Biological Versus Chronological Age in Youth Sports

We’re all familiar with that stage of childhood when movement gets a little awkward due to rapid growth. But sometimes we forget that this physical transformation happens at different rates in different children. Any coach who works with kids knows the tremendous and sometimes unbelievable difference between two youth athletes of the same age, especially in the ‘tween and early teen stages. A recent study in the Journal of Strength and Conditioning Research asked which methods are best for determining these differences for better athletic placement.


Chronological age (the one we normally go by) is not the same as biological age, since some athletes mature physically at a different rate than others. Much like in academics, chronological age isn’t always the best way to determine where a child’s placement in sports. However, most professionals are better prepared to test children for academic placement than athletic placement.

The researchers acknowledged that although measuring bone growth is the most accepted method for determining physical maturation, it is also the least accessible. To measure bone growth accurately requires expensive medical testing. Generally X-rays are involved, and although the researchers in this study stated that the radiation levels are safer than we usually think, it’s something many parents would seek to avoid.

Assessing sexual maturation is another method, but it too can only be undergone in a clinical setting by doctors. This option requires great care and concern for the child’s wellbeing  and is less accurate of a method, anyway. Thus it is perhaps the least useful of all methods.

A final method that seems to be both practical and fairly useful, is called peak height velocity (PHV). PHV is the time in a child’s life in which they attain the most rapid height growth. PHV tends to coincide with sexual maturation and rapid changes in bone structure. In girls, this typically happens at around twelve years of age, and in boys at age fourteen, although it can occur more than a year before or after these estimates.

PHV can only be accurately ascertained with long-term height measurements, but is nevertheless a useful method for determining whether or not a child has achieved the level of maturity needed for certain exercise routines. The researchers in this study suggested that hypertrophy-based routines are only useful in youth athletes who are beyond PHV, since the hormones required are not present in sufficient quantities until after that point. The researchers also noted that resistance training is appropriate – within an otherwise safe environment – for any youth athlete. However, the recommended program for children who have not yet reached their PHV should focus more on strength and coordination, as neural plasticity is highest at that time.

So the focus of training should be based on physical maturation, which can occur at various times depending on each child’s individual variations. The simplest and yet highly effective method for determining this seems to be PHV, but it needs to be tested regularly. The most important feature of any youth training program, regardless of maturation, is fun, so keep training positive at all times.

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A 5-Step Approach to Training During Adolescent Growth Spurts

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We have all seen the awkwardness that accompanies a period of growth for youth athletes. Some of us have even experienced it. The fastest runner on the team begins tripping over his or her feet. The once graceful dancer is all arms and legs. The number-four batter moves down in the lineup because he or she can’t get the timing right. 

Adolescent Growth Spurts (AGS)

According to the book Bright Futures in Practice: Physical Activity, published by Georgetown University, a temporary decline in coordination and balance may occur during puberty because of rapid growth. In many cases, this decline is not only demonstrated through sports performance, but also in regular physical activity. This experience can be frustrating for coaches, trainers, youth athletes, and parents, particularly if this decrease in athleticism is interpreted as a lack of skill or effort.

"Based on sports fundamentals, AGS training should focus on movement-based strength, overall fitness, speed and agility, plyometric work, and instilling confidence."

Knowing that adolescent growth spurts (AGS) and the accompanying athletic awkwardness are normal in this phase of puberty does not make it any easier for the youth athlete. As well as physically affecting sports performance, AGS can also affect athletes socially and mentally. It can also have detrimental effects on core strength, postural control, and performance - including skill, speed, coordination, and agility - as athletes struggle to adjust to their rapidly growing and changing bodies. 

Youth athletes need to know they are not alone in experiencing a lack of coordination and balance during and after growth spurts. In her article, Hockey Training During the Adolescent Growth Spurt, Kelly Anton explains:

At their fastest, boys grow by four inches a year and girls by two-and-a-half inches a year. As height increases, the center of gravity lifts. This happens so quickly that the brain does not get a chance to calculate the new rules for balance. On average, boys grow fastest between 14 and 15 and girls grow fastest between 12 and 13. Girls finish their growth spurt at 18 while boys need another two years before they finish growing at about 20.

Adolescent coaches and trainers recognize the physical changes that occur during AGS can decrease overall skills, speed, coordination, and agility. Coaches, trainers, parents, and athletes must also be aware of the athlete’s susceptibility to training injuries, especially during and after AGS.

How to Deal With AGS

The good news is that coaches and trainers who are aware of AGS can help alleviate and reduce athletic awkwardness by incorporating specific aspects of training into practices and training sessions. The Soccer Speed & Agility Clinic ebook, published by the Soccer Fit Academy, addresses these particulars of training. Although this book is geared specifically to soccer players, the common-sense approach of training through AGS is applicable to youth athletes of every sport.

Based on sports fundamentals, AGS training should focus on the following five factors:

1. Movement-based strength
2. Overall fitness
3. Speed and agility
4. Plyometric work
5. Confidence

It is important to note that while AGS is considered phased training, the fundamentals may be used separately or may be merged. The emphasis in AGS training, as opposed to a regular training session, is that particular attention is paid to the execution of proper biomechanics through all aspects of training for a growing athlete.  

Progressing from this point, coaches and trainers can start to increase the load and intensity of the drills as athletes become stronger and more confident in the movements.

1. Movement-Based Strength

Beginning with movement-based strength, coaches and trainers should look at the basic movements of the specific sport. Across the board, most movements will center on running, squatting, jumping, lunging, pivoting, and rotating. The object in this phase of training is to make these movements more rhythmic in nature through repetition, through recruiting correct movement patterns, and through building confidence in movement strength.

After these movement patterns are mastered, speed is added, with specific attention paid to performing drills without losing form. Progressing from this point, coaches and trainers can start to increase the load and intensity of the drills as athletes become stronger and more confident in the movements.

RELATED: Foundational Training for Youth Athletes: Are You Doing It?

2. Overall Fitness

The second phase of AGS training is overall fitness, which is defined as the level of play that allows an athlete to perform optimally. Pre-season conditioning is largely responsible for the overall fitness of an athlete, the focus of which should be optimal athletic performance late in the game and late in the season. In addition, fitness largely contributes to decreasing sports injuries.

3. Speed and Agility

In off-season training, building a strong speed and agility base follows closely with the first two goals of training through AGS. As athletes progress through growth spurts, they must relearn how to control their bodies in direction changes, changes of pace, and acceleration situations. They must relearn their balance points and readjust their center of gravity. Again, stressing the repetition of correct movement patterns, with a gradual increase of speed and intensity, is key to developing speed during and after AGS.

"The athlete must believe in his or her training, his or her abilities and skills, and his or her past experiences in order to prepare for and perform well in an event."

4. Plyometrics

Plyometric exercises are the final physical phase of AGS training. As discussed earlier, this area can be merged into other areas of training, especially with strength training, to help develop explosive strength, speed, and agility.

5. Confidence

Confidence is taught and worked on throughout all phases of AGS training. The athlete must have confidence in the hours spent mentally and physically preparing for the event - the repetitions, the workouts, and the coaching.The athlete must believe in his or her training, his or her abilities and skills, and his or her past experiences in order to prepare for and perform well in an event.

Take Time to Work the Basics

Speed and agility, as well as other sports skills, don’t just reappear after growth has slowed or stopped. That means coaches and trainers must understand how to retrain athletes in their movement patterns. To do this, the training program must emphasize movement, rhythm, and coordination over strength, fitness, and power.

RELATED: 5-Phase Adolescent Strength Program for Creating Good Movers

This is not to say that strength, fitness, and power are not important. They are absolutely essential to an athlete’s optimal performance, but in relation to sports performance and AGS, they must come after the athlete’s mastery of movement, rhythm, and coordination.

By implementing a training program that accommodates AGS, coaches and trainers canalleviate coordination and balance issues, decrease athletic awkwardness and injuries, and help young athletes reach optimal performance levels.

Overuse injuries are a form of neglect! I bet you didn't look at it that way...

What if I told you that overuse injuries could be thought more of as injuries of neglect? You’ve decided to neglect training certain muscle groups or maybe you neglect key recovery strategies. You neglect to care for your body properly.

Think about it: by definition, neglect refers to failing to care for something properly. And if you have an overuse injury, you’ve most certainly not cared for your body properly. Of course, this doesn’t mean you intended for the injury to happen. But nonetheless, it did.

Now, think about our youth athletes for a second. Think of the shear number of injuries that they are experiencing. Overuse injuries. Injuries of neglect.

Our Responsibility to Our Children

I say this not to offend, but to make you truly understand the impact we have on our young athletes as parents, coaches, organizations and professionals. I am telling you this so that you know that the large majority of youth athlete injuries are entirely preventable.

But, due to our neglect, we are failing these athletes. They are getting injured. And these injuries are staying with them right into college, university, and beyond. This affects not only their athletic potential and their athletic careers, but also their life in general.

Hockey and the Youth Athlete

Now, I’m going to talk about hockey for a minute. I live in Canada where we really do live and breathe hockey. In fact, one of my favorite photographs was taken during the Canada versus United States game in Sochi in 2014. The picture? A snapshot from a traffic camera of one of our busiest highways, which at that moment didn’t have a single car on it. Even more, every business and establishment that I know had the game live streaming that day so no one had to miss out. How could we? They were playing our game!

  

In my practice, pretty much every client I have has a connection to hockey in some way, shape, or form. Parents spend a fortune on their kids for hockey leagues, camps, tournaments, the best gear, and so on and so forth. But maybe that is a problem. Are we pushing our young athletes too hard without realizing it?

The truth is, we really are. We are neglecting them by not properly caring for their bodies, especially during times of high frequency, high intensity sport training.

Youth athletes who specialize in one sport, in this case hockey, usually play it year round in order to gain better skills and the competitive edge to keep them at the top of their game. They aspire for greatness, hoping to one day make it to the National Hockey League.

But this is where our neglect comes in - and we let this happen. We let it happen by not making these young athletes take the proper recovery measures and not addressing their high risk of injuries due to factors including improper technique, ill fitting equipment, training errors, coach or parental pressure, failure to recognize injuries early, or inherent muscle imbalances.

All of these things, topped with the high repetition involved in their sport and little-to-no strength training, are a devastating combination for our young athletes. Poor movement and improper technique lead to muscle imbalances, as the body has to compensate for additional pressure and torque placed on tendons, growth plates, bones, and joints. With further training, these muscle imbalances become more pronounced and overuse injuries start to occur.

Youth Athletes Absolutely Must Strength Train

Youth athletes are not simply mini adults. They lack strength, mobility, and coordination, and they also usually have inherent muscle imbalances.Therefore, we need to physically prepare our athletes for their sport.

These athletes need to work with specialists in strength and conditioning and prehabilitation in order to ensure they have adequate strength, endurance, balance, coordination, and mobility to perform the highly repetitive action of their sport. If you fail to do this, I can guarantee that your young athlete will be plagued with an injury, and sooner rather than later.

In fact, it is these very athletes that I treat at the university and college level. They come to me awaiting surgery to repair the damage that could have been easily prevented with a proper strength program during their youth. Don’t let it get to this point.

Ensure Adequate Recovery

Recovery is absolutely crucial for our youth athletes. And I don’t necessarily mean sitting on a foam roller or stretching, though that is part of it.

No, when I speak of recovery, I am referring to adequate nutrition, sleep, hydration, and time off from sport, as well as active recovery techniques including mobility and soft tissue work. If one of these factors isn’t in check, then you are putting your young athlete at a much greater risk of overtraining.

Mix It Up

Encouraging your youth athletes to play different sports throughout the year will prevent the sport-specific repetitive stress and overuse injuries they will experience from year-round, single-sport participation. Youth don’t need to be playing hockey (or football, or lacrosse, or x, y, or z) year round. They need time off from their sport so they can recover. Otherwise, they end up starting every new season tired or injured.

Even if young athletes aren’t injured, there is a good chance that without some time off they will start to plateau in terms of skills development. Going from in-season training to off-season camps back to back with no rest is not going to help your athlete in the long run. You have to look bigger picture.

Signs Your Athlete Is Over-Trained or Under-Recovered

As parents, coaches, and trainers, we need to pay attention and be sensitive to any changes in our youth athletes in terms of performance and attitude that might indicate they are being pushed too hard. The following is a list of signs to look for in your youth athletes:

• They used to be excited about their sport/training.
• Their performance stresses them out. A poor practice, or game will often ruin their day.
• They seem to always be sore or have lingering injuries/pains.
• Their sleep pattern has changed or become irregular.
• Even if they do sleep, they don’t feel rested.
• They crave more sugar and carbs then they used to.
• They’re getting sick a lot or sickness lingers.
• They’ve hit a performance plateau or performance has started to decline.

And though I specifically referenced hockey here, know that the same holds true for all sports. Remember, youth are not mini adults. They shouldn’t be treated as such. We need to pay close attention that we are not neglecting to care for them through overtraining or under-recovering. More is not always better, especially when it comes to youth sport.