Resistance Training in Children
It is a common misconception that children do not benefit from resistance training programs. In fact, the notion that resistance training in children stunts growth and development is also a common misconception. Physical activity (specifically weight bearing) is shown to generate compressive forces, which helps with bone formation and growth, in addition to the role it plays with strength gains and a reduction in childhood obesity. While there are a number of benefits associated with youth resistance training, there are also many factors that need to be taken into account when designing the programs.
Children’s maturation level varies depending on the individual. Age does not determine a child’s maturation. Chronological age (actual age in years) shouldn’t determine the load, volume, intensity, and duration of a resistance training session, but biological age (physical maturity or sexual maturity, on the other hand, should. When training children, it is important to know that resistance training results are negligible prior to puberty in reference to muscular hypertrophy. This means that a team of 12-year old boys may not all see increases in muscular size as a result of resistance training: only those who’ve begun going through puberty; however, they all should show improvements in muscular strength. When designing a resistance training program for youth, professionals have to take into account the biological age of each participant. Signs of puberty to look out for include (a) girls: menarche, and (b) boys: pubic hair, facial hair, deepening of the voice. The onset of puberty (or lack thereof) is a guideline to determine the volume, intensity, load, and duration of exercise for the individual. While children who are going through puberty have a greater capacity to perform at higher levels, it can also pose a great risk. During puberty, kids may experience a peak height velocity (growth spurt). In the event of a growth spurt, young athletes are at a greater risk for injury due to bone weakening, muscle imbalances, and muscle tendon tightening. In this case, professionals may have to decrease the training characteristics or modify the resistance training program to avoid injury.
Resistance training will help boys and girls increase muscular strength, power, and endurance beyond that of growth and maturation. Children as young as 6 have shown improvements in strength as a result of resistance training and most pre-adolescent children will show strength gains on average between 30 and 40% in untrained children compared to those who are not engaged in a resistance training program. Unfortunately, children’s strength gains often return to their previously untrained characteristics as a result of detraining, possibly due to schedules or decreased motivation. Because of this phenomenon, a child who is participating in a resistance training program during pre-adolescence should not undergo a detraining phase if he wishes to maintain and continue to enhance his strength gains.
By now we know that resistance training in youth indicates increases in muscular strength, power and endurance in addition to increases in health and fitness-related measures, such as a reduction in the risk of sports injuries, motor skill improvements, and sports performance enhancement, but what about muscular hypertrophy? Children who undergo resistance training will inevitably see increases in strength, but due to the lack of testosterone prior to puberty, muscular hypertrophy is not often seen. This difference may be attributed to strength improvement as a result of neural factor enhancement, such as motor unit activation and motor unit recruitment. This difference in strength and hypertrophy improvements further highlights the fact that children are not miniature adults: training programs for youth should not be designed based on adult exercise parameters, rather the physiological characteristics of the participants as individuals. While adults have very specific guidelines for repetitions and sets per exercise, children’s training programs will vary amongst the participants. Professionals should establish a repetition range (e.g. 8-10 reps), and via trial and error determine the maximal load that can be performed within the established rep range. Increases in load, reps or sets at every training session is not necessary for youth. Strength gains will continue to be made even if the program characteristics are similar from session to session. Instead, professionals should focus on proper form and technique. If proper technique is not occurring with the amount of stress being applied, the load should be decreased.
There is no age requirement to begin resistance training, however, there are a couple of pre-requisites. Children should want to begin this type of training program and they should also have the emotional maturity to follow directions. When working with children in resistance training programs, professionals should focus on emphasizing proper technique, as opposed to the amount of weight lifted. Competition amongst youth in resistance training poses a greater potential to induce injury; therefore, priority should be taken on skill improvement, personal goals, and successes, and having fun, rather than trying to out lift peers.
Guidelines for Resistance Training in Youth
- Educate participants on the risks and benefits of resistance training
- Individualize training programs (load, intensity, volume, and duration)
- Dynamic warm-ups prior to exercise
- Static stretching following the exercise
- Sets: 1-2
- Reps: 6-15
- Incorporate single and multi-joint axis exercises
- 2-3 nonconsecutive training sessions per week
- Program variation throughout the year