout. Overtraining can negatively impact growth and development, as well as decrease motivation and interest in physical activity. Another risk is the potential for early specialization and sport-specific training. While resistance training can enhance athletic performance, focusing too much on specific sports or movements at a young age may limit a child’s overall physical development and increase the risk of overuse injuries. Additionally, if resistance training programs are not appropriately designed or supervised, children may be at risk of experiencing emotional or psychological stress related to body image or performance pressure. Ensuring a positive and supportive environment during training is essential to promote a healthy relationship with exercise and physical fitness. Furthermore, resistance training in children with certain medical conditions or physical limitations should be approached with caution [36].

Proper medical evaluation and clearance should be obtained before initiating any resistance training program for children with pre-existing health conditions. To mitigate these risks, it is vital to implement evidence-based and age-appropriate resistance training programs for children. Qualified trainers and coaches who have expertise in working with young individuals should oversee the training sessions. Moreover, creating a well-rounded and balanced fitness regimen that includes a variety of activities, sports, and exercises can promote overall physical development and reduce the risk of overuse injuries. By addressing these potential risks proactively, resistance training can be a safe and effective way to promote the health and well-being of children [36].

5. Physical activity modification

There are several congenital diseases that often occur in children. Congenital heart disease (CHD) affects nearly 1% of births [37]. Indonesia records that 8 out of 1000 births experience congenital heart disease [38], Singapore 9.7 out of 1000 live births [39], and India records 13.3 out of 1000 live births [40]. With technological and scientific advancements, 90% of children with CHD who undergo surgical procedures will survive and are also likely to grow into adulthood [41]. On the other hand, many of these surviving patients will also be exposed to several complications. Data from developed countries indicate that many child patients with CHD and even adults with heart disease have obesity as a comorbidity. This obesity is thought to occur due to a sedentary lifestyle. This often happens because of activity restrictions imposed by parents and even doctors who have a limited understanding of exercise for children with CHD [42].

Currently, there is a lot of research data indicating that physical activity can benefit some CHD patients. Several studies also state that many deaths in CHD patients occur during rest. Many data also prove that structured and measured physical activity, even directed sports, will provide benefits in creating good health, endurance, strength, flexibility, and metabolism. This condition will likely reduce the frequency of relapses, hospitalizations, and even deaths [43].

Caution should still be exercised for pediatric CHD patients. International guidelines on Physical Activity (PA) in CHD focus on guidelines for patients who have undergone surgery, enabling them to engage in physical activity and even competitive sports. Before initiating PA or sports activities, several functional tests need to be considered and conducted. Simple tests that can be performed even at the community level include the 6-minute walk test. This test is performed on flat terrain. It is better to have a 30-meter track for back-and-forth walking for 6 minutes. During the test, patients should be monitored for heart rate, oxygen saturation, dyspnea, and fatigue. This test has been proven safe for patients with cardiorespiratory disorders. This test can at least be conducted for patients with moderate to severe abnormalities. As a reference, the 6MWT result for healthy boys aged 11 to 14 is 576 ± 93 m, and for girls is 545 ± 92 m [44]. Stress Test: This test is often performed using the Modified Bruce Protocol on a treadmill. A good exercise value is above 10 METs. Caution should be exercised when conducting this test in children with pulmonary hypertension, cardiomyopathy with heart failure, arrhythmia, severe outflow obstruction, prolonged QTc, and severe aortic dilation [45].

Atrial septal defect (ASD): Patients without ASD surgery, whether small, moderate, or large, without pulmonary artery hypertension (PAH), are allowed to participate in all sports. If ASD surgery is performed during childhood, physical activity can be resumed 3–6 months after surgery. Direct contact sports are not recommended until after 6 months. If surgery is performed after the age of 40, only low-intensity physical activity is allowed, especially if there are residual PAH, arrhythmias, and ventricular dysfunction [46].

Ventricular septal defect (VSD): Prudent discretion is advised, as individuals afflicted with Eisenmenger syndrome are susceptible to the potential occurrence of unforeseen mortality [47]. Patients who have not undergone surgical intervention, possess minor to moderate ventricular septal defects (VSD), and exhibit unimpaired cardiac function should be granted the opportunity to engage in a comprehensive spectrum of athletic activities. Nonetheless, in cases where pulmonary hypertension and a left-to-right shunt are present, it is judicious to restrict athletic involvement to pursuits of low intensity. Competitive sports are also not allowed. Patients who have undergone VSD closure surgery require 3–6 months of recovery and rehabilitation before participating in all areas of physical activity. However, if patients still have arrhythmias, pulmonary hypertension, and severe heart function decline, their activity should be limited to low-dynamic sport leisure level [46].

Tetralogy of fallot (TOF): Rationally, TOF, which involves various anatomical heart abnormalities and cyanotic conditions, is associated with exercise intolerance. This is confirmed by cardiopulmonary exercise test (CPET) examinations showing significant desaturation. Therefore, regardless of the TOF condition, low-intensity physical activity is allowed [47].

Attention-deficit/hyperactivity disorder (ADHD) is one of the most prevalent neurodevelopmental disorders in childhood, presenting with symptoms of hyperactivity, impulsivity, and/or inattention. The estimated prevalence of ADHD was 5.29% (95% confidence interval [CI]: 5.01–5.56) in community samples of children and adolescents from 35 countries across six continents worldwide. Difficulty in managing children with ADHD arises because they struggle to interact with their environment. Children with ADHD live in their own world. The American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders—5th Ed (DSM-5) divides ADHD into three subtypes based on dominant symptoms: Inattention (ADHD-I), hyperactive and impulsive (ADHD-HI), and combined (ADHD-C) [48].

In a study by Luciano Acordi and colleagues, intriguing findings are reported regarding the benefits of swimming therapy for the mental health, cognition, and motor coordination of schoolchildren diagnosed with ADHD. This training spanned 8 weeks and significantly altered depression and improved cognitive abilities and attention. In terms of motor coordination and physical fitness, the aquatic program yielded satisfying results for the coordination of both limbs, flexibility, and abdominal muscle strength [49].

This research is grounded in reports about the side effects of medications for children and adolescents with ADHD. Around 20% of teenagers experience and report side effects from the medications they consume for ADHD, including mood disorders like anxiety, stress, and depression [50].

One potential explanation for the current findings is that exercise promotes neuroplasticity and neuroprotection, leading to improved cognitive function and increased gray matter volume. Another explanation, proposed by Dietrich and Audiffren, is that exercise engages arousal mechanisms involving neurotransmitter systems, aiding implicit cognitive and emotional information processing in the reticular activating system. In terms of motor coordination, physical training can alter brain functioning and enhance motor coordination [51].

The aquatic program took place in a semi-Olympic thermal swimming pool over 8 weeks, with two sessions per week, totaling 16 sessions. Each session lasted 45 minutes and included approximately 5 minutes of stretching, 25 minutes of swimming instruction, 10 minutes of recreational activity, and 5 minutes of calmness and stretching [49]. Unfortunately, the journal does not elaborate on the teaching experience, how to engage children with ADHD, or how to enhance their focus and concentration.

Parents and teachers often have misconceptions about physical activities or play before starting school lessons. They might view physical activities as energy-draining and detrimental to learning. However, research by Hermoso and colleagues surprisingly reveals that physical play has a positive impact. An intervention involving physical activities was conducted daily before the first lesson (8,00–8,30 am) for 8 weeks. Pre and postassessments were carried out, and the results showed no significant changes in attention and concentration among the students. This indicates that their attention and concentration remained sufficient for learning after physical play and before the study began. However, significant improvements were observed in language and math scores after the active play program. Positive changes were also noted in their physical condition, including fat mass, fat-free mass, muscle strength, and cardiorespiratory fitness [52].