The growth spurt in young female athletes: what actually changes (and what is not their fault)

In young female athletes peak height velocity arrives at a mean age of about 11.2 years — but the individual range is enormous: a squad of thirteen-year-olds contains bodies years apart in maturation. Meanwhile bone mineralises roughly six months after it has lengthened. What the data actually say — and why, in girls, the evidence linking growth to injury is still limited.

There is one year, for every girl, in which the body changes faster than she can get used to it. She shoots up, her shoes stop fitting, movements that were automatic feel less precise. In sport that year has a technical name — peak height velocity — and a whole mythology has grown around it: the year you get injured, the year you turn clumsy, the year you "just have to wait out". Almost none of that is established in girls. What is documented, though, is enough to change something in the gym.

In brief

  • In young female athletes the mean age at peak height velocity is estimated at 11.18 years, with a 90% credible interval from 8.62 to 12.94 (Lima et al., 2024): chronological age says nothing about where a body is.
  • Peak bone mineral accrual comes roughly six months after peak height velocity (Bailey et al., 1999): for a period, bone is longer but not yet as dense.
  • In girls, evidence linking maturation and injury is limited; evidence linking maturation and knee risk factors in jumping and landing is moderate (Zoellner and Whatman, 2026).
  • The strong data on rapid growth and injury come from male academies: above 7.2 cm/year, incidence up to 2.38 times higher (Monasterio et al., 2024).
  • "Adolescent awkwardness" is a contested hypothesis, and in girls it is almost unexplored (Borato et al., 2025).

At what age does the growth spurt happen in girls?

On average around 11-12, but the average is of little use here. A longitudinal meta-analysis pooling 14 studies and 21 independent samples of young female athletes estimates age at peak height velocity at 11.18 years, with a 90% credible interval from 8.62 to 12.94 years (Lima et al., 2024). That width is not a flaw in the analysis: it is reality. It means a changing room of thirteen-year-olds holds girls who passed their spurt three years ago and girls going through it right now.

The Cracow longitudinal study, which followed young athletes and non-athletes, gives consistent means: 11.7 years for girls in team sports, 12.2 in athletics, 12.5 in individual sports, 11.9 among non-athletes (Kozieł et al., 2024). It should be said plainly that the female groups were tiny — from 6 to 22 girls — so those numbers indicate an order of magnitude, not a norm on which to build decisions.

There is one operational conclusion, and it is the most underrated: year of birth is not a maturation indicator. Two athletes in the same age category can be biologically years apart.

Is it true that injuries increase during the growth spurt?

In girls, as of today, it is not established. That is the uncomfortable answer, and it is the most recent one. A systematic review published in Physical Therapy in Sport screened 31 studies — 10 on injury, 21 on risk factors — and concludes that «evidence supporting an association between injury and maturation was limited», while there is moderate evidence that maturity status is associated with potential risk factors, mainly in lower-limb biomechanics during jumping and landing, that is, in knee territory (Zoellner and Whatman, 2026).

The clearest numbers on rapid growth and injury do exist, but they come from another population. In an elite football academy, following 84 male players across twenty seasons, growth above 7.2 cm per year before the spurt was associated with injury incidence 1.65 and 2.38 times higher than moderate and slow growth, and the period around the spurt carried the highest burden of all: 136 days lost per 1,000 hours of exposure (Monasterio et al., 2024). That is robust data — and it is on boys. Transferring it wholesale to thirteen-year-old girls would be exactly the kind of shortcut this blog tries to avoid: it shows where it is worth looking, not what to expect.

For a sense of the real scale of the problem: in young female athletes overall injury incidence is 4.4 per 1,000 hours (16.5 in matches against 2.2 in training), 40% sustain at least one time-loss injury, 67% of injuries are to the lower limb — ankle 23%, knee 16% — and the mean days lost is 10 (Beech et al., 2024). That is the backdrop against which growth should be read: not as the cause, but as one of the things that make a period more delicate.

What actually changes in a fast-growing body

Three things are documented, and they are enough to justify caution.

1. Bone lengthens before it mineralises. In the University of Saskatchewan longitudinal study, in 53 girls and 60 boys followed for six years, peak bone mineral content accrual occurs roughly six months after peak height velocity (Bailey et al., 1999). In that interval bone is already longer, but not yet as dense. This is normal physiology, not pathological fragility — and it is one reason to take seriously localised bone pain that does not settle, as described in stress fractures in young female athletes.

2. Levers get longer, and landing changes. Longer segments mean different lever arms for the same muscular force. This is where the only evidence rated "moderate" in the 2026 review sits: maturation is associated with how an athlete lands (Zoellner and Whatman, 2026). Consistently, a longitudinal study of 315 young athletes showed that after puberty girls land with significantly greater dynamic knee valgus than boys (-9.3° against -3.6°; p<0.001), while in boys the value does not change over the years (Ford et al., 2010). It is the same mechanism that makes puberty pivotal for the ACL.

3. Repeated load meets structures in transition. The growth zones — the apophyses, where tendons attach to bone — are active precisely in this phase. This is the territory of the knee that has hurt for months: pain that does not come from a single trauma but from load accumulating while the body changes.

Is "adolescent awkwardness" real?

It is a contested hypothesis, not a fact. It is worth saying because it is the idea that most often turns into a judgement about a girl.

The hypothesis comes from a systematic review of 33 studies documenting that several sensorimotor mechanisms are not yet mature in adolescence, opening the possibility of a phase of greater motor awkwardness (Quatman-Yates et al., 2012). But a 2025 narrative review, returning to the topic fourteen years later, is far more cautious: there is no shared definition and no standard measurement method, and «some studies observed a decline in sensorimotor function during the growth spurt, while others show continuous improvement or high variability between youth». Sprinting and jumping in particular tend to improve during growth rather than deteriorate; what signs of decline exist are mostly in balance. And, decisively for us, «few studies have analysed these changes in adolescent girls» (Borato et al., 2025).

In practice: if an athlete seems less precise during a period of rapid growth, "her body is changing" is a more useful and more accurate hypothesis than "she has got clumsy". The first leads to adapting the work; the second leads a girl to think she is no longer any good — one of the ways drop-out begins.

How to tell where growth is, without medicalising anything

The most useful method is also the simplest: measure height every three months, always in the same conditions (same time of day, no shoes, back to the wall), and look at velocity — how many centimetres in how much time — not at the absolute value. Fast growers show up this way, not by how they look.

Equations exist that estimate distance from peak height velocity from age, stature and sitting height, revised and validated in independent longitudinal samples (Moore et al., 2015). They are useful for planning, but they remain estimates with wide error margins, the wider the further you are from the spurt: they do not tell a girl who she is, they tell a coach where to pay attention.

What a club does not need: bone-age X-rays, pubertal staging, maturation rankings on the noticeboard. Those are clinical acts, and in youth sport they are also a matter of dignity and privacy — the same principle for which, as we write in how to coach teenage girls, a club needs aggregated signals, never the individual health data point.

What changes on Monday

The growth spurt is not a danger to fear: it is a window to accompany. The worst thing you can do is not training through growth — it is expecting a girl whose body is changing to train exactly as she did six months ago.

Sources

This article is for information and education only and does not constitute medical advice or a diagnostic tool. Most of the studies cited are observational and describe associations, not cause and effect; where data come from male samples this is stated explicitly. Pain lasting more than two weeks, joint swelling, or localised bone pain should be taken to a paediatrician or sports physician.

At what age does the growth spurt happen in girls?

On average around 11-12, but the individual range is very wide. A longitudinal meta-analysis of 14 studies and 21 samples of young female athletes estimates mean age at peak height velocity at 11.18 years, with a 90% credible interval from 8.62 to 12.94 years (Lima et al., 2024). In the Cracow longitudinal study, means for girls ranged from 11.7 years in team sports to 12.5 in individual sports, against 11.9 in non-athletes — but on very small samples (6-22 girls per group), so read them as an indication, not a norm (Kozieł et al., 2024). The practical point: the date on the birth certificate says nothing about where a body is in its growth.

Is it true that injuries increase during the growth spurt?

In girls, as of today, it is not established. A 2026 systematic review of 31 studies (10 on injury, 21 on risk factors) concludes that «evidence supporting an association between injury and maturation was limited», while there is moderate evidence that maturity status is associated with knee injury risk factors, mainly in jump-landing biomechanics (Zoellner and Whatman, 2026). The clearest data on rapid growth and injury come from male football academies: there, growing more than 7.2 cm a year is associated with injury incidence up to 2.38 times higher, and the period around the spurt carries the highest burden of days lost (Monasterio et al., 2024). That is male data: it says where to look, not what to expect in girls.

Is 'adolescent awkwardness' real?

It is a reasonable hypothesis, not a confirmed fact — and in girls it has barely been studied. A systematic review of 33 studies found that several sensorimotor mechanisms are not yet mature in adolescence, raising the possibility of a phase of greater awkwardness (Quatman-Yates et al., 2012). A 2025 narrative review is more cautious: some studies observe a decline in sensorimotor function during the growth spurt, others continuous improvement or very high variability; sprinting and jumping tend to improve, and «few studies have analysed these changes in adolescent girls» (Borato et al., 2025). The practical consequence: do not label a girl clumsy on the basis of a phase that may not exist the way we imagine it.

How do you tell where an athlete is in her growth, without medical tests?

By measuring height at regular intervals and looking at the velocity, not the value. A fixed wall measure and one measurement every three months, always in the same conditions, is enough: what matters is how many centimetres in how much time. Equations exist that estimate distance from peak height velocity from age, stature and sitting height (Moore et al., 2015), but they remain estimates with wide error margins: they are for planning, not for labelling. A sports club needs no wrist X-rays and no pubertal staging: those are clinical acts, not gym tools, and treating them as such protects girls' privacy.

Why is bone more vulnerable exactly when a girl is growing?

Because mineralisation follows lengthening. In the University of Saskatchewan longitudinal study, in 53 girls and 60 boys followed for six years, peak bone mineral accrual occurs roughly six months after peak height velocity (Bailey et al., 1999). In the interval between the two, bone is already longer but not yet as dense. This is normal physiology, not pathology — but it is a good reason not to increase volume and intensity in exactly that period, and to take seriously localised bone pain that does not settle.

What can a club actually do?

Four things, all at almost no cost. 1) Measure height every three months and keep a record, so you notice who is growing fast. 2) Do not increase volume and intensity in a quarter when an athlete has grown a lot: hold the load steady and work on technique and control. 3) Keep the neuromuscular warm-up — 20 minutes, twice a week — which in athletes aged 13-19 cuts ACL rupture risk by around 60% (Petushek et al., 2019). 4) Change the language: «your body is changing and we are adapting the work» instead of «you have been sloppy lately».