Your child is training more than before: extra athletic preparation, gym even on Saturdays, never skips a session. And their performance is getting worse. They come home, eat little, shut themselves in their room, sleep badly and in the morning are a brick wall.
The instinctive reaction, both theirs and sometimes the coach's, is to train even harder. It is exactly the move that closes the trap.
The short answer: when performance drops while the load goes up, the problem is not that there is too little load, it is recovery. And before talking about motivation or character, one thing almost nobody checks needs looking at: whether they are eating enough for how much they train and, at the same time, for growing.
Three different things we all call "overtraining"
In everyday language "overtraining" covers any tiredness. In the literature there are three distinct states, which the joint consensus of the European College of Sport Science and the American College of Sports Medicine separates as follows.
Functional overreaching is the short-term drop in performance, without serious psychological symptoms or lasting consequences, which after recovery leads to improvement: after a heavy week you perform worse, then you perform better. It is training that works.
Non-functional overreaching appears when the balance between load and recovery is not respected. The drop in performance remains, and it takes weeks to get out of it.
The overtraining syndrome is the step beyond: the authors describe it as a prolonged maladaptation involving not only the athlete but also biological, neurochemical and hormonal mechanisms. Here the timescale is measured in months.
One clarification: that consensus concerns athletes in general, adults included, not adolescents in particular. The three definitions, however, have no age.
Now the honest part. The same document states that distinguishing non-functional overreaching from the overtraining syndrome is very difficult: it depends on the clinical outcome and on a diagnosis of exclusion, because the signs are often the same. It is commonly thought that the symptoms of the true syndrome are more severe, but the authors write that there is no scientific evidence either to confirm or to refute this. And on the markers (hormones, performance and psychological tests, biochemical and immune indices), none meets all the criteria to be accepted as a diagnostic tool.
Put simply: there is no blood test that will tell you. What there is, is observation of your child's real week.
The signs you can notice yourself
The American Academy of Pediatrics clinical report of 2024 describes the systemic consequences of prolonged periods in which the load exceeds recovery: drop in performance, increased risk of injury and illness, and alterations of the endocrine, neurological, cardiovascular and psychological systems. In everyday family life, it looks like this.
- Performance drops while effort rises. It is the most specific sign and the most ignored, because it is read as lack of willpower.
- Sleep does not restore. Not "sleeps little": sleeps and wakes up tired, or struggles to fall asleep precisely after evening training.
- Mood changes. Irritability, withdrawal, performance anxiety that was not there before.
- Illnesses keep coming back. Colds and viruses every three weeks in a young person who never used to get ill.
- Motivation evaporates. The same report defines burnout as physical or mental exhaustion with a reduced sense of accomplishment that leads to devaluing the sport, and it is one of the early causes of dropout from youth sport. A young person looking for excuses not to go to the gym has not become lazy in two months.
How common is it? A study of 376 young English athletes (mean age 15.1 years, 19 sports, from club to international level) found that 29% reported having gone through at least one phase of non-functional overreaching or overtraining, defined as persistent daily tiredness plus a significant and prolonged drop in performance. The incidence was higher in individual sports, in girls and at the highest levels.
A counterintuitive detail: in that study training load was not a significant predictor. It is an investigation based on retrospective questionnaires, and it should be taken for what it is, but the lesson holds: overtraining is not just a matter of hours. It is the relationship between everything you ask of a young person (sport, school, sleep, food, pressure) and what you give back.
Red flags: when not to wait
These are not situations to "keep an eye on": they need assessing, with an explicit threshold.
Stress fractures, especially if it is not the first. A localised bone pain that flares under load, worsens session after session and does not go away with a few days of rest. The first one may be a progression error. From the second one onwards, energy availability should be investigated, not just the bone.
Amenorrhoea. Here the thresholds are those of current clinical definitions, not the result of a single study: the first period that does not arrive by the age of fifteen; a period that stops for three months or more; very infrequent periods, fewer than nine in a year. None of these is the normal consequence of training a lot, and "it happens to athletes" is the most effective way to lose years of bone health.
Weight loss while the load rises. Weight that drops, or stays still while height increases, in a young person who is training more. Together with: skipping meals, cutting out whole food groups, counting calories, training in secret beyond the team, a new and persistent focus on the body in the mirror.
When two of these three appear together, it is not the moment to wait for the end of the season.
The part little known: are they eating enough for how much they train?
Low energy availability is the condition in which the energy from food does not cover the expenditure from exercise, and what is left for the body to run everything else is too little. When it persists, it is called RED-S, relative energy deficiency in sport.
The 2023 International Olympic Committee consensus describes it as a syndrome of negative consequences for health and performance in athletes of both sexes exposed to low energy availability, and notes that since the 2018 consensus over 170 original studies have come out, including new data on the overlap with mental health and on the impact in males.
The decisive point for a teenager is this: the body is not only training, it is also growing. A practical review of 2023 on RED-S in adolescents, males and females, lists the effects on mental wellbeing, bone, the endocrine system and metabolism, and notes that it presents to the most varied specialists depending on the symptom: a bone stress, an absent period, anxiety and low mood, or simply performance that does not rise.
The bone account weighs most, because it is not recovered later. The National Osteoporosis Foundation position statement of 2016, built on a systematic review, establishes that lifestyle choices influence 20-40% of the peak bone mass that will be reached as an adult. Adolescence is the window in which that asset is built, and a year of deficit in that window is not recovered with one good season at twenty-five.
A concrete signal, though observational, comes from a cross-sectional study of 161 girls and young women aged 14 to 26 (97 amenorrhoeic athletes, 32 athletes with regular periods, 32 non-athletes). At the radius, a bone that does not carry body weight, amenorrhoeic athletes had a lower proportion of plate-like trabeculae, fewer plates and lower connectivity than athletes with regular periods. And among the amenorrhoeic athletes, those with repeated stress fractures had the worst microarchitecture. It is a snapshot at a single moment: it shows differences between groups, it does not prove that amenorrhoea is what causes them.
There is, however, a nuance that makes the problem invisible: at the tibia, a bone that carries weight, the athletes, including the amenorrhoeic ones, were doing better than the non-athletes. Sport protects the bone where it loads it; the damage hides where the load does not reach.
On the Italian picture there is a recent figure: a cross-sectional study of 288 Italian female athletes aged 15 to 40, three quarters under 25, found irregular cycles in 33%. "Lean" sports and overestimating one's own body image were associated with a higher risk of irregularity (adjusted odds ratios 2.02 and 3.83).
RED-S is not "a girls' issue"
This is the part that is almost always skipped, because for years only the female Triad was discussed. The male picture has its own document, signed in 2021 by the Female and Male Athlete Triad Coalition: it is not the same thing as the IOC's RED-S, it is a narrower model, and it describes the Male Athlete Triad as three linked conditions: energy deficiency, functional hypothalamic hypogonadism, and low bone mineral density with or without stress injuries. It is explicit about who it affects: it is more common in adolescent and young adult male athletes who do endurance and weight-category sports, from middle distance running to judo to lightweight rowing.
Here too the authors state the limits: in men the subclinical intermediate outcomes are less clearly defined than in women, and the available data suggest that a more severe energy deficit is needed to affect reproductive function and skeletal health. More research is needed to quantify it.
Seen from the parent's side: in boys the warning bell is missing. There is no period that stops to signal that something is wrong; there are recurring injuries, performance that does not rise, tiredness and mood.
How much is too much: hours relative to age
The rule that circulates in recommendations is simple: no more weekly hours of organised sport than years of age. A twelve-year-old, no more than twelve hours; a sixteen-year-old, no more than sixteen. Where does that number come from? From a case-control study of 1,190 young athletes aged 7 to 18, recruited at two American sports medicine centres and compared with healthy peers. The injured were older (14.1 years against 12.9) and did more hours of organised sport (11.2 against 9.1 a week). Taking age and weekly hours into account:
- those who did more weekly hours of sport than years of age had roughly double the odds of a serious overuse injury: odds ratio 2.07, 95% confidence interval 1.40 to 3.05;
- those with a ratio of organised sport to free play above 2 to 1 had higher odds of the same injury: odds ratio 1.87, 1.26 to 2.76;
- specialising in a single sport was an independent risk factor, for injury in general (odds ratio 1.27) and for serious overuse injury (1.36).
And one result that disarms a very common alibi: growth rate was not associated with risk, 4.8 centimetres a year in both groups. "It is because they are growing" explains less than you might think.
To be clear about it: this is a case-control study, evidence level 3, in American clinics. It shows an association, not a cause. But it is the best estimate available, and the threshold it yields is easy to use with a calendar in hand.
On early specialisation the direction is consistent. A review of 2013 in Sports Health concludes that for most sports there is no evidence that intense training and specialisation before puberty are necessary to reach high levels, while the risks listed are more injuries, more psychological stress and early dropout from sport: hence the recommendation to postpone specialisation until late adolescence. The American Academy of Pediatrics clinical report of 2016 is more cautious but points in the same direction: when specialisation comes too early, negative physical and psychological effects can appear, and anyone who trains intensely, specialised or not, remains exposed to adverse effects.
If you have a younger child who still has to choose, you will find the maturation stages in When a child is ready for a sport.
Sleep is training, not free time
In a study of 112 adolescent athletes at an American school (mean age 15), hours of sleep per night and year of study were the best independent predictors of injury: those who slept less than eight hours a night had 1.7 times the odds of having been injured compared with those who slept eight or more.
Precision matters here: the 95% confidence interval runs from 1.0 to 3.0, that is, it includes the value of no effect, with p 0.04. It is a borderline result, in a small sample and at a single school: a clue, not proof. But the cost of acting, getting a teenager to sleep eight hours, is zero.
In practice the conflict is training that ends at 10:30 pm, dinner at 11 pm and an alarm at 6:40 am. It is not laziness: it is arithmetic.
Rest is part of training, not a pause
Something to tell your child: training does not make you stronger while you do it, it makes you stronger while you recover. In practice:
- genuinely free days every week, not "active recovery", which is another training session with another name;
- breaks during the year, with a change of activity: it is also a way to reduce specialisation without removing it;
- room for free play and other sports: in the case-control study it was precisely the imbalance in this share (more than two hours of organised sport for every hour of free play) that was associated with more serious overuse injuries;
- a heavy week followed by a light one, instead of twelve identical weeks climbing upwards.
And if the question is "but will they lose their place in the team?", look at what the alternative costs. A serious overuse injury does not close with a week of unloading; a stress fracture of the pars interarticularis, the picture described in Spondylolysis in the young athlete, keeps them out for even longer. Burnout takes them all, because that young person leaves the sport.
How we can help
A guided pathway serves three purposes: putting the real week in writing, meaning training, school, sleep and meals; recognising which of the three pictures you are looking at and whether a step with a doctor is needed; and putting the load back in order without stopping everything, which is the opposite mistake.
It works well by video call, because most of it is listening, calendar and dosage. With Ri-Hub Junior you start with a free first consultation of twenty minutes with a physiotherapist registered with the Register who works with children and teenagers. From age 11 to 18 the standard session costs 29,90 €.
Two things we do not do: we do not treat complex neurological and neuromuscular conditions online, and we do not replace medical assessment where it is needed. If there is amenorrhoea, if weight drops, if stress fractures keep recurring, the pathway goes through the paediatrician or sports doctor, and the nutritional side is entrusted to whoever looks after that. We work on load, movement and recovery.
In three lines
If they train more and perform worse, the load is not too little: it is too much for the recovery they have. Look at sleep, mood, recurring illnesses and, above all, whether they are eating enough for how much they train and how much they grow. Amenorrhoea, repeated stress fractures and falling weight are not the price of sport: they are the signal to stop and get seen.
If the pain is instead localised below the kneecap and appears with growth, the picture is different: Osgood-Schlatter, the teenager's knee.
If it always hurts in the same spot, there is a documented reason: A child who always hurts in the same place.
The most overlooked variable of all, and the one with the best evidence, is sleep: How much a child who does sport should sleep.
And for a girl who trains, the question about her period: Periods and training: does it really change anything?
Sources
- Prevention, diagnosis, and treatment of the overtraining syndrome: joint consensus statement of the European College of Sport Science and the American College of Sports Medicine, Medicine & Science in Sports & Exercise, 2013
- Overuse Injuries, Overtraining, and Burnout in Young Athletes, Pediatrics (American Academy of Pediatrics clinical report), 2024
- Prevalence of nonfunctional overreaching/overtraining in young English athletes, Medicine & Science in Sports & Exercise, 2011
- 2023 International Olympic Committee's (IOC) consensus statement on Relative Energy Deficiency in Sport (REDs), British Journal of Sports Medicine, 2023
- Relative Energy Deficiency in Sport (RED-S) in Adolescents, A Practical Review, International Journal of Sports Medicine, 2023
- The Male Athlete Triad, A Consensus Statement From the Female and Male Athlete Triad Coalition, Part 1: Definition and Scientific Basis, Clinical Journal of Sport Medicine, 2021
- Altered trabecular bone morphology in adolescent and young adult athletes with menstrual dysfunction, Bone, 2015
- Determinants of menstrual dysfunction in the female athlete triad: A cross-sectional study in Italian athletes, Psychology of Sport and Exercise, 2024
- The National Osteoporosis Foundation's position statement on peak bone mass development and lifestyle factors: a systematic review and implementation recommendations, Osteoporosis International, 2016
- Sports-specialized intensive training and the risk of injury in young athletes: a clinical case-control study, The American Journal of Sports Medicine, 2015
- Sports specialization in young athletes: evidence-based recommendations, Sports Health, 2013
- Sports Specialization and Intensive Training in Young Athletes, Pediatrics (American Academy of Pediatrics clinical report), 2016
- Chronic lack of sleep is associated with increased sports injuries in adolescent athletes, Journal of Pediatric Orthopaedics, 2014
Sources last checked: September 2026.
