Growth, Maturation and Development

Don’t fall foul of losing potential champions, and life-time participants, because you are focusing on the ‘superstar’ 14-year-old who is dominating now. The truth is they may be an early developer! They hit their growth spurt earlier than the rest or were simply born earlier in the year.

A ‘summer baby’ or ‘late maturer’ could be a future champion and deserves equal time, support and opportunities. 

Every child develops at their own unique pace. Some sprint ahead in physical growth while others bloom later. Some show early technical mastery while others take time to develop coordination. 

This natural variation in growth and maturation has profound implications for how we coach, train, and support young athletes. 

And let’s not forget ‘training age’…

Two 13-year-olds attend your session. One may have been playing since they were six with regular coaching and practice, whilst the other may have decided to try your sport or activity after enjoying a six-week block in their Physical Education lesson!

Understanding the influence of Relative Age Effect and biology

We have three teenagers, who are all under 13. One is born in September, one in January and one in August. If we consider Relative Age Effect, often referred to as RAE, this is when an individual is relatively older than another person in the same year.  In sports and during development this ‘advantage’ can be significant.

Participating in school sport, the teenager born in September will be almost a year older than the person born in August.  A year more growing, developing and experiencing opportunities. Before you think ‘that’s not much’, they have been on the planet 7.5% longer! That’s a big advantage in the teenage years. If their sport or activity works on a calendar year, the teenager born in January has the advantage over both the individuals born in August and September. Hopefully, you are seeing the advantage of just knowing when a participant is born!

Now let’s consider biology. The same three teenagers are competing against each other, and whilst chronologically they are all 13, one may be biologically 15 and another biologically 11. A four-year developmental gap. So, are you seeing potential or maturation?

I know you are saying, ‘I am a coach not a sports scientist or physiologist’, but understanding growth and development is a game changer.

Training programme and practice design

Align training loads (volume and frequency) and types of training (skills, movement, physical development, psycho-behavioural, social skills, tactical understanding) with developmental stages to reduce the risk of injury and optimise development. 

Frequently during adolescence individuals are selected for representative programmes which includes an increase in load and should be supervised carefully. Regular communication with other coaches across programmes to monitor total workload is essential. A good rule of thumb is that an individual’s weekly workload dose, in hours, should not exceed their chronological age.

Another variable in load is the competition to training ratio. The intensity and impact of competition is a significantly higher demand. Ensuring adequate preparation and quality training to compete is essential. 

Conditioning to play, rather than play to be conditioned. 

Different ages and biological stages require different approaches, even within the same chronological age group. If you coach wider age bands, the differences are likely to be more significant. 

Peak Height Velocity (PHV), often referred to as ‘growth spurts’ when the bones of the body grow faster than the muscles and ligaments, between 9-10cm annually, can temporarily affect coordination and skill execution, requiring programme adjustments. 

Imagine waking up and finding your limbs are 3cm longer than they were yesterday. This affects the ability to move, change direction, catch and pass, often referred to as adolescent awkwardness.  During this time, your participants need time to adjust and get used to their ‘new’ body. Focus on gross motor skills rather than fine motor skill refinement. If the sports require an implement this may require them to have a bigger size.

Participant well-being and safe practice

The adolescent growth spurt (Peak Height Velocity) is a period during which participants have an increased risk of injury. The growth plates within bones are rapidly growing and are weaker and vulnerable to overuse injuries at this time because of a temporary decrease in bone mineral density. Often as the bones lengthen rapidly, the muscles and tendons are not able to adapt as quickly, resulting in tension and strains. High impact activities and repetitive actions are especially high risk during this time.

The use of an effective warm-up and gradually progressing the intensity and load during sessions allows the body to adapt. The introduction and regular use of a neuromuscular training programme significantly reduces the risk of overuse and acute injuries such as ACL tears.

Selecting and planning activities within sessions that are less demanding on joints as well as ensuring adequate rest and recovery. Whilst always important they are crucial during the growth spurt to allow for repair.

Encourage participants to take responsibility and listen to their bodies to ensure they have adequate rest and recovery and modify the session intensity when needed. Adolescent participants who sleep less than eight hours per night have been shown to be 1.7 times more likely to sustain an injury.

Coaches should also consider maturation differences during training to prevent mismatches of participants who are physically different. Whilst in competition it is more challenging, especially in team sports, the first priority of all coaches is to ensure the safety of their participants and make professional judgements based on the situation. 

Many sports now consider the use of bio-banding, the grouping of adolescents based on PHV into three groups. Pre-PHV, Mid-PHV (during the onset) and Post-PHV. Whilst banding can be useful from a physiological and physical maturation perspective, considerations from a social, psychological and self-esteem perspective should also be considered.

Long-term Development

Early specialisation may lead to overuse injuries. A diverse movement and activity programme is beneficial for all participants, even more so during the adolescent growth spurt. Awareness of windows of trainability during the growth spurt is important.

Pre-adolescent or Pre-PHV

Foundation of fundamental movement skills and general athletic ability and skills:

• Receptive to motor learning.
• Discover movement opportunities and capabilities.
• Whilst some strength gains are possible, these are greater post puberty.
• Exploration through movement puzzles, challenges, games and negotiating obstacles.

Onset of Puberty or Mid-PHV

Significant changes and differences in genders* 

Male

• Period of rapid growth in height and mass.
• Strength training with a focus on quality of movement and repetitions after 12-18 months after PHV.
• Changes in limb length and centre of gravity requires regular coordination activities to recalibrate.

Female

• Puberty occurs earlier, averaging around 12-years of age.
• Whist girls also increase in stature, mass and limb length, they do not have the same increases in strength gains. Introduction of a strength-based programme is extremely helpful at this time, developing the muscle chain from ankle, through to knees, hips and trunk.
• Emphasis on endurance immediately post growth spurt.

* Gender at birth, due to the biological changes that occur during puberty.

Post-PHV, stability

For girls, this is typically around a year and a half following the main adolescent growth spurt.

• Average is 14 years of age but does vary according to the individual.

For boys, this is typically later, 2 years plus post-PHV.

• Opportunity to focus on making strength gains, speed increases. 

Talent identification, selection and development

If you coach in representative or talent pathway or have participants within your group or team that are involved in a pathway journey, there a few things to consider.

Firstly, selection in many sports takes places at a crucial stage of individuals’ growth and maturation, when many physical characteristics are unstable, and often individuals are undergoing change in:

• height
• body mass
• body stature
• emotional, psychological, and cognitive changes. 

Whenever possible delay selection, continue to monitor and develop the widest talent pool possible until physiological characteristics become stable. 

Constraints of the pathway and system may not allow for everyone to have equal opportunity and assessments have to take place.  

Two simple considerations. Monitor over time: the bigger the window of monitoring, before, during and after adolescence growth spurt, the better the decision. Avoid the snapshot decisions in a moment or single session. Secondly, ‘many eyes, many times’: the more people that contribute to the discussion from observation the more likely a better outcome.

When a decision has to be made, how is the feedback provided? Is it helpful? Does it provide ‘work ons’ for the person? Does it provide a way to progress, or, if exiting a pathway, a way to return?  Remember, it’s a pathway and not a dead end!

Ultimately, things change, and consideration should be given to opportunities for individuals to transition into and out of the pathway, with support. Keeping the door open for as many people as possible not only ensures a quality pathway, it also makes sure that it is a positive experience for the individuals involved.

Psychological considerations and social aspects

Maturation is more than physical changes; young people also develop their cognitive and emotional development stages at different times and require adapted coaching approaches. Don’t assume that the athlete that is physically bigger (RAE or early maturer) is also advanced in their cognitive or emotional development.

During the teenage years, a shift occurs as young people’s peer groups and adult support become more significant influences as they begin to adopt certain values, beliefs, norms and behaviours.  

Coaches, as role models, and the coaching programme, offer an opportunity to develop values and life skills including:

• loyalty
• teamwork
• leadership
• co-operation
• responsibility
• commitment.  

Consider how you introduce these implicitly through your coach behaviours and coaching conversations or explicitly through your programme and session design.

Peers influence an individual’s sense of identity. Pressure from peers can impact self-esteem, body image and self-worth as their brains alter and change, making them more aware of social situations and their immediate peer group. Through social media this can have further ripple effects as the teenage brain is more attended to the reward situation and the desire to ‘fit in’, impacting ways of speaking, dress sense and interactions with adults.

Be aware that their identity during this time can be heavily linked to their ‘athletic identity’, with a heavy focus on activities linked to their progression, representative opportunities and potential careers.

Providing constructive feedback and supporting transitions

As a coach supporting individuals through this developmental stage, it’s crucial to recognise how their focus and motivation for sports and physical activity may evolve. During the transition from childhood to adolescence, young people begin to take ownership of their lives by choosing commitments that provide a sense of belonging and support. This period is also an opportunity to introduce positive habits and behaviours in your sessions.

Consider the changing coach, participant and parent/ carer triad relationship at different stages of the individual’s development, balancing an increased personal responsibility for the individual, whilst still maintaining connection, communication and support from the parent/ carer.

Maintain an awareness of your participants’ body image and their concept of self, promoting and discussing these positively and challenging negative conversations and comments.

If you are working in a representative setting or talent pathway or coach a participant who has attended an assessment day (selection, trial), consider the impact of non-selection on the individual and how you can support their transition.

Summary recommendations:

• Remember children are not mini adults.
• Individuals mature and develop at different times.
• Individualise training approaches.
• Consider the purpose of competition, focus on the development opportunities over volume.
• Communicate expectations and reasons for adaptations and changes with participants and parents/ carers.