Benefits and Considerations of Resistance Training in Prepubescent Athletes

For years, many have shunned on the fact of subjecting children to resistance training programs. This has mainly been due to fears that have been misconstrued, such as children stunting their growth, muscle tears/strains, etc. However, with proper knowledge of lifting and proper safety techniques, resistance training can be beneficial to children of all ages. According to David Martinez (1997), the literature suggests that a well-designed program can be safely undertaken by prepubescent as well as pubescent athletes (13). The horror stories that many have heard about are very few and far between and have only occurred due to improper safety and lifting considerations such as improper lifting technique and excessive plate loading. With that being said, athletes and recreational enthusiasts of all ages can become subject to unintended accidents. As stated in the Strength and Conditioning Journal by Avery Faigenbaum and Schram (2004), despite the previous contention that resistance training was inappropriate or unsafe for young athletes, the safety and effectiveness of this program are well documented, and the acceptance of youth strength training by medical and fitness organizations has become almost universal (16). The positive effects of resistance training far outweigh the potential risks, and if a proper regimen is followed and done correctly, injuries can become less prevalent in today’s youth athletes.

Resistance Training does not always mean that a child will be put under a barbell in the weight room and asked to do a set of bench press, but rather can do almost anything. Resistance is the force required to move under certain conditions, or the force required to move against an opposing force, whether it be gravity and body weight with pushups, or a 5lb dumbbell pushing down on a lever such as your arm or leg. The term Resistance Training can be very broad and can be incorporated/manipulated to fit the needs of children of all ages. For instance, a five-year-old may be doing body weight squats, while a 10-year-old may be using variable resistance bands, and a 13-year-old may be starting to learn the correct way to incorporate a barbell in a squat. With this paper, information will be provided to help encourage the use of Resistance Training by children of all ages and highlight the advantages of a lifetime of physical fitness. Faigenbaum and Schram (2004) have stated that resistance training can have numerous benefits to all athletes and children. “In addition to enhancing muscular strength, regular participation in a resistance training program has the potential to strengthen bones, facilitate weight control, enhance psychosocial well-being, and improve cardiovascular risk profile” (2).

One of the most common concerns of many adults is that resistance training can stunt bone growth by damaging growth plates and inhibit maturation. According to the NSCA position stand (1996), in some cases damage to this area can cause the ephysis to fuse causing limb deformity and/or the cessation of limb growth (63). There have been cases where children have stunted their growth; however, this was due to improper technique, knowledge and safety concerns, which led to fractures in the epiphyseal plate of long bones. The NSCA (1996) has stated that most of these injuries were due to improper lifting technique, maximal lifts, or lack of qualified adult supervision (63). The epiphyseal plate is the site where growth occurs in the long bones. This site usually stays open until late puberty/early adulthood when limb length ceases and the plate then closes. If this site of the bone is damaged in any way, growth may stop prematurely due to cessation of osteoblastic activity, or bone formation. In some cases the NSCA (1996) has noted that the potential for this type of injury in prepubescents may be less than adolescents because the growth plates may actually be stronger and more resistant to sheering type forces (63).

There is also the argument of at what age shall a child begin a resistance training or fitness regimen. There is no real numerical age limit to when a child can begin resistance training, for the resistance can be as little as air! The governing factor for resistance training in children should not be the chronological age of the child but more the biological/mental age, that is, can the child understand and properly perform the tasks at hand. As stated in the NSCA position statement (1996), if the program is appropriate for the child’s age and maturation, it may foster favorable attitudes towards fitness and lifelong exercise (70). As long as the child is willing to train, has knowledge of why they are performing the tasks as far as how they can improve the athlete’s skill, proper safety precautions, and guidance, they should be able to train at any age. According to the NSCA position statement (1996), if the program is well designed and supervised by qualified adults who appreciate the importance of having fun, resistance training may offer socialization and related benefits that are comparable to those gained from participation in team sports (69).

The child must be focused on the task and willing to complete it. Disgust or lack of interest from the child can lead to carelessness, and in turn possibly cause improper form and technique. With improper form and technique injury or unnecessary stress to joints can become an issue. Once a child is willing to train, maybe because it seems fun, they then must be informed of why they are performing the task and how it can help them. Even if the child does not fully comprehend what is being said they should hear and understand that resistance training will help them improve in their preferred sport. With knowledge of the program can come appreciation; if the child appreciates and understands what they are doing, then attentiveness to exercise and caution can improve. Children will know what should be focused on during an exercise, and the knowledge and visualizing of how it can help them may improve their drive to perform.

It is highly important that the child is medically cleared and is properly supervised and instructed on the lift before any exercise is performed. Martinez (1997) stated in his article that “first a complete physical and accurate medical history must be completed by a physician“ (13). If the child is below average in health and conditioning they should first begin a program to increase their fitness levels to the normal range.  According to Martinez (1997), it should be noted that unconditioned athletes are more prone to injury due to the onset of fatigue(15). Before any lift or exercise is demonstrated and performed the child’s instructor should inform the trainee of what safety equipment should be used for the exercise if any.  The trainee should be aware of how to utilize the safety equipment, such as where to place safety bars for the squat and how to adjust them. The instructor should then properly demonstrate the exercise that is to be performed and provide key words or phrases along with pointers to the trainee. Key words and phrases are important to help correct improper form during a lift without physically intervening. For example, if one is to perform a squat and they are leaning over their toes with a slightly bowed back, you could say “shoulders back, chest high, and stick your butt out;” if the trainee was informed of these key phrases during the demonstration then they will be aware of what to do. After instruction on safety and the demonstration, the child can then attempt the exercise; however, the lift should be completed with little to no weight until it is observed that the child has demonstrated proper form. Once proper form is demonstrated and it seems that the trainee is capable, weight can be added. Martinez (1997) said that “there is no reason for prepubescents to perform fewer than 8 reps per set, since such a regimen implies heavier loads that would only expose them to sub maximal loads that are too close to their maximum capability“ (14). The difference between a one repetition maximum and an eight-repetition maximum in children is not significant due to fiber development and neural recruitment patterns.

There should always be a proper introduction to resistance exercises, stating why they are important and how they can be of benefit to the child. The child must have knowledge of what they are doing before they start. You have already informed the child that participating in this training program will aid their performance in the sport, but how is this done? Each major exercise and its benefits should be explained to the child. The child may not be fully aware of what you are talking about, but you may say “the bench press will help you as an offensive lineman in football by giving you strength to control the defensive linemen”. This is an easy explanation but it will give the child a reason to want to perform and they will be aware of why the exercise is done.

Sports specific resistance training can be incorporated into programs and have been shown to decrease that numbers of injuries that are prevalent in today’s youth sports. According to Faigenbaum and Schram (2004), the incidence of overuse injuries sustained by young athletes could be reduced by 50% if more emphasis was placed on the development of fundamental fitness abilities before sports participation(4).Injury profiles and a needs analysis of a child/sport should be done when planning a training regimen, which includes an observation of energy systems used, injuries prevalent to the sport, muscular demands and movements performed in the sport or activity. By doing this, one can know what type of lifts should be incorporated in a program, and what can be done to strengthen potential weaknesses. Faigenbaum (2004) reported that in a recent study that documented the effectiveness of a resistance training program on female European handball players from 16 to 18 years of age, it was found that “players that did not participate in the conditioning program had a 5.9 times higher risk of injury than players who participated in the training program“(3). Faigenbaum has also noted that a training frequency of 3 days per week for at least 6 weeks seems to be the time that is needed to obtain the positive effects of resistance training (4).

Proper technique should always be emphasized and there should always be proper supervision. Improper form/technique and inadequate supervision is the leading cause of any weight room or resistance training affiliated injury. Improper technique usually occurs because of two reasons: the trainee was never properly shown how to perform the lift and never given key word phrases, or the trainee is using too much weight. If the trainee is not shown the correct way to perform an exercise and what to listen for as far as critique, then bad form usually follows. The lifter should always have a spotter, the spotter can assist if the resistance is beginning to break the lifter’s form and if a spot is not required then the spotter should observe the exercise for correct form. A spotter is highly important to people undergoing resistance training at any age.  However, Martinez (1997) states that in children a spotter is needed for encouragement and safety factors, not to help the individual through positive and negative fatigue when completing a set (14). A spotter should be able to spot and correct form without physically intervening. If a weight is too heavy and fatigue sets in, form is the first thing to deteriorate in an exercise. As muscles fatigue, the body and other muscles try to find a way to move the resistance and complete the lift. This is why you see many people at the gym lift their rear end off the bench press while doing a lift or squirming in a certain way, the body is trying to compensate!

It has been found that resistance training can have a beneficial effect on bone mineral density in prepubescents of both sexes. However, there must be enough stress placed on the bones in order to see a favorable increase in bone mineral density. According to Kraemer and Fleck (2004), the mechanical loading of bone has a threshold that must be met to have a positive effect on factors related to bone health, unfortunately the threshold for training is not known(290). By mechanically loading bone at a younger age the added stress can possibly speed up the time it takes for an individual to reach peak bone mass. Peak bone mass generally occurs between the age of 25-30 years of age and is defined in The Essentials of Strength and Conditioning (2000) as the maximum bone mass achieved during early adulthood when the mechanism of bone growth still function at optimum levels (62). The NSCA position statement (1996) states that although peak bone mass is strongly influenced by genetics, nonhereditary factors such as exercise and proper nutrition can be important estrogenic stimuli (69).

The NSCA position statement (1996) believes that in prepubescents it appears that training induced strength gains are more related to neural mechanisms than hypertrophy factors (66). Therefore, muscular strength in preadolescents is primarily due to neural adaptations, or better neural recruitment and fiber stimulation rather, than hypertrophy or an increase in muscle mass. According to the NSCA position statement (1996) on youth training, without adequate levels of circulating testosterone to stimulate increases in muscle size, prepubescents apparently have more difficulty increasing their muscle mass consequent to a resistance training program (up to 20 weeks) as compared to older populations (66). As the child begins to train the body learns to better recruit muscles and groups of fibers to move a weight. At the beginning of a training program a child may require 100% of their muscle fibers of their bicep brachii to curl a 25lb dumbbell, but 4 weeks later they may only require 65% of the muscle fibers in their bicep to curl the same 25lb dumbbell. These changes in strength are due to neurological adaptations, and not muscle fiber cross sectional growth. At the same time as a resistance training program may be going on, the child may be growing and gaining strength naturally due to their age and onset of puberty. However, strength training is still beneficial; according to the NSCA position stand, several studies have reported significant improvements in strength during prepubescence without corresponding increases in gross limb morphology, when compared to similar control groups (66) The NSCA position stand (1996) states that strength increases were evident even when natural limb growth was statistically handled(66).

It has been found through studies by the NSCA, that children undergoing resistance training can improve motor skills that they are trained for such as sprint and agility speed, vertical jump and long jump. Training adaptations are made based on the external demands of the program and can be manipulated using durations of exercise, intensity, rest, and velocity of movements. These training variables can be used to increase performance in areas that need improvement or that need to be focused on. In the NSCA position statement (1996), improvements in selected motor fitness skills have been observed in children following resistance training programs; several studies have reported increases in the long jump or vertical jump and one study has noted an increase in 30-meter dash time and agility run time (66). The term training specificity is very important when considering training regimens for athletes of all age but it is even more important in children. The body will adapt and change to the stimulus it is subjected to, in other words the adaptations due to exercise are exercise specific, and in order for them to carry onto a playing field the exercises must be sports specific and match the actions of the sport. As stated by the NSCA position stand (1996), the training adaptations in children are rather specific to the movement pattern, velocity of movement, contraction type, and contraction force (66).

Childhood is a time of comparison, when we look at other and ask ourselves “am I that good?” It is controversial, but it is possible that resistance training, or even just a fitness routine, can show increased self-confidence, reliability, and self-esteem. Self-esteem and self-confidence go pretty much hand in hand but can have a huge impact on a child. If a child does not think highly of himself or sees himself as incapable of doing something then they may hold back from many aspects of life. Resistance training may be able to help with these problems by showing the child that they are capable of success.  The NSCA position statement (1996) a study done with untrained adolescent girls has noted improvements in self-efficacy and general self-esteem following a 12-week resistance training program, while on the same note a similar study done for 8 weeks showed no positive results. The findings of the study support the contention that the psychological benefits or resistance training may depend the intensity and duration of training, and may be most apparent in children who begin training with below average measures of strength and psychological well-being (68).  Seeing improvements in strength and even physical appearance can boost a child self-esteem. Hearing positive feedback from his coach or trainer can also boost his confidence and show him that nothing can stand in his way.

Many may not realize that a training regimen also develops discipline, reliability and dedication. All of these can impact task completion in school and at home. A young trainee can learn how to stick to a program and must learn to be dedicated. They will soon find out that with dedication and adherence to a program that good things will follow. A child can develop reliability, because he needs to adhere to his program and always work to achieve what must be done on that day. These little things can translate to school with homework and time management. As noted in the NSCA position stand (1996), parents of prepubescents who perform resistance training have observed that their children are more likely to do their homework and household chores following resistance training (68).

There are many different ways that one can train varying the resistance, force, velocity, and the substance/environment (water, air) that they perform their exercises in. Some of the training modalities are pneumatics, hydraulics, isokinetic, isometric, isotonic, water resistance, bands and free weights.  Each of the modalities can have their own unique benefit and application to training. Pneumatics are not widely used and are more of a new age training system that uses compressed air instead of weights. This is just as effective as free weight systems like the bench press, pec deck machine, etc., except the loading of weight is gone and makes for fast and easy weights changes. Hydraulics are very safe for children seeing that there is no eccentric loading, therefore one cannot be hurt from a weight pushing down upon them. Isokinetic machines are usually used for rehabilitation but can be used in any situation. On an is kinetic machine the velocity of the movement is fixed throughout the range of motion. Isometric strength training is very easy and requires no weight. One who performs isometric contractions either used themselves or a solid object to push against and there is no lengthening or shortening of the muscle.  Isotonic machines keep the force fixed throughout the range of motion and adjust velocity and weight to accomplish this. Many people train in water and can be used for things such as sprint training or rehabilitation, allowing for less joint compression and sheering forces. Resistance bands can be used by themselves or can be used with free weights to add resistance.

If proper guidelines are set and proper supervision is given, resistance training can be safe for children of all ages. It is crucial that children have been medically cleared before entering a resistance training program and that their level of physical fitness is at or above average. Resistance training should be progressive and never push a child beyond what they are physically capable of. If a program is properly performed and supervised, resistance training can increase physical performance as well as the possibility of an increase in mental focus. Along with the increased performance in sport, proper resistance training programs can decrease the rate of injury in sport participation. A supervisor of youth resistance training should always remember the importance of fun while designing and implementing training programs. Overzealous coaches and parents can cause injury to athletic participants or even burnout. The benefits of a lifetime of physical fitness far outweighs the few horror stories that have hindered the pursuit of youth resistance training in the past. The most important is that a child has fun and learns to accept a lifestyle of physical fitness. The more a child knows about what they are doing, the more they will appreciate the work that is being done and the more cautious they will be of themselves.