The Missed Period Isn’t “Normal” for Any Athlete: Recognising RED-S in Team Sports
RED-S in team sports doesn’t get talked about nearly as often as it does in dance — but a missed or irregular period is just as significant a signal in football, hockey, netball and athletics as it is at the barre. “Losing your period is just part of being a dedicated dancer” is a line most dance teachers have heard some version of. The equivalent in team sports rarely gets said out loud at all, not because the pattern is rarer, but because fewer people are looking for it there.
This is the plain-English guide to RED-S in team sports: what a missed or irregular period actually means, why it’s so easily waved off as normal whatever you play, and when it’s worth an actual conversation rather than something to watch and wait on.
What a missed period is actually telling you
A menstrual cycle takes a reasonable amount of energy to run, and it isn’t essential in the way breathing or circulation are. So when the body is consistently short on fuel relative to how hard it’s training, it makes a trade-off: non-essential systems get deprioritised so the essential ones keep working. Reproductive function is usually first on that list.
That’s what’s happening, in plain terms, behind a missed or irregular period in an athlete — sometimes called athletic or exercise-induced amenorrhea. It isn’t a malfunction and it isn’t random. It’s the body responding sensibly to a genuine shortfall, the same way it would in anyone underfuelled for long enough. Which is exactly why it’s worth listening to rather than working around.
Why it gets waved off as “normal” — in every sport, for different reasons
In dance, the dismissal usually sounds like a shrug: of course training that hard affects your cycle, that’s just what dancers’ bodies do. It’s been said for long enough that it’s absorbed as fact rather than questioned as a symptom.
In team sports, the dismissal tends to come from a different angle — not “that’s normal for this sport,” but “RED-S isn’t really relevant to this sport.” Relative Energy Deficiency in Sport still gets treated, in a lot of coaching and PE settings, as something that mainly affects distance runners and dancers. That means a footballer, hockey or netball player who mentions a missed period is less likely to have anyone connect it to training and fuelling at all — not because the connection is any weaker, just because nobody’s looking for it there yet.
Either way, the effect is the same: a genuine signal gets filed under “normal for the sport” instead of getting a proper look.
What energy availability actually means
The concept underneath all of this is energy availability — not calories, not weight, just whether there’s enough fuel left over, once training has taken what it needs, to run everything else the body’s meant to be doing: growth, bone development, hormone regulation, immune function, tissue repair. The reproductive system is part of that list, which is why a missed period is one of the more visible signs something’s off, but it’s rarely the only one.
The other signs tend to travel with it: energy that’s fine at the start of a session and gone by the end, niggling injuries that keep recurring without an obvious cause, mood or concentration that dips on the heaviest training days. None of these are a diagnosis alone. Together, or persistent, they’re the pattern behind RED-S, and none of them are specific to any one sport.
It’s also worth saying plainly: this isn’t about how anyone looks. A missed period doesn’t require visible weight loss to be a real signal, and RED-S can affect an athlete at any size — that’s a large part of why it gets missed for so long, across every sport, not just the ones we tend to associate with it.
When it’s worth acting, not just watching and waiting
A single missed cycle after illness, travel or an unusually heavy training block isn’t automatically a red flag — the body responds to short-term stress in all sorts of ways. What’s worth acting on is a pattern: periods that have stopped for three months or more, a cycle that’s never really settled into anything regular for a training teenager, or a missed period alongside any of the other signs above. Waiting to see if it sorts itself out on its own is the single most common reason this drags on for months, or years, longer than it needs to.
What to actually do about it
The good news is that a lot of this doesn’t need to wait for an appointment.
Start increasing fuel now, at home, without waiting for a diagnosis. Breakfast that actually happens, lunch treated as a full meal rather than something to tide you over, carb-based snacks before training, a dinner that supports recovery — matching intake to training load is the actual treatment in most cases, and it’s the one lever anyone can pull immediately, before any referral comes through.
Keep a simple record, not a diagnosis. A few lines noting roughly when periods have (or haven’t) happened, training days and intensity, and anything noticed about eating — meals skipped, “not hungry” after training, food rules creeping in — turns a vague worry into something concrete. A clinician takes “no period for four months, training six days a week, breakfast most days skipped” far more seriously than “I think it’s been a while.”
See a sports dietitian in parallel with, not instead of, medical input. You don’t need a GP referral to book in with a dietitian who works specifically with RED-S and energy availability in young athletes — it’s often the faster route to actually addressing the fuelling side, and it can run alongside anything happening medically rather than waiting for it to conclude first.
If you do see a GP, ask for the right things by name. Mention RED-S, or relative energy deficiency in sport, specifically, rather than just “her period’s stopped” — a named, recognised condition tends to get a different response than a general concern. Ask whether a hormone panel (oestradiol, FSH/LH, alongside general bloods) has been considered, and for periods missing six months or more, ask specifically about a bone density (DEXA) scan. Adolescence is when peak bone mass is built, and that window doesn’t reopen — which is exactly why prolonged amenorrhea at this age tends to be treated as more urgent than the same pattern later in life.
Bring the coach or school in, with the athlete’s agreement. A coach who knows to keep an eye on training load, and on how food gets talked about around the squad, is genuine extra support rather than an overstep — the athlete decides how much detail is shared. “They’re getting some support with fuelling, please keep an eye on how training’s landing” is usually enough.
If a GP has already said not to worry
This comes up often, and it isn’t a sign that anyone’s failed to advocate properly. Menstrual health in athletes specifically — as opposed to period problems in general — isn’t yet a routine part of general practice training, so a GP working through a short appointment without a sports medicine background may reasonably default to “some irregularity is common, keep an eye on it.” That’s a sensible general answer to a general question. It isn’t the right answer to this specific one.
If that’s happened, a few things are worth trying next, in roughly this order:
Go back and name RED-S or the female athlete triad specifically, rather than describing the symptom alone — it changes the conversation from “is this normal” to “has this been assessed for a known condition.”
Ask for a referral to sports medicine, or to a gynaecologist or endocrinologist with a sports background, rather than staying in general practice. These are the specialities that see this pattern regularly and are set up to investigate and treat it properly, including the bone health side.
Ask specifically about a bone density scan if it’s been six months or more — this is a concrete, reasonable ask that’s harder to wave off than “should we be worried.”
A second opinion is a normal next step, not an overreaction. Being told not to worry once doesn’t settle it if the pattern is real and ongoing. Booking directly with a sports dietitian or a sports medicine clinician, without waiting on a second GP appointment, is entirely reasonable too.
If this is sounding familiar
If you’re an athlete whose cycle has gone quiet and you’ve been telling yourself it’s just what happens when you train hard, or a parent who’s already had the “try not to worry” conversation and it didn’t sit right — the steps above are a genuine starting point, not just a reason to keep watching and waiting. For additional information on how to fuel your training, have a look at https://thebluebirdcentre.com/teen-sports-nutrition/ or https://thebluebirdcentre.com/relative-energy-deficiency/. If you would like some snack ideas pre-training, click on this link to download a helpful snack guide.
Get in touch to find out more about sports nutrition support for young athletes, or to talk about what this could look like for your school or club.
