Many parents focus on helping their child reach their full academic potential, with tutoring, homework, and structure.  Children have an athletic potential as well that is often overlooked, or taught that team sports alone will help them reach it.  While I don’t discount the importance of learning teamwork, team sports alone will not help a child reach that potential.  If they excel at a sport or sports, getting them involved early in strength and conditioning training can mean the difference between playing at the varsity level, possible college scholarship, or reaching the dream of professional sports.
For some parents, strength training may seem risky and unnecessary for their child.  As a kid I was always told, “You play sports, so you’re already in shape.”  Or one of my personal favorites “if you want to get stronger just go do pushups and sit ups.”  These commonly heard statements are absurd and could contradict the sport specific goals of nearly all sports.  One thing that trainers, coaches, and parents should know is that children and adolescents are not just small adults and need a training routine specifically designed for them.  Children and adolescents are physiologically different from adults, but this doesn’t mean that with the PROPER training that they cannot benefit greatly from strength training.  With the aid of resistance training, boys and girls are capable of significantly increasing muscular strength in addition to their natural growth and maturation during development.  Studies have shown that with the proper intensity and volume, children as young as 6 years old have benefit from resistance training.  Like sports, there is no minimal age requirement to participate in strength training.
How can strength training affect children and adolescents?
Early/late childhood: boys age range from 1-10 and girls age range from 1-8
Adolescents: boys age range from 10-22 and girls age range from 8-19
First and foremost, for children and adolescents, trainers must find a way to make training FUN as well as beneficial.  The concept of training can be intimidating.  Some children and adolescents look at strength training as work, and that’s exactly what it is.  Making up games/competition to incorporate into exercise programs can help keep the trainee engaged and excited to work hard.  So therefore, training children and adolescents has that added dynamic that requires some extra attention and focus by the trainer to ensure maximum gains/improvements and to inhibit frustration/boredom.  Another important aspect of training children and adolescents is language and communication.  Using appropriate words and tone can help encourage a trainee and maintain self-esteem; inversely, using too harsh a tone or using too strong or negative language can damage self-esteem.  If a child has low self-esteem and gets frustrated with exercise the odds of them working at 100% is low.  A trainer should ensure that there is not a negative correlation between exercise and satisfaction and self-worth.  Educating children and adolescents on the benefits of strength training and how it can make them feel better, live better and be happier will only help promote healthy living.
In adolescents, puberty is when we see a substantial increase in muscle mass (hypertrophy), and for most people this increase in muscle size is associated with an increase in strength and signifies the turning point at which training can begin.  Although this could be one view, neurological adaptation (nervous system development) is the main contributor for pre-pubescent children.  This helps with motor development and coordinated movements, illustrating how our athletic development is started even younger.  For example, throwing a baseball or catching a football requires an extremely high level of coordination and motor skills.  It should be looked at as a fundamental foundation to help aid in proper athletic movements later in life.
The main concern of training a child or adolescent is not only making significant gains, but also ensuring the safety of the trainee.  Whether it’s a trainer, coach, or parent that is working with a child or adolescent trainee supervision is very important.  Form and posture mistakes can be most detrimental to a new trainee of all ages and can ultimately lead to poor mechanics and/or injuries.  The proper biomechanics of an exercise can greatly benefit children and adolescents.  Taking the time to advise proper form and movements should be the first priority to any new exercise.  Sometimes it is easier to master the technique of an exercise with little or no weight added.  This will ensure that the proper movement patterns can be instilled with the program.
Avoiding injuries
A person that is training at any age has some potential of injury.  Proper training significantly decreases the risk of injury but cannot guarantee an athlete won’t get injured, just as an athlete could be injured in the heat of competition with any sport.  What proper training does guarantee is that the injury potential in competition will reduce dramatically.  Functional sport specific training will allow for identification of weaknesses and subsequent increase in balance, flexibility, strength, and coordination in vulnerable positions and movements.  This leads to an overall increase in strength and ability to perform in the athletic arena.  Regardless of the individual, when introducing resistance training it is always important to underestimate ones physical abilities regardless of how big or strong the child or adolescent may seem.  For most children and adolescents, resistance training will be a new experience, and pushing and exceeding their abilities too soon may put them at a greater risk of injury.  Starting slowly and cautiously to complete an evaluation and moving up when the foundation is established is the safest approach.
Should trainers worry about growth plate injuries in children and adolescents?
Growth plates are areas of bone that is still in development.  The growth plates are cartilage tissue at the ends of long bones and are important to normalize the length and shape of mature bone.  Growth plate fractures can be classified depending on the degree of damage to the plate itself.  All children that are still growing are at risk and the injury rates increase into adolescents.  Growth plate fractures occur twice as often in boys then in girls (this could be due to boys having higher involvement in high impact sports).  1/3 of growth plate injuries occur in competitive sports, such as basketball, football, and gymnastics.  1/5 of growth plate injuries are due to recreational activities, such as skateboarding, skiing, biking, and sledding.  There are five different classifications of growth plate fractures.  A type I fracture is a break in the bone that separates the bone end from its shaft; this type may require surgery which involves pins.  A type II fracture is when the bone breaks partially through the growth plate and partially through the cortical bone itself; this is the most common type of fracture.  Type III fracture is a break off of a portion of the growth plate and piece of the end bone; this type is more common in older children adolescents.  Type IV is a break through the bone shaft, growth plate, and end of the bone; these fractures commonly stop bone growth and are treated with surgery.  Type V is when the growth plate is compressed due to a crush impact; this type will almost always disturb bone growth but is very rare.  There are two major reasons for these types of injuries.  First, in children and adolescents, bones and muscles develop at a different speed so the bone may be weaker than the ligament tissue that it is connected by.  The second reason for these injuries can be attributed to high impact movements on the bone such as; falls, contact sports, or high rates of joint stress.  For trainers there has been an increasing concern for these injuries, especially with plyometric workout programs.  Plyometric workouts can be best defined as exercises that involve rapid stretching and contracting of muscles to gain an increase muscle power.  Even though there are limited studies on plyometric workouts in regards to children and with these exercises comes an increased concern focused on the high intensity impacts of plyometric exercises.  The major concern within plyometric workouts has focused on the intensity of depth jumps.  The depth jump is rated as the highest intensity of all plyometric workouts because of the amount of stress it puts on the lower extremities.  The proper mechanics of a basic depth jump consists of jumping forward off of a box on the ground with both feet.  Then rapidly descending into a squat position and exploding in the upward direction with a powerful jump.  The height of the box that is descended from will determine the amount of impact within the exercise.
Signs of growth plate injuries
A child that has experienced a growth plate injury may have some visible deformity.  Another telltale sign of a growth plate injury is consistent or severe pain at the joint.  If the child is unable to move or put any degree of pressure without experiencing pain then there could be a growth plate issue.  If any of these signs are apparent while training a child, then the trainer should immediately stop the session and should inform both the parent and child to get an examination by a licensed physician (trainers are not licensed physicians and should never diagnose a trainee).
Bone mineral density (BMD) and bone mineral content (BMC) are very important in a maturing body.  Bone mineral content refers to the amount of bone mineral in grams.  Whereas, bone mineral density refers to the grams per centimeter squared (g/cm^2).  Children are considered “moving targets” and bone mineral content may not apply to them the same way it does to an adult (heavier bone may not reflect stronger bone).  The age at which bone mineral content will most likely reflect bone density is post-adolescents.  Bone mineral density is most advantageous to the strength of children and adolescents bone make-up.  The most crucial time for development and strengthening is between the ages of 10-15 (for most this is adolescents).  Bone mineral density can be developed by performing weight bearing activities.  The more vigorous the activity or exercise is the greater the increase in bone strength (BMD).  This may seem to contradict the theory on growth plates, and it does.  This is why children and adolescents are not miniature adults.  There is an overlap in performing more intense exercise as children and adolescents because of the risk of growth plate injuries.  Keeping the trainee in a healthy intensity range will help benefit the child without injury.  Medium to high intensity plyometric workouts can be safe for a child to maximize healthy bone strength.
Make training children and adolescents simple
There seems to be a simple solution to this concern with children and adolescents, and that is to avoid this particular plyometric exercise or any workout that can put a high level of stress on joints.  There are plenty of resistance training exercises, including plyometric exercises, that children and adolescents can do without over stressing their joints such as most power lifts, most strength training lifts, repetitive jumps, bounds, different throwing exercises, etc.  Some times as trainers, we focus more on what we can’t or shouldn’t do in regards to training children and adolescents and inadvertently forget what we can do.  There are far more exercises that are safe for children and adolescents than ones that are not.  Some other important factors to keep in mind for training children and adolescents are nutrition, proper recovery times, and educating youth sports coaches about the benefits of strength and conditioning training.
Growth Plate Fractures. “American Academy of Orthopedic Surgeons“.   January 2010
Grabert, D.  Structuring a Resistance Training Program to Combat Childhood Obesity.  “National Strength and Conditioning Association.”  2012


These resources are for the purpose of personal trainer growth and development through Continuing Education which advances the knowledge of fitness professionals. This article is written for NFPT Certified Personal Trainers to receive Continuing Education Credit (CEC). Please contact NFPT at 800.729.6378 or with questions or for more information.