There has been an increasing number of children and adolescents that are involving in resistance training for anaerobic power in schools, fitness centers, and sports training facilities. In addition to increasing muscular strength and power, regular exercise activity in pediatric resistance training may be beneficial. It can influence on ones’ body composition, bone health, and reduce the risk of sport-related injuries. Resistance training is targeted to improve low fitness levels and poor trunk strength as well as improve health and fitness benefits to young athletes. Pediatric resistance training programs need to be well-designed and supervised by qualified professionals who understand the physical and psychosocial uniqueness of children and adolescents. The different training methods along with the progression of the program over time should be challenging and enjoyable for the children.
Anaerobic power is energy that is stored in muscles in the form of adenosine triphosphate (ATP), and can be accessed without the use of oxygen. There are two systems that conduct this type of power which are the phosphagen system and the lactic acid system. People use this form of energy in short bursts that cannot be sustained for no longer than about two minutes. The first stage of the anaerobic power is adenosine triphosphate phospho-creatine (ATP-PC), which only supplies energy for about one to six seconds, after that the phosphagen system takes place, and then the lactic acid system or glycolytic system, which begins by producing energy by breaking down carbohydrates. While these systems are running, the body is using more energy than it can replenish, which may lead to cramping, fatigue, and lactic acid buildup quickly. Individuals should train to improve their anaerobic power by building their capacity to use power systems that do not require oxygen.
Measuring Anaerobic Power
For adolescence, anaerobic capacity can be measured by using the Wingate test. In this test, a person pedals a mechanically braked bicycle for thirty seconds as fast as possible, and a flywheel is used to count revolutions. Testing an individual’s capacity frequently ensures that his or her workout routines are improving their abilities. Direct measurements of the rate or capacity of anaerobic pathways for energy turnover presents several ethical and methodological difficulties. Therefore, rather than measuring energy supply, pediatric exercise scientists have concentrated on measuring short-term power output by means of standardized protocol tests such as short-term cycling power tests, running tests, or vertical jump tests. However, it is possible to measure by finding the levels of lactate on the pre-test and post-test phases as well as the individuals vital capacity. “The level of lactate in blood (mmol per liter) is measured in accordance with a protocol that considers the analysis of a 3mL sample of blood, using the calorimetric method and a lactate analyzer photometer” (1). Vital capacity can be measured using a spirometer to measure the maximum amount of “air that can be forcedly breath from the lungs after a maximum inspiration” (1).
As for children, “findings have been reported by measuring mechanical force or power output files during sustained isometric maximal contractions or repeated bouts of high-intensity dynamic exercises” (2). There is no perfect test, but it is important to acknowledge the benefits and limitations of each testing or training method. However, “metabolic adaptations during exercise in children and adolescents have been rarely investigated using muscle biopsies, radioactive materials or arterial catheters. This is due to the invasiveness of these techniques. Ethically for children, measurements have to be relatively non-invasive, and certainly must carry minimal or no risk to health” (2).
Resistant training can offer many benefits for children and adolescents when it is properly prescribed and monitored. The potential benefits would be an “increase in muscle strength, muscle power, local muscle endurance, enhanced motor skill and sports performance”; also an improvement in “bone mineral density, body composition, insulin sensitivity, and blood lipid profile” as well as a “reduced risk of sport-related injuries” (3). Also, research concludes that caffeine seems to be ergogenic during high-intensity exercises and has effect on resistance training. “High-intensity exercise seems to be favorable affected (i.e. sprinting, sprint cycling power) with methodologies employing protocols that mimic sport activities (i.e. 4-6 seconds)” (4). Caffeine seems to be beneficial for athletes in sports such as “soccer, rugby, lacrosse, and football” (4).
Limitations of Anaerobic Power
There are limitations when training for anaerobic power. During childhood, children have an immature musculoskeletal system, which is structurally different than the mature system. When measuring, testing, or training for anaerobic power, it is important to recognize the limitations of the immature musculoskeletal system when designing training programs by modifying rules for sports and evaluating acute and sub acute injuries. The reason being of limitations is because of the high risks of children injuring themselves by overdoing their muscles during heavy weight training.
Risks and Concerns
Since anaerobic power involves explosive movements, there are some risks and concerns that one must take into consideration. Macrotrauma is a fast and sudden injury caused by a major force of action. For example, the injury could be due to a fall or hit during physical activity. Macrotrauma can cause injuries such as fractures, sprains of ligaments, muscle strains, and bruises. Also, there are risks of microtrauma, which is due to a repetitive injury over a long period of time. Types of injuries include stress fractures and many other syndromes. Macrotrauma can occur when performing in organized sports or during free play, and prevention of injuries requires adequate supervision, appropriate matching of competitors, and modification of rules as well. Also, there are concerns about youth resistant training due to the fact that there is potential injury to the “physis or growth plate in a young lifters body” (3). However, the risk levels for adolescents is slightly smaller, which is why they are able to compete effectively and safely in anaerobic events and competition with supervision and guidance that is responsive to their unique musculoskeletal. Guidelines for pediatric resistant training should be followed for the safety of the children from serious injuries.
Training for Anaerobic Power
For children, it is suggested that kids should not put a lot of stress or over stress their bodies when it comes to weight training. Specialists believe that sports such as track and field (throw and jump events), basketball and volleyball (vertical jump) include anaerobic power for kids when power training. As for adolescence, they are able to do a more concentrated and modified training for anaerobic power such as plyometrics, ballistics, explosive strength training, and heavy strength training. Although there is no minimum age requirement at which children can start to resistant train, all participants must be “mentally and physically ready to comply with coaching instructions and undergo the stress of a training program” and “if a child is ready for participation in sport activities (generally age 7 or 8), then he or she is ready for some type of resistant training” (3). When designing resistant training programs for young athletes, the “acute program design variables that should be considered when designing pediatric resistant training programs include 1) warm-up and cool-down, 2) selection and order of exercise, 3) training intensity and volume, 4) rest intervals between sets and exercises, and 5) repetition velocity” (3). The warm-up and cool-down is designed to “evaluate core body temperature, enhance motor unit excitability, improve kinesthetic awareness, and maximize active ranges of motion” (3). In selection and order of exercise, the individual must start with simple exercises and gradually progress to more advanced workouts. Training intensity and volume is referred to as the amount of resistance used and total amount worked during a training session. As for rest intervals between sets and exercises, 2-3 minutes are recommended for adult lifters. However, children and adolescents can resist fatigue to a greater extent, which gives them a 1 minute rest interval when performing a moderate-intensity resistance exercise activity. In repetition velocity, “as youth increase movement velocity during training, it is critical that technical performance of each exercise is mastered before progressing to more advanced movements” (3).
Child and Adult Differences
According to research, it is said that “children are able to resist fatigue better than adults during one or several repeated high-intensity exercise bouts” (2). During growth and development, mass-related short-term power output increases dramatically, and the increase in peak blood lactate becomes lower. “Adults who complete strenuous exercise are usually exhausted and need several hours to recover from their effort. In contrast, children often request to repeat high-intensity exercises 15-30 minutes after their completion because they think that they could improve their previous performance” (2). This shows that the observed difference between children, adolescents, and adults during short-term power output testing may be due to neuromuscular and hormonal factors as well as improved motor coordination.
Anaerobic fitness is used every day during the pediatric stages of life and has been given the impression that it has the “potential to offer observable health and fitness value to children and adolescents” (3). During physical activity or sport, it is known that the child is more attracted to short-burst or fast-like movements than to long-term activities. Also, it is well known that in anaerobic activities such as sprint cycling, sprint running or sprint swimming, the child’s performance is poorer than the adult. This is partly due to the child’s slower ability to generate mechanical energy from chemical energy sources during short-term high-intensity work or exercise. There are many studies that people believe how anaerobic power plays a huge role and how anaerobic activity works as well as why people need it.
Also, it is known that increasing your anaerobic capacity can give you significant improvements in the efficiency of your aerobic system. Information shows that as children start to transition into adolescence and into adulthood, their recovery time increases, they are able to tolerate a lot more stress, and be more efficient anaerobically making them able to last longer while doing an intense activity.
Overuse injuries due to repetitive microtrauma represents a new spectrum of injury that has arisen with the rise in organized sport for adolescents. Injury prevention for overuse injuries requires recognition of the risk factors for injury, and an appropriate modification and diversification of training regimens, an optimization of mechanics with technique and equipment, and adequate conditioning.