A coach's words: how staff knowledge and language change athletes' health

How much does what a coach knows and says actually matter? Athletes who perceive their coach as very knowledgeable report 36% fewer RED-S symptoms; those who have received comments about their body are four times more likely to change how they eat (33% vs 7%). Staff language is not a neutral backdrop to training: it is a measurable health variable. The data, the limits, and what to do with it tomorrow in the gym.

In a locker room, a line like "you're a bit out of shape compared to last year" is never just a line. To the person saying it, it can be an offhand nudge; to a fourteen-year-old girl, it can become the starting point for weeks spent counting calories. The research puts it plainly: what staff know and say is not a neutral backdrop to training — it's a variable that shows up, measurably, in athletes' health. In both directions.

In short

  • A coach perceived as very knowledgeable is associated with 3.2 RED-S symptoms on average, versus 4.3 for one perceived as uninformed: -36%.
  • Body comments that cause discomfort are linked to 4 times higher odds of changing how one eats (33% vs 7%) and to +34% RED-S symptoms.
  • Those who should know often don't: fewer than 50% of athletes knew the term RED-S, and 30% were told by a medical professional that losing your period through physical activity is "normal".
  • The lever isn't turning coaches into doctors, but giving them basic awareness and guidance on what not to say — and giving athletes a channel that doesn't force them to expose themselves.

How much does what a coach knows actually matter?

Enough to show up in their athletes' symptoms: 36% fewer, in the available data. Most conversations about athletes' health stop at the athlete: what she eats, how she sleeps, how she manages her cycle. One figure from the Female Athlete Health Report 2023 — a survey of 769 athletes conducted in the UK by two athlete-led organisations (Project RED-S and Kyniska Advocacy) — shifts the centre of gravity onto the staff.

Athletes who rated their coach as "very well informed" about female athlete health reported an average of 3.2 RED-S symptoms. Those who perceived their coach as uninformed: 4.3. A difference of 36%, in exactly the direction you'd expect if staff knowledge really mattered.

RED-S — Relative Energy Deficiency in Sport, the low-energy-availability syndrome that erodes the cycle, bones, the immune system and mood — is not a niche topic: in the same sample, more than half of the athletes had at least two symptoms, and fewer than 50% even knew the term before the survey. This is precisely the kind of problem that goes unnoticed if no one around the athlete knows what to look for.

One necessary caveat: this is not a randomised study and does not prove cause and effect. But it is one of the very few datasets that explicitly links the perceived knowledge level of staff to a health outcome measured in athletes, with a number attached. And the direction is consistent with the rest of the literature.

Can a comment about an athlete's body change how she eats?

Yes, and the effect is measured: four times the odds of changing her eating. If knowledge helps, carelessness does concrete damage. In the same report, 53% of athletes had received, in a sporting context, comments about their body that made them uncomfortable. Those who had were four times more likely to change how they ate to "fit in" with their sport (33% vs 7%) and reported 34% more RED-S symptoms.

The point is that the effect matters, not the intention. "You should lean out a bit", "you're heavier this year", even a clumsy compliment: in an adolescent's mind these can turn into a dietary rule. And the ground is already fragile — 74% of athletes had, at some point, felt "like they didn't look like an athlete", and 91% had worried about how many calories they were eating. In that context, a coach's comment doesn't land in a vacuum: it lands on a worry that is often already there.

The paradox: those who should know, often don't

You'd think the professionals, at least, would have it straight. Not always. In the UK report, 30% of athletes were told by a healthcare professional that losing or delaying your period through physical activity is normal — which is wrong, because amenorrhoea is not a harmless side effect of training but a warning sign. And a synthesis of the clinical guidelines notes that fewer than half of doctors, coaches, physiotherapists and athletic trainers can identify all three components of the Female Athlete Triad (Romano & Sass, 2025, NASPAG Clinical Opinion).

The training gap also shows in where information comes from. In the same UK report, specific support on female athlete health had come for 49% from the internet and social media, for 16% from a GP, for 4% from a national sports federation and for 0.12% from school. Translated: the institution that should be guiding these girls — the club, the federation, the school — is almost absent, and a phone feed fills the void.

Does it also apply at 13-14?

Here honesty is required. The UK report's sample has an average age of 32: it captures a pattern in the adult athletic population, not a prevalence among 13-14-year-old athletes, who are at the heart of BAB's work. Taking those numbers and pasting them onto adolescents would be wrong.

Two elements, though, indicate that adolescence is exactly the window in which this culture makes the difference:

The adult pattern, in other words, is not destiny: it's what happens when the culture isn't built at the right moment. And the right moment is now.

What staff can do, concretely

None of this asks a coach to become a doctor. It asks for a few sustainable habits:

And at club level: the athletes themselves say what they want — 56% ask for a website with reliable resources, 34% for online workshops. Minimal staff training isn't a luxury: in the report it is one of four explicit recommendations (mandatory RED-S training in coach certification pathways).

BAB's role

BAB works on exactly this dual front. For the athlete it provides a private space to recognise her own signals and an educational layer that fills the training gap — that "I learned it on my own" which applies to most athletes. For staff it provides the two things the data flag as decisive: basic awareness (including what not to say, because the "-34% / +34%" of body comments is a communication guideline, not a detail) and only aggregated, anonymous signals for the team — never an individual's cycle or health.

It's how you turn an attentive coach into an informed one without asking him to become something else, and how you give a girl a channel that doesn't force her into a conversation that, at fourteen, almost never happens. Because staff words count: you may as well make them a protective factor.

Sources

This article is for informational and educational purposes and does not constitute medical advice.

Does a coach have to become an expert in the menstrual cycle and RED-S?

No. A coach doesn't have to diagnose anything or know each athlete's individual data. But basic awareness matters: in the Female Athlete Health Report 2023 (769 athletes, UK), those who perceived their coach as 'very knowledgeable' reported an average of 3.2 RED-S symptoms versus 4.3 for those who perceived their coach as uninformed — 36% fewer. Even baseline staff knowledge is associated with a better health outcome.

Why is a comment about the body a problem if I say it 'to motivate'?

Because what counts is the effect, not the intention. In the same report, athletes who had received body comments that made them uncomfortable were four times more likely to change how they ate to 'fit in' (33% vs 7%) and reported 34% more RED-S symptoms. A remark made in passing can trigger behaviours that last for months.

What should a coach never say to an adolescent athlete?

The simplest rule is to take the body out of the vocabulary of the pitch: no comments on weight, shape or how an athlete "looks" — not to motivate, not even as a compliment. In the Female Athlete Health Report 2023, 53% of athletes had received body comments in a sporting setting that made them uncomfortable, and those who had were four times more likely to change how they ate (33% vs 7%). What works instead are questions about how she feels and what she can do: they describe the performance without judging the person.

How do you open the conversation without invading a girl's privacy?

By normalising without probing. A line like "this can be talked about here, and nobody judges you for it" opens the door without asking for a single private detail: the athlete decides whether, when and how much to say. It holds for periods, for pain, for fatigue and for the symptoms that get discussed even less. The practical difference is that a coach does not need to collect health information: they need to make it possible for a girl to talk to someone, and to know where to refer her.

Do these figures also apply to 13-14-year-old athletes?

They should be used with care: the UK report has an average age of 32, so it captures a pattern in the adult athletic population, not a prevalence among 13-14-year-olds. But other sources suggest adolescence is exactly when to act: peak bone formation happens between ages 10 and 14 (NASPAG, 2025), and already at 13-18 years, 44% of athletes believe that losing their period is a normal response to training (Armento et al., 2021). Misinformation — and the window to correct it — start early.