This blog comes from our colleague Jeff Overholt, Co-Founder of Golf Performance Coaches and PGA of Ontario 2013 Coach of the Year. This entry was initially published on the Golf Performance Coaches' blog under the title of "'Growing Up' - Acorns Becoming Oak Trees". Please visit their site for more excellent junior athlete development information.
Can you guess which of these junior golfers is the oldest? Which player would have an advantage if they were all competing on a golf course which was around 5500 yards?
Believe it or not the player on the left is actually the youngest (chronological age), but he is the oldest from a development age standpoint. Developmental age refers to the child’s age of physical, mental, emotional or intellectual maturity as opposed to chronological age, which represents the number of years and days which have elapsed since birth.
These concepts are very important for coaches and parents to understand if they have athletes of any sport between 10 – 15 years of age. During this time, children typically go through their growth spurt and hit a critical marker in their development called Peak Height Velocity (PHV).
PHV refers to the point in time where an athlete is growing at the fastest rate – it is the peak of their growth spurt (this typically occurs for boys between the age of 12 – 15 and girls between 10 – 13). Throughout this time of accelerated growth, the athlete’s body will go through many changes which will have a major impact on their performance on the golf course. Can you imagine the difficulty of hitting a pitched ball if after a few weeks away from the game your head was a few inches higher from the ground?
During the growth spurt an athlete’s nervous system is really being put to the test – resulting in the need to make countless adjustments to their motor patterns. From a physical standpoint, flexibility is often compromised due to the fact that their bones are growing faster than their muscles – thus placing those muscles in a higher level of tension. You can imagine that at this stage of development mistakes and errors are definitely in the cards. (see previous post on “Are you learning from Mistakes”)
It makes you wonder – is it fair to expose our young athletes to high levels of competition while their body is going through so many changes? Is it fair to “judge” our junior players when the control of their body is really out of their control?
Either way, the onset of PHV is a critical time period to acknowledge as it will dictate which baseball skills should be prioritized in the gym and on the diamond to ensure athletes get through the growth spurt with minimal damage to their body. So what can be done when your athletes and children are approaching PHV?
First of all, awareness is really the key and you must have a strategy in place to find out when they are going through their growth spurt and more specifically when they hit their PHV.
Measuring growth rates can be done in several ways, but I would highly recommend you follow the phases outlined below – referenced from “Role of Monitoring Growth” – CS4L resource paper.
Phase 1: Chronological age 0 to 6
- Very rapid growth
- Measure standing height and weight on birthday
Phase 2: Age 6 to the Onset of the growth spurt
- Steady growth until the onset of the growth spurt
- Measure standing height and weight every three months
- If measurement takes place outside of home, replace birthday with the starting point of the annual training and competition cycle
Phase 3: From the onset of growth spurt to peak of PHV
- Rapid growth until peak is reached
- Measure standing height, sitting height and arm span every three months
Phase 4: PHV to Slow Deceleration
- Rapid deceleration
- Measure standing height, sitting heights, and arm span every three months
Phase 5: From Slow Deceleration to Cessation
- Slow deceleration of growth until cessation of growth
- Measure standing height every months
Phase 6: Cessation
- Cessation of growth
- Measure height and weight on birthday
It is essential that you are consistent with the accuracy of the measurement as small variations can make large impacts to the growth curve. I would recommend that the coach takes ownership of the measurements around the ages of 6 – 9 and makes this process a part of their coaching sessions at regular intervals through the years.
Another great resource for calculating PHV has been developed by the University of Saskatchewan and provides a prediction based on the athlete's standing height, sitting height, weight, and age. We have used this resource for several years and is a quick and easy way to help better understand where your athlete is in their growth spurt.
The topic of Peak Height Velocity is a popular theme across sports these days, and for good reason. Not only does awareness of PHV help us to better coach and support our young players, but it also helps us to design programs that enable them to grow most gracefully and without risk of injury. By acknowledging the onset of PHV we can better prepare our young players (and their parents) for the possibility of inconsistent performances and fluctuating emotions.
Jeff Overholt - Golf Performance Coaches