Growth spurts and why coordination temporarily moves backwards

What actually changes during a growth spurt

During rapid growth, limb segments lengthen quickly and body proportions shift over a period of months rather than years. The nervous system controls movement using an internal model of the body's dimensions and mass distribution. When those dimensions change faster than the model updates, movements that were previously accurate begin to miss.

The athlete experiences this as sudden clumsiness in skills they had performed reliably for years. It resolves as the model recalibrates, though the process takes time and cannot be hurried by additional practice alone.

Why strength lags behind size

Bones lengthen before the muscles crossing them adapt fully to their new length, which temporarily alters the mechanics. Muscular strength relative to the longer levers is reduced during this period, so the same movement requires more effort. Flexibility often appears to decrease, which reflects the changed bone length rather than any shortening of the muscle.

The combination leaves a young athlete simultaneously longer, relatively weaker and less accurate than they were. Understanding this as a temporary and expected state rather than a decline is the main thing coaches can offer.

Timing varies enormously between individuals

Young people of the same age can be at entirely different stages of maturation, and the spread is widest around adolescence. This means a squad grouped by birth year contains bodies at very different developmental points doing identical sessions. Early maturing athletes are temporarily larger and stronger, which is frequently mistaken for greater athletic potential.

Later maturing athletes are frequently overlooked, despite the difference being one of timing rather than of eventual capability. The gap is widest in the middle of adolescence and has largely closed by the end of it, long after most selections were made.

The consequences for selection

Selection decisions made during this window frequently reward maturation rather than the qualities they intend to identify. Athletes selected on the basis of early physical advantage may struggle later when their peers catch up in size. Athletes deselected during this period often leave the sport before their own development has had a chance to occur.

Some organisations now group by maturation status rather than by age for parts of their programme in response. These approaches require assessment methods that must be applied appropriately and with the involvement of qualified staff.

Why load during this period is handled carefully

Growing bone includes regions that behave differently from mature bone and respond differently to repeated loading. This is why guidance on training volumes for young athletes exists in most sports and is treated as a safeguarding matter.

Nothing about the appropriate training load for a particular child can be determined from general information. Those decisions belong with qualified coaches working within their sport's guidance and with the child's clinician where there is any concern.

What a young athlete needs to hear

The most useful message during this period is that the awkwardness is temporary and reflects growth rather than lost ability. Athletes who are told this tend to persist through a phase that otherwise produces a great deal of dropout. Coaches who reduce technical expectations temporarily and emphasise participation generally keep more athletes in the sport.

The alternative, treating a growth-related dip as a decline in commitment, loses athletes who would have been fine within a year. Explaining the mechanism also gives a young athlete a way to understand their own body rather than simply enduring a confusing period.