Training Age – Growth and Maturation

Children cannot be simply treated as miniature adults. Those of similar chronological age may vary significantly in their progress toward the mature adult form. Even within the same age group, kids are at different stages of readiness for training. To understand what can be trained when, training guidelines are linked to the phase of growth and maturation.

Pre-pubertal children are those that have not yet gone through their adolescent growth spurt, or their period of most rapid growth (peak height velocity). Pre-pubertal children are often less than 12 years of age in females, and less than 14 years of age in males.

Their peak neural maturation occurs from age 0-7 and continues at a rapid rate up to age 12 when the window begins to close. During this stage it is advantageous to draw from the secondary fitness characteristics, to create exploratory-based challenges for which the child must solve the puzzle of how to correctly coordinate the exercise. Children improve balance, coordination and body awareness from neurally complex exercises. Training adaptations include improved neural networks.

The power of neural improvement is evident following strength training programs when pre-pubertal participants enjoy significant strength improvement but do not experience any muscle hypertrophy. As such, young children are better served staying off of miniature weight machines that demand the lowest neural muscular input and rather strive to coordinate strength outputs in supine, prone and CKC positions using stability balls, BOSU’s and other accessories.

Most young children are fairly pliable, but some will also be hypermobile. Loose joints can lead to early osteoarthritis and osteophyte formations (bone spurs) in the body’s attempt to increase bony stability around joints. For these children, avoid further stretching and instead focus on building strength – through a full range of motion.

The heart organ of children this age is of course smaller and as such increases in cardiac output are reliant on elevated heart rates (since their stroke volume is smaller). It is common to elicit heart rates of 170 bpm at this age, compared to post-pubescent children who would train aerobically at 140 bpm. It is noteworthy that pre-pubescent bodies already have relatively high oxygen extraction capabilities so any given training only generates about 50% of the improvement one would expect in adults. Of course kids this age cannot focus on 60 minutes of continuous, repetitive exercise. Even 90% of adults won’t do this! But shorter 15 minutes bouts and integrating sustained effort within a game-like environment can do the trick, sustain their attention and allow them to have fun.

The pubertal phase of peak height velocity lasts from 12 – 18 months and brings with it several training considerations. General considerations for this period include reduced distal loading of the limbs, and reduced high intensity work to avoid over-training or inflammation of the bone-tendon connections. During this period the levers increase in length, while the muscles do not respond until later, so even basic locomotor skills may appear awkward during this phase. Additional balance and agility drills help them become accustomed to their new height, limb length and centre of gravity.

Many parents and coaches express dismay at the frequency of trauma and injury during this stage. As the skeletal system has matured without a concomitant increase in muscle girth and strength, pubertal children have less stable joints which are less reactive to lateral and deceleration forces. Attention to proficient movement skills and proper braking and loading through deceleration will allow them to continue to train through this stage and help prevent sport injuries.

However this can be exacerbated when longer levers allow for faster running speed from biomechanical efficiency. Higher speeds require more aggressive braking, which pubertal bodies are not suited to handle. Strength training is vital to help the muscles catch up. For pubertal kids, many fitness books discourage weight training and suggest strength training with their own body weight. However, I find that many kids in this phase cannot handle their own body mass and better execute exercises with light dumbbells and resistance tubing.

Post-pubertal children are those that have gone through their adolescent growth spurt, after peak height velocity but prior to full skeletal maturity. After peak height velocity, post-pubertal children will experience an accelerated increase in mass, with rapid gains in muscular development, along with further hormonal maturation. At this stage they have the circulating hormones to achieve gains in muscle girth as well as benefit from anaerobic conditioning.

In this phase trainers’ can begin to increase the weight training load, stimulating muscle hypertrophy by optimizing time under tension through slower eccentric contractions. This age group can also safely progress to more powerful lifts that feature higher tempos.

These and other critical growth and maturation moderators must be taken into consideration in the development of the training curriculum, and the subsequent exercises delivered so that the child is receptive and enthusiastic.

The Twist Team!