ACSM'S Health & Fitness Journal:
KID STUFF: Effective Strategies for Developing Young Athletes
Faigenbaum, Avery D. Ed.D., CSCS, FACSM; Myer, Gregory D. Ph.D., CSCS, FACSM
Avery Faigenbaum, Ed.D., CSCS, FACSM, is a full professor in the Department of Health and Exercise Science at The College of New Jersey, where his research focuses on the role that resistance exercise plays in the health and fitness of children and adolescents.
Greg Myer, Ph.D., CSCS, FACSM, is codirector of research for the Division of Sports Medicine at Cincinnati Children’s Hospital Medical Center and holds primary academic appointments in the Departments of Pediatrics and Orthopaedic Surgery within the College of Medicine at the University of Cincinnati.
The authors declare no conflicts of interest and do not have any financial disclosures.
Disclosure: The authors declare no conflicts of interest and do not have any financial disclosures.
LEARNING OBJECTIVES: • To be aware of the latest trends in physical activity and fitness conditioning for school-aged youth
• To understand the potential benefits and concerns associated with youth strength and conditioning
• To gain knowledge to design resistance training programs that enhance physical fitness and reduce the risk of sport-related injuries in aspiring young athletes
An increasing number of people are exercising in fitness centers, and current reports indicate that club membership has increased to 50.2 million members (21). In addition to specific fitness programs for older adults and corporate executives, youth programming is becoming one of the fastest growing trends in the fitness industry (1,21). Nowadays, health-conscious parents are becoming more aware of the importance of establishing healthy habits at an early age, and a growing body of evidence underscores the significance of planned preparatory training and conditioning for aspiring young athletes (19,33). Qualified fitness professionals who understand the fundamental principles of pediatric exercise science are in a desirable position to help children and adolescents gain the skills, strength, and confidence they need for a lifetime of physical activity and sport.
Although millions of school-aged youth participate in recreational and interscholastic athletics, participation in organized sports does not ensure that the youth meet the minimal physical activity guidelines for moderate-to-vigorous physical activity (MVPA) (22,38). Moreover, sport participation without preparatory conditioning increases the risk of sport-related injuries in athletes whose musculoskeletal system is ill prepared for the demands of sport practice and competition (20,32). Although children ordinarily develop movement patterns by 6 or 7 years of age (27), fundamental motor skills, such as throwing, jumping, and balancing, should be refined by regular participation in youth programs that are purposely designed to enhance muscular strength and motor coordination (13,23). Indeed, current public health recommendations for youth 5 to 17 years old now encourage participation in planned exercise activities that include those that strengthen muscle and bone (43). This article highlights the latest evidence on the importance of enhancing muscle strength and skill-related fitness in youth and describes program design considerations for developing training programs for aspiring young athletes. For the purpose of this article, the terms youth and young are broadly defined to include both children and adolescents.
SECULAR TRENDS IN YOUTH PHYSICAL ACTIVITY
The World Health Organization now recognizes insufficient physical activity as the fourth leading risk factor for global mortality for noncommunicable diseases after high blood pressure, tobacco use, and high blood glucose (43). Epidemiological evidence indicates that contemporary youth are not as active as they used to be, and the decline in regular physical activity is observable by age 6 years (6,40). At present, self-report data suggest that only 12% of high school students in the United States meet the Healthy People 2020 objective for both aerobic and muscle-strengthening activities (17). Inadequate levels of physical activity adversely affect the health of young people and sedentary behaviors established during the growing years appear to form the foundation for such behaviors in the future (3).
A contemporary corollary of physical inactivity among school-aged youth is a deleterious decline in children’s muscular strength and motor skill performance. Pediatric researchers have reported secular declines in selected measures of muscular fitness, including sit-ups, bent-arm hang, leg lifts, standing broad jump, and shuttle run speed (8,28,37). These observations are significant because youth with low levels of muscle strength and poor motor skills may be more prone to have sport-related injuries and less likely to engage in physical activity later in life (2,24,31). In one longitudinal study that examined the determinants of physical activity in the youth, motor proficiency was a significant predictor of physical activity in children 6 to 10 years of age (24). That is, children with high levels of motor coordination at age 6 years showed negligible changes in physical activity during the next 3 years compared with children with lower and moderate levels of motor coordination. Because muscular strength is an essential component of motor skill performance in children (27), there is a pressing need to enhance the muscular fitness and motor coordination of school-aged youth with age-appropriate interventions. In our view, participation in FUNdamental fitness activities that integrate strength-building exercises with skill-enhancing movements drives participation in MVPA and sport play (i.e., practice and competition), which, in turn, sets the stage for participation in a variety of wellness-enhancing physical activities later in life (10,32) (Figure 1).
Youth who do not enhance their muscular strength and motor skill development early in life may not be able to break through a hypothetical “proficiency barrier” later in life that would allow them to participate in recreational activities and competitive sports with energy, vigor, and confidence (39). Of note, overweight and obese children of both sexes tend to have even low scores of motor coordination compared with normal-weight children during this critical period of life (25). These observations highlight the inverse relationship between body mass index and motor performance in the youth and underscore the importance of promoting regular participation in strength-building and skill-enhancing activities early in life before the youth become resistant to our health-enhancing recommendations. The International Olympic Committee recognizes the importance of physical activity and sports for the youth and promotes the early identification of individual deficits in physical fitness in aspiring young athletes and the prescription of exercise training programs specifically designed to address individual limitations (29).
EXERCISE IS SPORTS MEDICINE
Current guidelines state that children and adolescents should accumulate at least 60 minutes of MVPA daily in the context of family, school, and community activities (43). Regular physical activity during the growing years is a powerful marker of health and is associated with favorable changes in body composition, cardiovascular risk factors, metabolic health, muscular strength, bone density, and symptoms of anxiety and depression (36,43). In addition, a growing body of evidence indicates that multifaceted training programs that enrich the learning environment and target fitness deficits may help young athletes achieve a level of neuromuscular performance that may reduce their risk of sport-related injuries (19,32).
Youth who are not exposed to enriched environments in which they can participate in a variety of activities that enhance muscle strength and movement skills may be at an increased risk for negative health outcomes later in life. This view is supported by the work of Haga (18) who found that children with a low motor competence performed more poorly than children with a high motor competence on nine different measures of physical fitness (e.g., standing broad jump, throwing a tennis ball, climbing wall bars, and shuttle sprint) during a period of 32 months. Other researchers have shown that muscular strength is an effective modifier for the association between aerobic fitness and risk of fractures with the greatest risk of fracture seen in those with the lowest levels of muscular strength (7). Fitness professionals should be aware of these observations as well as the likelihood that motor deficiencies that are not identified and treated early in life may persist into adolescence and adulthood.
Unlike hypertension or dyslipidemia, there may not be any clinical markers or laboratory tests that can identify inactive youth nor are there any medications that can treat deficiencies in movement skill or physical activity. Consequently, inactive youth who want to participate in a competitive sport program should be identified early, and qualified professionals need to prescribe developmentally appropriate and enjoyable activities that are consistent with individual needs, goals, and abilities. Exercise deficit disorder or EDD is a term used to describe a condition in youth characterized by reduced levels of physical activity that are inconsistent with positive health outcomes (15,16). What has previously been described in a vague manner as “out of shape” should be viewed as a deficit characterized by reduced levels of physical conditioning that are inconsistent with long-term health and well-being. Fitness professionals need to target movement deficiencies and physical weaknesses so that aspiring young athletes are better prepared for the demands of sports practice and competition.
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Regardless of body size or innate ability, participation in physical activity should not begin with sport practice but should evolve out of preparatory fitness conditioning. From this perspective, a sedentary 10-year-old girl who takes the bus to school, plays video games in her free time, and spends most of her weekends “surfing” the Internet is not prepared for the demands of a competitive soccer program. Young athletes need to begin participation in a multifaceted training program at least 2 months before the start of the sport season. According to the National Athletic Trainers Association, more than half of all pediatric overuse or repetitive trauma injuries may be preventable with simple approaches that include preseason and in-season preventive training programs (41).
RESISTANCE TRAINING FOR YOUNG ATHLETES
Progressive resistance training is the pillar of preparatory conditioning for athletes of any age. By enhancing musculoskeletal strength and physical fitness, conditioned athletes are less prone to injury and more likely to experience success as well as the mere enjoyment of physical activity. A growing number of children and adolescents now resistance train in schools, fitness centers, and sport training facilities, and the qualified acceptance of pediatric resistance training by medical and fitness organizations has become widespread (4,12,30). Scientific evidence and clinical impressions indicate that resistance training can be relatively safe, effective, and enjoyable for children and adolescents provided that qualified supervision is present and established training guidelines are followed (14,42). Of interest to youth fitness professionals is the observation that significant gains in muscular strength without any report of injury have been reported in school-aged youth who participated in supervised weightlifting programs, which included modified cleans, pulls, and presses (12).
Although data from the pediatric literature indicate a relatively low risk of injury in children and adolescents who resistance train in supervised programs (14,26), fitness professionals who prescribe and supervise youth resistance training should be cognizant of the potential for injury and should attempt to reduce the risk of injury with proper instruction and an appropriate progression of training loads in a safe training environment. With guidance from a qualified fitness professional, improper exercise technique and muscle imbalances can be identified and successfully treated. For example, the untrained 8-year-old girl in Figure 2 demonstrates improper exercise technique while performing the squat exercise. After several weeks of training that included supervised instruction and reinforcement of desirable movement patterns to address neuromuscular deficits, she made observable improvements in her exercise performance (Figure 3).
Regardless of the training goals (i.e., health or performance), professionals who work with the youth should be keenly aware of proper resistance training procedures and the technical performance of various exercises to reduce the likelihood of unsafe behaviors and improper training techniques. Of note, in one report of training-related injuries presenting to U.S. emergency rooms, 77% of the reported injuries in the 8- to 13-year-old age group were categorized as accidental and were most often related to “dropping” and “pinching” in the injury descriptions (34). These are important considerations for fitness professionals who design and supervise training programs for children and adolescents. From our experience, young lifters who do not receive instruction on proper exercise technique and appropriate training loads tend to overestimate their physical abilities and spend too much time training the so-called “mirror muscles” (i.e., chest and biceps). Modifiable risk factors associated with youth resistance training injuries that can be reduced or eliminated with qualified supervision and instruction are illustrated in Figure 4.
In general, most 7- and 8-year-old children are ready for some type of resistance exercise provided they are able to follow coaching instructions and undergo the stress of an exercise program. However, regardless of the starting age, all youth should receive instruction on appropriate starting weights, proper spotting, and the proper handling of barbells, dumbbells, and plates. This type of coaching not only enhances participant safety, but direct supervision of youth resistance training programs can improve program adherence and optimize training adaptations (9). Furthermore, there is not one “optimal” combination of sets, repetitions, and exercises that will promote favorable adaptations in all children and adolescents (12). Instead, the sensible integration of different training methods and the periodic manipulation of program variables over time will keep the training stimulus effective, challenging, and pleasurable.
We refer to this concept as integrative neuromuscular training or INT because it incorporates a combination of performance-enhancing and injury-reducing components (e.g., strength, power, and neuromuscular control) into one multifaceted fitness program (32). This type of training does not involve expensive equipment, but it does require qualified instruction and an understanding of pediatric exercise guidelines. For example, findings from a recent analysis of pediatric resistance training research highlight the importance of systematically progressing the training program over time to make persistent gains in muscular fitness (5). These findings are particularly important for young athletes who need to continue resistance training throughout their competitive sport season to maintain training-induced adaptations in muscular fitness. Program variables that should be considered when designing pediatric resistance training programs are outlined in the Table.
TABLE: General Pedia...Image Tools
When prescribing resistance training programs for young athletes, it also is important to consider the total exercise volume that includes sport practice and competition as well as participation in recreational activities, physical education, and possibly private fitness training sessions. Some aspiring young athletes with relatively immature musculoskeletal systems may not be able to tolerate the same exercise dose as their teammates. Because of the interindividual differences in stress tolerance, each participant should be treated as an individual, and fitness professionals must be aware of incipient signs of overtraining. For example, chronic muscle soreness, lack of enthusiasm about training, and personality changes would require a modification of the training program. A reduction in sport performance and an increased risk of injury can result if resistance exercises are simply added onto a young athlete’s daily schedule without any regard for rest, recovery, and rejuvenation, which are essential to optimize performance.
Although all modes of training have their advantages and disadvantages, resistance training with free weights, medicine balls, and one’s own body weight may be particularly beneficial for young athletes who need to enhance strength, power, balance, and motor skill performance as part of an integrated program. Although the isolated effects of core training and balance training have not been demonstrated clearly, the potential benefits of this type of training on school-aged youth can be substantial (35). For example, a young tennis player with a dynamically stable core likely will be better prepared to respond to the high forces generated at the distal body parts during competition. Exercises such as the lunge progression are designed to simultaneously improve muscle strength and core stability during a multiplanar movement progression (Figures 5–9). Once an athlete demonstrates technical proficiency on the front lunge exercise, she has “earned the right” to progress to the walking lunge exercise, which is more challenging.
Although different combinations of sets and repetitions have proven to be effective in younger populations (12), the youth must first demonstrate performance of each exercise with correct technique using a light load and then gradually progress the training intensity and/or volume without compromising exercise technique. In our youth programs, we start with relatively simple movements and progress the program based on technical skill and confidence to perform the desired movement. For example, we recently reported significant gains in selected measures of strength and power in 7-year-old children who performed five strength-building primary exercises and four skill-enhancing secondary exercises during the first 15 minutes of a physical education class (11). Participants in this study received specific feedback of the quality of each movement and were taught the value of initiating exercises from the athletic stance (e.g., eyes level, chest over knees, back slightly arched, knees bent, and feet wider than shoulders). Also, we used the phrase “look like an athlete” to reinforce proper body mechanics and correct errors in movement skill technique.
Fitness professionals who understand the uniqueness of physical and psychosocial characteristics of the youth have the potential to improve the preparedness of aspiring young athletes for sports. Although there are many approaches to enhance the physical fitness of the youth and reduce the likelihood of sport-related injuries in young athletes, regular participation in a variety of strength-building and skill-enhancing activities should form the foundation for future sport participation. Continuing education in the fields of motor development, motor learning, and pediatric exercise science, along with opportunities for fitness professionals to gain practical experience working with children and adolescents, is integral to the development and promotion of developmentally appropriate training programs that encourage lifelong physical activity.
CONDENSED VERSION AND BOTTOM LINE
Concomitant with the increase in organized youth sports is a surge in sport-related injuries in boys and girls who are ill prepared for the demands of sport practice and competition. Qualified fitness professionals are in a desirable position to implement programs designed to enhance the muscle strength and motor skill performance of children and adolescents that will reduce their risk of sport-related injury. Age-appropriate training programs can help boys and girls gain the strength, skills, and confidence needed for successful sport participation.
The authors thank Jim McFarland from Hillsborough High School in New Jersey for his contributions to this article.
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Children; Strength Training; Motor Skills; Preseason Conditioning; Sport Injuries
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