Biological age determination. When the growth rate is at its peak, we call this Peak Heigth Velocity (PHV). The start of the growth spurt is called the onset. This takes place one year before the PHV. After the PHV, the growth rate slowly decreases until the child has finished growing.

Determining the PHV is one way of mapping the child’s developmental age. The accelerated growth phase has 2 variables:

1. the timing (onset)
2. the rate at which the growth acceleration takes place.

The timing is when the growth spurt starts and the pace is the speed at which the growth occurs.

Each child has its own pace and timing, so trainers work with early ripeners, intermediate ripeners and late ripeners in 1 group. By determining the PHV in advance, trainers can give a different interpretation to the team and individual training sessions.

Determining the Age at Peak Heigth Velocity

How to determine when the maximum growth rate takes place, the growth spurt. The ratios between the limbs and the trunk are compared with the corresponding weight in order to determine the peak of the growth rate during puberty. (Mirwald, Baxter-Jones, Baily & Beunen, 2002)

This method assumes that in the growth phase the limbs start to grow first, which changes the ratios between weight, trunk and limbs.

Parameters for determining the APHV

• Gender
• Date of birth
• Length (standing)
• Sitting height
• Weight
• Measurement date

These parameters are translated by means of a mathematical formula to the age at which the child is at the top of the growth spurt.

How often to measure?

Children should be measured every 3 months. This applies to girls from the age of 7 and to boys from the age of 9. From the moment that the APHV indicates -1.5, it is recommended to measure once every two months. As soon as the APHV indicates +1.5, measuring once every six months is sufficient.

Nevertheless, one should not rely blindly on the results. The determination of the biological age by the PHV prediction is the basis, the trainer must make the nuances within the training based on the motor behavior of the child.

Measuring is knowing

With the help of the functionality of this site, trainers, coaches and exercise providers can keep track of the development of a child’s growth. Based on height, seat height, weight and the calendar age, an analysis can be made of the biological age of the child. Based on the analysis and the results, the user receives in one overview information about the growth, in which period the child is and what is and what is not wise to offer in a training.